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475 Cards in this Set

  • Front
  • Back
Dermatological Hx should include:
•Signalment: age, sex, breed, color
•Chief Complaint
•Age of Onset
•Pruritus, Seasonality, Progression, Travel, Contagion, Response to therapy, Environment
•General Medical History
Com'n Skin Dz's younger than 6 months
-Black Hair Follicle dysplasia
-K9 muzzle furunculosis (K9 acne)
-Cutaneous asthenia
-Juvenile Sterile granulomatous dermatitis and lymphadenitis (juvenile Cellulitis)
-Viral papillomatosis
Com'n Skin Dz's in 1-3 year old animals
-K9 Atopic dermatitis
-Color dilution alopecia
Com'n Skin Dz's in animals older than 6 yo
-Sertoli Cell tumor assoc. dysplasia
-Superficial necrolytic dermatitis
General quality of skin and hair to be noted
Is the hair dull, dry, brittle, oily, or thin? Is the skin thinned, hyperelastic, or thickened? Are there any pigmentation changes or abnormalities? Are there obvious lesions that will need special attention during closer examination?
Types of Primary Skin Lesions
Types of Secondary Skin Lesions
-Epidermal Collarette
-Lichenification (can be seen w/ hyperkeratosis & pigmentation involved)
Types of Primary or Secondary Skin Lesions
-Follicular casts
-Comedo (blackheads)
Pustules may be:
Follicular, non-follicular, large w/ multiple follicles (usually immunosuppresive)
Most com'n sign of Sarcoptic mange
Alopecia and crusts around the ears
Terms used to describe lesion configuration
-Iris (target)
Com'n Lesions found on the Head
-Atopic dermatitis
-Juvenile sterile granulomatous dermatitis & lymphadenitis
Com'n Lesions found on the Ear
-Atopic dermatitis
-Food intolerance
-Fly bite dermatitis
-Solar dermatitis (feline)
Com'n Lesions found on the Eyelid
Com'n Lesions found on the Nasal Planum
-Discoid lupus erythematosus (collie nose)
-Nasodigital hyperkeratosis
-Pemphigus foliaceus
-Sterile pyogranuloma syndrome
-Uveodermatological syndrome
Com'n Lesions found on the Lips
-Indolent ulcer
-Oral papillomatosis
Com'n Lesions found in the Oral Cavity (mucosa)
-Eosinophilic granuloma
-Erythema multiforme
-Plasma cell stomatitis
-Pemphigus vulgaris
-Systemic lupus erythematosus
Com'n Lesions found on the Mucocutaneous Junctions
-Epitheliotropic lymphoma
-Erythema multiforme
-Mucocutaneous pyoderma
-Superfical necrolytic dermatitis (TEN)
Com'n Lesions found on the Chin
Com'n Lesions found on the Neck
-Feline atopy
-Flea bite hypersensitivity, feline
-Injection site reaction
Com'n Lesions found on the Ventral Chest
-Bacterial folliculitis
-Sternal callus
-Contact dermatitis
Com'n Lesions found in the Axillary region
-Acanthosis nigricans
-Atopic Dermatitis
-Malassezia dermatitis
Com'n Lesions found on the Back
-Atopic dermatitis
-Bacterial folliculitis
-Flea bite hypersensitivity
-Schnauzer comedo syndrome
-Seborrhea, primary
Com'n Lesions found on the trunk
-Bacterial folliculitis
-Sebaceous adenitis
Com'n Lesions found on the Abdomen
-Atopy, feline
-Eosinophilic plaque
-Psychogenic alopecia
-Solar dermatitis
-Contact dermatitis
-Atypical mycobacteriosis
-Pelodera derematitis
Com'n Lesions found on the tail
-Anal sac dz
-Food intolerance
Com'n Lesions found on the Legs
-Acral lick dermatitis
Com'n Lesions found on the Paws
-Adverse food reaction
-Foreign body
-Malassezia dermatitis
-Pemphigus foliaceus
-Plasma cell pododermatitis
-Contact dermatitis
-Superficial necrolytic dermatitis (NME)
Com'n Lesions found on/near the Claws
-Lupoid onychodystrophy
-Bacterial paronychia
-Systemic lupus erythematosus
-Pemphigus foliaceus
Superficial Skin Scraping
Performed over large area, collecting abundant material
-Taken from intact, crusted lesions of p's suspected of having Sarcoptes
-Elbows, chest, pinna margins com'n areas
Terms used to describe lesion configuration
-Iris (target)
Com'n Lesions found on the Head
-Atopic dermatitis
-Juvenile sterile granulomatous dermatitis & lymphadenitis
Com'n Lesions found on the Ear
-Atopic dermatitis
-Food intolerance
-Fly bite dermatitis
-Solar dermatitis (feline)
Com'n Lesions found on the Eyelid
Com'n Lesions found on the Nasal Planum
-Discoid lupus erythematosus (collie nose)
-Nasodigital hyperkeratosis
-Pemphigus foliaceus
-Sterile pyogranuloma syndrome
-Uveodermatological syndrome
Com'n Lesions found on the Lips
-Indolent ulcer
-Oral papillomatosis
Com'n Lesions found in the Oral Cavity (mucosa)
-Eosinophilic granuloma
-Erythema multiforme
-Plasma cell stomatitis
-Pemphigus vulgaris
-Systemic lupus erythematosus
Com'n Lesions found on the Mucocutaneous Junctions
-Epitheliotropic lymphoma
-Erythema multiforme
-Mucocutaneous pyoderma
-Superfical necrolytic dermatitis (TEN)
Com'n Lesions found on the Chin
Com'n Lesions found on the Neck
-Feline atopy
-Flea bite hypersensitivity, feline
-Injection site reaction
Com'n Lesions found on the Ventral Chest
-Bacterial folliculitis
-Sternal callus
-Contact dermatitis
Com'n Lesions found in the Axillary region
-Acanthosis nigricans
-Atopic Dermatitis
-Malassezia dermatitis
Com'n Lesions found on the Back
-Atopic dermatitis
-Bacterial folliculitis
-Flea bite hypersensitivity
-Schnauzer comedo syndrome
-Seborrhea, primary
Com'n Lesions found on the trunk
-Bacterial folliculitis
-Sebaceous adenitis
Com'n Lesions found on the Abdomen
-Atopy, feline
-Eosinophilic plaque
-Psychogenic alopecia
-Solar dermatitis
-Contact dermatitis
-Atypical mycobacteriosis
-Pelodera derematitis
Com'n Lesions found on the tail
-Anal sac dz
-Food intolerance
Com'n Lesions found on the Legs
-Acral lick dermatitis
Com'n Lesions found on the Paws
-Adverse food reaction
-Foreign body
-Malassezia dermatitis
-Pemphigus foliaceus
-Plasma cell pododermatitis
-Contact dermatitis
-Superficial necrolytic dermatitis (NME)
Com'n Lesions found on/near the Claws
-Lupoid onychodystrophy
-Bacterial paronychia
-Systemic lupus erythematosus
-Pemphigus foliaceus
Superficial Skin Scraping
Performed over large area, collecting abundant material
-Taken from intact, crusted lesions of p's suspected of having Sarcoptes
-Elbows, chest, pinna margins com'n areas
Dermanyssus gallinae
(Poultry mites)
May be collected w/ superficial skin scrapings
Tend to be very scarce
Scrape near excoriated sites
Acetate tape impressions may be used
Lynxacarus radovsky
(Feline Fur mite?)
Attach to hairs over spine
-Dx via Trichography
Deep skin scrapings
Taken most often when there is a suspicion of demodicosis
-Shar Pei's, particularly deep scrapings needed
Pelodera strongyloides
Free living nematode may invade skin of dogs
-600um larvae seen w/ deep skin scrapings
Direct examination of plucked hairs
If ringworm suspected, KOH clearing of keratin may help
Trichography especially useful when:
-Demodex suspected in difficult area to scrape
-Cat fur mites
Increased number of Hairs in Anagen:
Suggests an endocrinopathy or follicular arrest
Skin surface cytology types
Direct impression
Acetate Tape impression
Cotton tipped-swab
Acetate tape impression
Tape pressed against dry skin, mounted on a slide, then stained w/ blue part of diff-Quik stain
Bacterial culture and susceptibility testing indicated in:
-Cases responding poorly to appropriate antimicrobial therapy
-Suspected deep Pyoderma
-Cases when resistant or uncom'n org's are suspected d/t chronicity or unusual presentations (atypical mycobacteria, Pseudomonas, Nocardia)
Abx in regard to C/S
Should be d/c 48-72 hrs prior to culture
Deep skin infections best cultured via:
Best cultured using a skin biopsy, external surface of sample is excised and discarded
-Let lab know that you want it minced and if a special media is needed
Dermatophyte Test Media (DTM)
Contains Abx, an antifungal, and a pH indicator (phenol red- selectively metabolize available proteins before carbs, producing alkali metabolites and turning the media red)
3 most com'n spp of dermatophytes in SA's
-#1- Microsporum canis
-Microsporum gypseum
-Trichophyton mentagrophytes
Wood's Light Examination
Emits 253.7nm UV light reacting w/ tryprophan metabolites in some spp to emit a yellow-green fluorescence
-Hairs should be exposed for 3-5 minutes
Skin biopsy indicated when:
1) Have lesions suspicious of neoplasia
2) Have lesions consistent w/ a dz which is most readily dx'd by biopsy
3) Display an unusual presentation
4) Have a poor response to therapy
5) Might require long-term and/or expensive therapy
-Be able to recognize a M. canis macroconidia
-Trichophyton mentagrophytes are cream-colored colonies, powdery to granular, microconidia usually round, macroconidia cigar shaped, may have spiral shaped hyphae
Objectives Lect. 2
1. Be able to describe and provide examples of resident and transient bacteria of dogs and cats.
2. Describe the therapeutic approach for acute moist dermatitis.
3. Know the factors which may adversely affect the response of a skin infection to antibiotic therapy.
4. Be able to compare acute moist dermatitis with pyotraumatic folliculitis and furunculosis.
5. Understand the causes and therapeutic options for acral lick dermatitis.
6. Describe the typical clinical presentation of feline opportunistic mycobacterial infection.
Defense Mechanisms of normal skin
Physical (hair, s. corneum)
Chemical (sebum, sweat)
Microbial (competition for niches, antimicrobial substances)
Resident Bact of dogs
#1- S. intermedius
Clostridium spp
Propionibacterium acnes
Actinobacter spp
Micrococcus spp
Transient bact of dogs
E. coli
Proteus mirabilis
Corynebacteria spp
Bacillus spp
Pseudomonas spp
Transient flora of cats
B-hemolytic strep
E. coli
P. mirabilis
Pseudomonas spp
Bacillus spp
Topical Antimicrobials
Chlorhexidine, providone-iodine (careful w/ cats), ethyl lactate, benzoyl peroxide (best ABx topical tx), Abx
Most com'n Abx used for skin infxns
*know mech's of axn*
Cephalexin (80% of time for pyoderma)
Cefpodoxime (simplicef)

Should be given w/ systemic abx tx until pyoderma resolved
Staphage Lysate: S. aureus phage lysate for SC injection.
ImmunoRegulin: killed Propionibacterium acnes preparation for IV injection.
Autogenous staphylococcal bacterins: not widely used.
Levamisole: 2.2 mg/kg q. 48 hrs.
Cimetidine: 10 mg/kg TID.
IFN-α: human recombinant form has been used at 1-3 million IU/dog po or sc q. 1-3 days.
Superficial Bact Infxns
-Acute moist Dermatitis
-Mucocutaneous pyoderma
-Superficial bact folliculitis
Deep Bact Infxns
-Pyotraumatic folliculitis and furunculosis
-Bacterial folliculitis and furunculosis
-Nasal folliculitis and furunculosis
-Muzzle folliculitis and furunculosis
-Interdigital pyoderma
-GSD Pyoderma
-Acral lick dermatitis & furunculosis
-Subcutaneous abscesses
-Bact pseudomycetoma
-Opportunistic mycobacterial granuloma
Acute Moist Dermatitis- General info
-AKA Hot spot, Pyotraumatic dermatitis (PTD)
-Uncom'n in cats
Acute Moist Dermatitis- Etiopathogenesis
-Dvlp in minutes/hours in response to focused self-trauma
-Most often 2ndary to FAD, but many other causes
Acute Moist Dermatitis- Therapy
-Clip/Clean wound
-Non-steroid antipruritic spray (lidocaine, oatmeal)
-Topical corticosteroid/Abx spray (gentamycin/betamethasone)
-Oral pred
-Abx for 14-21 days
Impetigo- General info
Puppy pyoderma and bullous impetigo represent 2 subtypes
-NOT contagious
Impetigo- Etiopathogenesis (puppy form)
-Coagulase positive Staph. spp cultured from pustules
-May occur in assoc w/ parasitism, poor nutrition, or poor sanitary condtns, or sporadically in healthy dogs
Bullous Impetigo- Etiopathogenesis
Occurs secondary to immunosuppressive conditions such as Cushing's, hypothyroidism, and diabetes mellitus
-Staph, Pseudomonas may be involved
Impetigo- Signalment
2-12 mos (puppy pyoderma)
Middle age+ (bullous)
Impetigo-Clinical presentation
-Non-follicular pustules in the abdominal and axillary skin
-Usually non-pruritic
-Ruptured pustules dvlp into crust and epidermal collarettes
Impetigo- Therapy
-Topical Abx ointment (mupirocin)
-Abx shampoo (chlorhex, benzoyl peroxide products)
-Systemic abx if severe
Mucocutaneous Pyoderma- general
Mucocutaneous Pyoderma- Etiopathogenesis
Mucocutaneous Pyoderma- Signalment
GSD's predisposed, but may occur in any breed/age/sex
Mucocutaneous Pyoderma- Cx
-Scale, erythema, and swelling initially
-Lip commisures and wings of nostril most com'nl affected
-Lesions progress to painful crusts, exudate, and depigmentation
Mucocutaneous Pyoderma- Dx
Clinical recognition
Skin biopsy
Response to therapy
Mucocutaneous Pyoderma- Tx
-Topical abx
-Systemic abx 3-6 wks
Superficial Bacterial Folliculitis- general
AKA Staph folliculitis
Com'n in dogs (short hair > long hair)
Superficial bacterial folliculitis- Etiopathogenesis
-S. intermedius in most cases
-2y to demodicosis, irritant contact derm, atopic derm, FAD
Superficial bacterial folliculitis- Signalment
More com'n in short-haired breeds
Superficial bacterial folliculitis- Cx
-Variably pruritic
-Follicular papules, pustules
-Elevated tufts resemble hives
-Multifocal alopecia
Superficial bacterial folliculitis- Dx
-Clinical recognition of Cx
-R/O demodex and dermatophytosis
-Cytology--> PMN's and cocci
Superficial bacterial folliculitis- Tx
-Tx signs or work up underlying condtns
-Abx shampoo 1-2/wk
**Systemic abx for min. 3 wks
Dermatophilosis- General
AKA Cutaneous Steptotrichosis
-Very rare in SA's
Dermatophilosis- Etiopathogenesis
Dermatophilus congolensis
-Aerobic, Gram +
-Flagellaed, motile zoospores
-Does NOT penetrate intact skin
-Diplococci "railroad tracts"
Dermatophilosis- Cx
-Papules and coalescing circular crusts
-Crusts are adherent, yellow, incorporate hair
-Cats abscess more often
Dermatophilosis- Dx, Dogs
-Crusts minced in water, stained w/ Wright-Giemsa
-Orthokeratotic and Parakeratotic
Dermatophilosis- Dx Cats
Biopsy and histopath of nodule is the method of choice
Dermatophilosis- Tx, Dogs
Abx Shampoo and crust removal
-Penicillin V 14-21 days
Pyotraumatic folliculitis and furunculosis- General
-Hot spot
- Pyotraumatic Dermatitis (PTD)
Pyotraumatic Folliculitis and Furunculosis- Cx
-Eroded to ulcerated, alopecic, erythematous, purulent macules
-Pruritis and pain
-Com'n on cheek and neck
Pyotraumatic Folliculitis and Furunculosis- Dx
-Cx signs
-Skin biopsy
Pyotraumatic Folliculitis and Furunculosis- Tx
-Same as hot spot tx
-More resistant to tx
-Continue Abx 14d past Cx
-Discontinue pred ASAP
Bacterial Folliculitis and Furunculosis- General
-AKA Deep folliculitis, furunculosis, cellulitis
-May be assoc. w/ systemic illness
-Com'n in dog, rare in cat
Bacterial Folliculitis and Furunculosis- Etiopathogenesis
**S. intermedius most com'n
-Pseudomonas, Proteus, E. coli more com'n in deep than superficial
-Secondary to demodecosis, dermatophytosis, immunosuppression
Bacterial Folliculitis and Furunculosis- Cx
Lesions localized or generalized
-papules, pustules, hemorrhagic bullae, sinuses, nodules, etc
Bacterial Folliculitis and Furunculosis- Dx
-By Cx, may be febrile
-Cyto. exam to see bacteria and rule out fungal
-Tissue eosinophilia com'n
Bacterial Folliculitis and Furunculosis- Tx
-Severe cases may require IV fluids and parenteral Abx
-Frequent bathing w/ Abx shampoo
-Tx 2-3 wks past cure, Often 6-12 wks
Nasal Folliculitis and Furunculosis- General
AKA Nasal pyoderma
S. intermedius most com'n
Nasal Folliculitis and Furunculosis- Cx
-Painful papules/pustules on dorsal muzzle
-Rapidly progressive
Nasal Folliculitis and Furunculosis- Ddx
-Pemphigus foliaceus, discoid lupus erythematosus, eosinophilic folliculitis and furunculosis, demodecosis, Dermatophytosis
Nasal Folliculitis and Furunculosis- Tx
-Abx for 7-14d post-cure
-Soak and clean lesions TID w/ Chlorhex or Burrow's solt'n
Muzzle folliculitis and furunculosis- General
AKA- Canine Acne
Muzzle Folliculitis and Furunculosis- Etiopathogenesis
-Probably 2ndry infxn of a sterile process
-Underlying etio may be a genetic keratinization disorder aggravated by local trauma
Muzzle Folliculitis and Furunculosis- Signalment
-Young dogs
-Short-haired breeds
Muzzle Folliculitis and Furunculosis- Cx
-Early papules are sterile follicular papules around the lips and on the chin
-Chronic-- lg bleeding/oozing pustues dvlp
Muzzle Folliculitis and Furunculosis- Tx
-Modify behavior which predispose chin to trauma, if possible
-Mild cases may respond to regular Antibact cleaning/topical Abx
-Infected- ORal abx for 4-6wks
Interdigital Pyoderma- General
-AKA pododermatitis, pedal folliculitis/furunculosis
Bacterial Folliculitis and Furunculosis- General
-AKA Deep folliculitis, furunculosis, cellulitis
-May be assoc. w/ systemic illness
-Com'n in dog, rare in cat
Bacterial Folliculitis and Furunculosis- Etiopathogenesis
**S. intermedius most com'n
-Pseudomonas, Proteus, E. coli more com'n in deep than superficial
-Secondary to demodecosis, dermatophytosis, immunosuppression
Bacterial Folliculitis and Furunculosis- Cx
Lesions localized or generalized
-papules, pustules, hemorrhagic bullae, sinuses, nodules, etc
Bacterial Folliculitis and Furunculosis- Dx
-By Cx, may be febrile
-Cyto. exam to see bacteria and rule out fungal
-Tissue eosinophilia com'n
Bacterial Folliculitis and Furunculosis- Tx
-Severe cases may require IV fluids and parenteral Abx
-Frequent bathing w/ Abx shampoo
-Tx 2-3 wks past cure, Often 6-12 wks
Interdigital Pyoderma- Etiology
-Primary or idiopathic
-S. intermedius most com'n, but G - orgs may be involved and more resistant to Tx
-One foot--> FB's (awns), trauma, ostiomyelitis, fungal
-Multiple feet--> Hypothyroidism, Demodecosis, Atopy, food allerg., immunodef, hookworms, Pelodera, FB's
Interdigital Pyoderma- Dx
-Rule out underlying causes w/ skin scraping, fungal culture, skin biopsy, FB exploration, Radiography
Interdigital Pyoderma- Tx
-Tx w/ syst ABX for 6-8wks or 2 wks past clinical resolution
-Topical Abx/chorhex may help
-Chronic cases may me difficult to tx and require debridement, and or fusion podoplasty
GSD Pyoderma- General
-Hereditable dz of GSD's
-Underlying immunodeficiency
-Results in inflamm that is out of proportion to the underlying cause
GSD Pyoderma- Cx
-Rump, thighs, back, ventral abd, chest most affected
-Papules, pustules--> crusts, ulcers, fistulae
GSD Pyoderma- Tx
-Tx underlying dz if ID'd
-Clip and clean matted/ulcerated lesions
**Systemic ABX for 8-12 wks
-ABX shampoo
-Chronic ABX Tx may be needed
Acral lick Dermatitis and furunculosis- General
AKA- Lick Granuloma
-Chronic lesions carry poor prognosis for resolution
Acral lick Dermatitis and furunculosis- Etiology
-Single lesions = Boredom, local trauma, jt pain
-Multiple lesions = Atopic derm or hypothyroidism
-Often 2ndrly infected w/ Stapylococcus/other bact
Acral lick Dermatitis and furunculosis- Signalment
-Lg Breeds
-Middle age to old dogs
Acral lick Dermatitis and furunculosis- Tx
** Long term Tx, 6-12wks ABX
-Behavior modification
-Amytriptyline, fluoxetine, CLOMIPRAMINE, variable efficacy
-No single modality works in most cases
SQ Abscesses- General
-Frequent in cats, uncom'n in dogs
SQ Abscesses- Etiology
-Bite wounds (Pasturella multocida)
-Non-healing may result from immunosup, Y. pestis, mycobacterial infxn, Actinomyces, Nocardia spp
SQ Abscesses- Dx
Cx w/ evidence of skin puncture is characteristic
**serology to check FeLV/FIV status**
Bacterial pseudomycetoma- General
-AKA Botryomycosis, cutan. bact. granuloma
Bacterial pseudomycetoma- Etiology
-2ndry to penetrating wound most com'n
-Staph most com'n
-Pseudomonas, Proteus, Strep, Actinobacillus less com'n
Bacterial pseudomycetoma- Cx
Single/multiple nodules w/ draining fistulae
Bacterial pseudomycetoma- Dx
Skin biopsy
Histopath shows granulomatous to pyogranulomatous inflammation surrounding tissue granules composed of bact and eosinophilic material
-Bact C & S
Bacterial pseudomycetoma- Tx
-Surgical excision
-Systemic ABX
Opportunistic Mycobacterial Granuloma- General
-AKA= Atypical mycobacterial granuloma
-Uncom'n in cats
-Rare in dogs
-Guarded prognosis
Opportunistic Mycobacterial Granuloma- Etiology
-Facultative pathogens found in soil
-Ubiquitous organisms (Mycobact. fortuitum, M. chelonei, M. phlei, M. smegmatis)
Opportunistic Mycobacterial Granuloma- Cx
-SQ nodules, ulcers, draining tracts and fistulae
-Most com'n location is the inguinal rgn in cats
-Dogs--> nodules on pinnae
Opportunistic mycobacterial granuloma- Dx
-Demonstrate acid fast orgs
-C & S= alert lab of your suspicion, difficult to grow
Opportunistic mycobacterial granuloma- Tx
-Surgical excision when practical
-Enrofloxacin, Doxycycline
**Months of tx usually necessary (4-6wks past clinical cure)
Plague- General
-Cats/rodents much more susceptible
-30-40 spp of wild rodents as natural reservoirs
-Transmitted b/t rodents/fleas
-Bubonic, pneumonic, septicemic forms
Plague- Etiology
-Yersinia pestis
-G Neg, fac anaerob, nonmotile, bipolar staining coccobacillus
-Rocky mtn states and Hawaii
Opportunistic Mycobacterial Granuloma- General
-AKA= Atypical mycobacterial granuloma
-Uncom'n in cats
-Rare in dogs
-Guarded prognosis
Plague- Cx
-Febrile (105-106F)
-Submand, retropharyng, cervical LN's abscess and drain (bubo formation)
-Bubonic form may progress to septicemic form and pulmonic form (least com'n)
Plague- Dx
-Cytology of exudates and aspirates: monomorphic population of Gram Neg bipolar coccobacilli
Plague- Tx
Gloves/mask should be worn
-Tx should begin BEFORE laboratory confirmation
Fungal sections Objectives
1. Be able to discuss the three species of dermatophytes which most commonly infect small animals.
2. Describe three clinical presentations of feline dermatophytosis.
3. Describe how to reach a diagnosis of Malassezia dermatitis.
4. Know the geographic distribution of the systemic mycoses.
5. Know which fungal infections carry the greatest risk of zoonosis.
Superficial Mycoses
Dermatophytosis- General
-Overdiagnosed d/t over-reliance of Wood's light examination
Dermatophytosis- Etiology
-Fungal infxn of the s. corneum, hair, and/or claw by:
-Microsporum, Trichophyton, or Epidermophyton spp.
Dermatophytosis- 3 most com'n org's
Microsporum canis
M. gypseum
T. mentagrophytes
Microsporum canis
-Most often acquired from cats
-Spindle-shaped macroconidia w/ thick walls and 6+ cells
-White to buff, cottony colony
Microsporum gypseum
-Most often acquired from soil
-Ellipsoidal macroconidia w/ THIN walls and 4-6 cells
-Beige, granular colonies
Trichophyton mentagrophytes
-Most often acquired from rodents or enviro
-Numerous grape-like clusters of microconidia, few cigar-shaped macroconidia, spiral hyphae
-White to cream, powdery to granular colony
Dermatophytosis- signamlent
-Long haired cats
-Yorkies, dalmatians
-Poor nutrition, immunosuppressed at incr risk
Miliary Dermatitis
Characterized by multiple, small, crusted papules and pruritis
-RARELY caused by M. canis, much more com'n from Flea allergies
Dermatophytosis- Cx- Dogs
-Annular lesions w/ alopecia, follicular papules, scale and crust most com'n
-Folliculitis, furunculosis and scarring alopecia seen w/ T. mentagrophytes
Nodule w/ purulent exudate
Dermatophytosis- Dx
-Wood's Light
-Trichography (ectothrix spores)
-Skin biopsy (not as sensitive as DTM)
Dermatophytosis- Tx
-Environmental deconamination
-spores viable for 18mos
-1:10 or 1:20 bleach
-Destroy Bedding/grooming aids
-Topical-- CLOTRIMAZOLE, miconazole, terbinafine
-Shampoos--chlorhex, miconazole
-Rinses-- Lime sulfur
-Microsized (Fulvicin U/F)
-Ultramicrosixed (Gris-PEG)
Malassezia Dermatitis- General
-Yeast dermatitis
-Com'n in dogs, rare in cats
Malassezia Dermatitis- Etiology
M. pachydermatis (syn Pityrosporum canis)is a normal inhabitant of K9 skin/ears
-Other factors may predispose to overgrowth, various dermatites, FAD, etc
Malassezia Dermatitis- Cx
-Generalized or regional
-Lichenification and hyperpigmentation if chronic
-Paronychia and claw infxns w/ brown discoloration and waxy accum on claws and nail biting
Malassezia Dermatitis- Dx
Skin surface cytology
-Direct impression
-Acetate tape impression
-Cotton-tipped swab
Skin biopsy less sensitive b/c outer half of s. corneum lost during processing
Malassezia Dermatitis- Topical Tx
Ointments: Clotrimazole, miconazole, terbinafine
Shampoos and rinses: Chlorhex, miconazole
Malassezia Dermatitis- Systemic Tx
Itraconazole, fluconazole
***Griseofulvin is NOT effective***
Candidiasis- General
AKA- Moniliasis, Thrush
-Normal inhabitants of alimentary, upper resp, genital mucosa
Candidiasis- Signalment
-Dogs w/ Diabetes mellitus, Cushing's, Hypothyroidism, neoplasia, taking immunosuppressive drugs
Candidiasis- Cx
-Grey plaques/ulcers in mucocutaneous jxns, ear canal, intertriginous areas, interdigital areas
-Papular to pustular lesions
Candidiasis- Dx
-Cutaneous cytology
-Narrow-based budding org's
Candidiasis- Tx
-Correct underlying dz
-Control moisture by clipping and cleaning, when approp.
-Topical antifungals
-Systemic antifungals
Subcutaneous Mycoses
-Often introduced via trauma, grow in living tissue
-Eumycotic mycetoma
Eumycotic mycetoma- General
-Tropical dz
-Rare in US
Eumycotic mycetoma- Etiology
-Most com'nly caused by Pseudoallescheria boydii
-Gains entry via wound contamination
Eumycotic mycetoma- Cx
-Solitary nodules, draining tracts and tissue grains
-Head/limbs most affected
Eumycotic mycetoma- Dx
Fungal culture
Eumycotic mycetoma- Tx
-Surgical excision or limb amputation
-Poor prognosis
Phaeohyphomycosis- General
-AKA Chromomycosis
-Pigmented hyphae
Phaeohyphomycosis- Etiology
-Many dematiaceous soil saprophytes are capable of causing this
-Bipolaris spiciferum
-Xylohypha bantiana
Phaeohyphomycosis- Dx
Cytology and histopath
-Granulomatous to pyogranulomatous dermatitis and panniculitis
Phaeohyphomycosis- Tx
-Poor prognosis w/ recurrence com'n
-Amphotercin B
-Wide surgical excision
Zygomycosis- General
-Mucormycosis, entomopthoromycosis
Zygomycosis- Etiology
-RARE in dogs & cats
-Multiple fungi cause this
-Rhizopus, Mucor, Absidia, Conidiobolus, Basidiobolus
Zygomycosis- Cx
-Solitary or multiple ulcerated, draining nodules on extremities
Zygomycosis- Tx
-Surgical excision or debulking along w/ antifungal therapy
Sporotrichosis- General
-Exudates and tissues from cats are infective
Sporotrichosis- Etiology
-Sporothrix schenckii
-Mycelial form in environment, yeast form in tissue
-Gains entry via wound
-Dogs- splinters and thorns
-Cats- Contaminated claws
Sporotrichosis- Cx
-Cutaneous, cutaneolymphatic, disseminated froms may occur concurrently
-Lesions begin distally and travel up
-Cats dvlp abscesses and cellulitis under puncture wound
-Dissemination often evident at necropsy
Sporotrichosis- Dx
**Suspect this dz when an abscess or wound responds poorly to tx**
-Fluorescent Ab testing
Sporotrichosis- Tx- Dogs
-Supersaturated solution of potassium iodide (SSKI) is the tx of choice
-If iodism is a concern, use ketoconazole or itraconazole
Sporotrichosis- Tx- Cats
Itraconazole is Tx of choice since cats are more susceptible to SSKI and Ketoconazole SE's
-Monitor for hepatotoxicity, anorexia, vomiting, wt. loss
Rhinosporidiosis- General
RARE in dogs
NOT reported in cats
Rhinosporidiosis- Etiology
Rhinosporidium seeberi
Difficult to culture
Mucous Mb trauma may predispose to infxn
Rhinosporidiosis- Tx
Surgicl excision of polyps is often curative
-Dapsone or Ketoconazole may help w/ recurrence
Systemic Mycoses (Cutaneous manifestations)
Hematogenous and lymphatic spread of deep or systemic mycoses may lead to skin infxn
Primary cutaneous infxn is extremely rare
Blastomycosis- General
UNCOMMON in dogs
VERY RARE in cats
-MS, OH, MO river valleys
-NOT zoonotic by aerosol from infected pets, but humans have gotten infected at the same time as pets
Blastomycosis- Etiology
Blastomyces dermatitidis, a dimorphic saprophyte
-Inhalation of spores from mycelial growth in enviro
**Infection established in the lungs**
Blastomycosis- Signalment
1-5 yo, male, outdoor, hunting dogs most com'nly affected
Blastomycosis- Cx
-Skin lesions in 20-40% of infected dogs
-Planum nasale, face, and nail beds most com'n sites
-Papules, plaques, nodules, ulcers, draining tracts, abscesses
-Multi-system involvement:
fever, dry harsh lung sounds, ocular lesions, lameness and bone involvement, wt loss
Blastomycosis- Dx
-Cytology of exudates shows round to oval yeast
-Fungal culture
-Radiograph chest, and lame limbs
Blastomycosis- Tx
-Itraconazole Tx of choice**
-Amphotericin B and Ketoconazole alternatives
-Fair prognosis if no brain involvement or bad lung dz
Coccidiodomycosis- General
-San Joaquin Valley Fever
-Valley Fever
-UNCOM'N (dogs) to RARE (cats)
-Southwestern US
Coccidiodomycosis- Etiology
Coccidiodes immitis, a soil-borne fungus
-Epidemics may follow wind, recent rain, or earthquakes
-Inhalation of arthroconidia
-Most asymptomatic
Coccidiodomycosis- Signalment
1-4 yo male dogs predisposed
Coccidiodomycosis- Cx
-Multi-system involvement:
fever, anorexia, wt. loss, depression
-Skin lesions 2ndry to disseminated dz
**Papules, nodules, ulcers and draining tracts usually over site of infxn in DISTAL long bone**
Coccidiodomycosis- Dx
Cytology and histology may work, but not com'nly
-Dx based on clinical signs, radiograph findings, and serology
-Fungal culture should be avoided
Coccidiodomycosis- Tx
Guarded prognosis w/ frequent relapses
-Ketoconazole, itraconazole, fluconazole, Amphotericin B
Cryptococcosis- General
-RARE in dogs
-UNCOMMON in cats
**Pigeon droppings serve as the main reservoir**
-NOT Zoonotic
Cryptococcosis- Etiology
Cryptococcus neoformans is a ubiquitous, saprophytic, round, yeast-like fungus
-Forms a capsule when growing in tissue, hindering Ag presentation
-Rte of infxn--Inhalation
Cryptococcosis- Signalment
-Siamese cats susceptible
-In dogs, young adults
-Doberman, Great Danes, American Cockers
Cryptococcosis- Cx
-Skin lesions in 40% of cats, 20% of dogs
-Nasal cavity involved in 80% of cats (polyps)
-Papules, nodules, ulcers, draining tracts
-Other signs: CNS, ocular, wt loss, mild fever
Cryptococcosis- Dx
-Cytology of nasal exudates, skin exudates, CSF, tissue impressions
-Fungal culture, histopath, serology
Cryptococcosis- Tx
-Long term tx - 7-10 mos
-Serial latex agglutination testing help to monitor response
-ITRACONAZOLE drug of choice
-Fluconazole for CNS involvement
-Ketoconazole- Use w/ CAUTION w/ cats
-Amphotericin B and Flucytosine used less com'nly d/t toxicity
Histoplasmosis- Etiology
Histoplasma capsulatum
-Survives best in soils w/ bat and bird excrement
-Inhalation probable route of inoculation
Histoplasmosis- General
UNCOMMON in dogs/cats
-Most cases in MI, MO, OH River valleys
Histoplasmosis- Signalment
-Young cats and dogs (<4yo)
-Pointers, Weim's, Brittany spaniels
Histoplasmosis- Cx
-Disseminated dz most com'n
-Skin infrequently affected
-Papules, nodules, ulcers, tracts
-Usually multiple lesions
-Face, nose, pinnae
-Depression, wt loss, anorexia, dyspnea
-Dogs--> Lg bowel diarrhea
Histoplasmosis- Dx
-Org's usually numerous in exudates and tissues
-Intracellular small, round yeast in mononuclear cells
-Basophilic center and light halo caused by shrinkage
-Fungal culture should be avoided (let the pro's do it)
-Serology unreliable
Histoplasmosis- Tx
-Fluconazole (CNS)
-Ketoconazole less effective
Parasitic Skin Diseases I: Mites, Helminths, & Flies
1. Be able to describe the clinical features, diagnosis, and treatment of canine demodicosis.
2. Be able to recognize the mites affecting dogs and cats.
3. Understand why ivermectin is more toxic to certain individuals.
4. List three techniques for the collection of Cheyletiella mites.
Demodicosis- General
AKA-Follicular mange, Red mange
-Com'n in dogs
-RARE in cats
Demodicosis- Etiology in Dogs
-Demodex canis
-Normal resident of skin
-Juvenile onset assoc. w/ immune abnormalities and genetics
-Adult onset assoc. w/ Immuosuppression, metabolic dz, neoplasia
Demodicosis- Etiology in Cats
Demodex cati assoc'd w/ systemic dz (FIV, FeLV, diabetes mellitus, SLE)
-Plumper mite
Localized Demodicosis
-5 or less discrete lesions
-Periocular, perioral, limbs most com'nly affected
-Mild erythema, alopecia
Generalized Demodicosis
>5 patches, lg rgns, or generalized
-Any rgn of the body, esp feet
-Mild-severe erythema, alopecia
-Swelling, sinus tracts may dvlp
-May dvlp deep bact folliculitis/furunculosis
-Greasy and malodorous
Felin Demodicosis
-Periocular, head, neck alopecia
-Erythema, scale, crust
-Ceruminous otitis externa
-Pruritis variable, severe w/ D. gatoi
Demodicosis- Tx- dogs
-Localized, should resolve w/o tx
-Topical benzoyl peroxide gel or rotenone
-Repeat monthly skin scapings until 2 negatives
-Amitraz (Mitaban)- *ONLY approved tx
-Don't bathe b/t dips
-Milbemcyin (Interceptor)
Demodicosis- Tx- cats
-Often self-limiting
-Weekly lime-sulfur dips for 4 wks if generalized or D. gatoi
Canine Scabies- Etiology
-S. scabiei var. canis
-Front legs short w/ UNJOINTED pedicles and suckers
-Burrow in the s. corneum
Canine Scabies- Cx
-Pruritis severy by 3-4wks
-Positive pinnal-pedal reflex
-Ventral chest, abdomen, legs, elbows, pinnal margins
-Papules, alopecia and erythematous, excoriated crusted macules
Canine Scabies- Dx
-Superficial skin scrapings positive less than 50% of time
-When scabies suspected, but not seen, trial tx w/ Revolution
-Skin scrapings over large areas
Canine Scabies- Tx
**Tx ALL dogs in house**
-Selamectin (Revolution) every 2 wks for 3-4 tx's
-Ivermectin SQ wkly for 3-4wks
-Lime-sulfur dips
-In many cases the pruritis will worsen at first, by 14d improvement should be seen
Notoedric Mange- General
-AKA Feline scabies, Head mange
-HIGHLY contagious
Notoedric Mange- Etiology
-Notoedres cati (a sarcoptiform mite)
-Smaller than sarcoptes, look similar, w/ dorsal anus
Notoedric Mange- Cx
-Pinnae, face, neck, legs, feet, perineum mostly affected
Notoedric Mange- Dx
Skin scrapings reveal mites w/ UNJOINTED pedicles (shorter than sarcoptes) w/ suckers
Notoedric Mange- Tx
Ivermectin a good alternative
Cheyletiellosis- General
"Walking Dandruff"
-Dogs, cats, rabbits
Cheyletiellosis- Etiology
Dogs- C. yasguri
Cats- C. blakei
Rabbits- C. parasitivorax
Cheyletiellosis- Cx
-Pruritis varies from non-existent to severe
-Dorsal distribution of scaling
-May be asymptomatic
Cheyletiellosis- Dx
-Acetate tape impression
-Superficial skin scraping
-Fecal exam
Cheyletiellosis- Tx
-Selamectin once monthly
-Ivermectin every 2wks
-Milbemycin weekly (9X)
-Lime Sulfur dips wkly
Trombiculosis- General
-Chiggers, Harvest mites
-Most of time spent off patient
Trombiculosis- Etiology
-Eutrombicula alfreddugesi
-Neotrombicula autumnalis
-Walchia americana
Larvae feed on animals
Trombiculosis- Cx
-Lesions in areas w/ contact to ground: feet, head, ears, ventrum
-Intensely pruritic
Trombiculosis- Dx
Trombiculosis- Tx
Fipronil spray
Dermanyssus gallinae- General
-Poultry mite, red mite
-Rarely affects dogs and cats
-May affect pets w/ access to poultry
Dermanyssus gallinae- Tx
-Pyrethrin shampoo
-Revolution likely as effective
-Environmental decontamination
Lynxacarus radovsky- General
-Cat fur mite
-AUS, HI, Brazil
-Not very contagious
Lynxacarus radovsky- Tx
-Lime sulfur dips
Otodectes cynotis- General
-Ear mite
-Non-burrowing mite
-3wk life cycle
Highly contagious
Otodectes cynotis- Tx
-Otic preparations
Pelodera- General
-Rhabditic dermatitis
-Uncom'n in dogs
Pelodera- Etiology
-Pelodera strongyloides
-Aberrant infestation w/ larval stage of a free-living nematode found in organic material (Straw)
Pelodera- Cx
-Pruritis of the ventral chest and abdomen, feet, legs
-Erythematous and alopecic skin dvlping papules, pustules
Pelodera- Dx
-Skin Scrapings
-Skin biopsy
Pelodera- Tx
-Remove infected bedding
-Tx environment w/ insecticide
-Self-limiting when bedding replaced
Hookworm Dermatitis- General
-Uncom'n in dogs, rare in cats
-Spring/Summer most com'n
Hookworm Dermatitis- Etiology
Uncinaria stenocephala most com'n
-3rd stage larvae enter skin
Fly Bite Dermatitis- Etiology
-Stomoxys calcitrans (stable fly)
-Simulidae spp (black flies)
Fly Bite Dermatitis- Cx
-Highest pt of ears most com'nly bit by stable flies
-Hairless/thin areas bitten by black flies
Fly Bite Dermatitis- Tx
Fly control measures
-Repellants (permethrin, citronella)
-Clean enviro
-Topical Abx/steroids
-Bees, wasps, hornets
-Eosinophilic folliculitis and furunculosis of the face
Fire Ants
Solenopsis invicta
-1-2 cm wheals
Fleas vectors for:
Transmit Rickettsia, Bartonella, Dipylidium
Echidnophaga gallinacea
Poultry sticktight flea
Spilopsyllus cuniculi
Rabbit flea
Flea Bite Hypersensitivity- General
Type I Hypersensitivity rxn
Cutaneous basophil hypersensitivity
Flea control- Adulticides
-Fipronil (Top spot, frontline Plus)
-Imidacloprid (Advantage)
-Selamectin (Revolution)
-Nitenpyram (Capstar)
--other traditional insecticides
-Blocks GABA-gated Cl channel in insects
-Blocks nicotinic receptors of postsynaptic neurons
-Semisynthetic avermectin
-GABA interaxn, increases Cl permeability
-Binds nicotin receptors
Insect Growth Regulators
-Lufenuron (Program)
-Methoprene (Frontline Plus)
Fleas- Antipruritic therapy
-Trimepramine/Pred (Temaril-P)
Pediculosis- General
-Lice infestation
-Dorsoventrally flattened
-Entire life on host
-Nits on hair shaft
-14-21 d life cycle
-May be more com'n during winter
Sucking Lice
-Linognathus setosus (dogs)
Biting lice
-Trichodectes canis
-Felicola subrostrata
-Heterodoxus spiniger (dogs)
Ticks- Common species
-Rhipicephalus sanguineous (brown dog tick)
-Dermacenter variabilis (American dog tick- rectangular basis capituli)
-Ixodes Pacificus (Western black-legged tick)
Ticks- Tx
-Tick removal, soak w/ alcohol and apply steady traction
-Amitraz collars (Preventic)
-Methoprene, permethrin (dogs)
-Premise tx w/ chlorpyrifos
Atopic Dermatitis- Objectives
1. Be able to describe the difference between extrinsic atopic dermatitis and intrinsic atopic dermatitis.
2. Learn some of the breeds that are predisposed to atopic dermatitis.
3. Be able to describe how you would make a diagnosis of atopic dermatitis.
4. Understand the limitations intradermal testing, serum allergy testing, and immunotherapy.
5. Be able to describe how you would manage a dog with mild, seasonal atopic dermatitis versus one with severe, year-around atopic dermatitis.
6. Know the indications and potential side effects of cyclosporine A therapy.
Atopic Dermatitis- General
AKA- Allergic inhalant dermatitis, airborne allergies
-Dogs > Cats
-3-15% of all dogs
-Predisposed to become allergic to normally innocuous substances
Atopic Dermatitis- Etiology
-Immunologic response not well understood
-Type I HS rxn
-Animal becomes sensitized to allergen-specific IgE, which binds to receptor sites on cutaneous mast cells, further allergen exposure causes mast cell degranulation (d/t IgE x-linking)and results in release of histamine, tryptase, chymase, leukotrienes, TNF-a
Atopic Dermatitis- Pathogenesis may also include:
-Epidermal lipid barrier defect allowing percutaneous absorption of allergens at sites of friction and trauma
-Allergen processed by Langerhans cells and presented to allergen-specific T-cells
-Sub-class of IgE which is overabundant in atopic dogs
-Increased inflamm mediators
-Failure to down-regulate
Atopic Dermatitis- Signalment
-Familial history is com'n, although unclear how
-Any breed affected
-Shar pei, WHWT
-Onset 1-3yrs
Atopic Dermatitis- Dx
-Mild to severe pruritis
-Primary lesions may occur, but 2ndry more com'n
-Chronicity leads to salivary staining, hyperpigmentation, lichenification
Atopic Dermatitis- Com'n areas affected
-Interdigital spaces
-Carpal/tarsal areas
-Periocular rgns
Atopic Dermatitis- Dx
-A clinical Dx b/c lab testing isn't very specific or sensitive
-Seasonal pruritis
-Exclusion of FA w/ approp elimination trial
-Exlusion of FBH w/ flea ctrl
-Typical distribution
-Recurrent otitis externa
Atopic Dermatitis- Allergy Testing
-Should be used to select allergens for inclusion in immunotherapy tx, not for a dx
Drugs to withdraw prior to intradermal allergy testing
Antihistamines- 14d
Topical steroids- 14-21d
Prednisone- 4 wks
Inj. Triamcinolone- 6wks
Sedation to avoid prior to Intradermal Allergy testing
-Oxymorphone, ketamine/diazepam, acepromazine, propofol
-OTHER sedatives should be ok
Intradermal Testing (IDT) methods and results
-Inject histamine and saline for +/- controls
-Inject 0.05-0.1cc of each sol'n intradermally
-Wheal sized 0-4
-0-1 negative
-Test rxns evaluated 15mins after injxn
Serological allergen-specific IgE testing (SAT)
Does not agree well w/ IDT
-Repeatability varies
Serological allergen-specific IgE testing (SAT)--Advantages over IDT
-Sedation not required
-Less invasive
-Less concerns about drug withdrawal
Serological allergen-specific IgE testing (SAT)-- Disadvantages over IDT
-Results not immediate
- Immunotherapy less effective based on SAT results
-No control over allergen selection
Atopic Dermatitis- Tx- General
-Tx usually required for life, at least seasonally
-Tailor Tx's to signs
-Combo therapy
-Tx pyoderma or Malassezia
Atopic Dermatitis- Tx- Topical
-Fluocinonide spray (Genesis)
-Antipruritc shampoos (oatmeal, hydrocort.)
Atopic Dermatitis- Essential FA supplementation
-Best used as an adjunctive therapy
-Total dietary EFA supplementation is more significant than adding sm amts
Atopic Dermatitis- Tx- Antihistamines
-Evidence supporting efficacy is poor (10-20% of time)
Atopic Dermatitis- Tx- Glucocorticoids
-In spite of SE's, efficacy and low cost are important
-Use the least amt to control pruritis
-Break itch-scratch cycle
-Trimeprazine/prednisolone (Temaril-P)
-Pred, Prednis, Methylprednisolone EOD
-INJECTABLE: Dexamethasone (short acting) vs Methylprednisolone (long term)
Atopic Dermatitis- Cyclosporine A (Atopica)
-Lipophilic cyclic fungal polypeptide
-Microemulsion concentrate
-Low cytotoxicity vs immunosuppression
-Block CK gene transcription in activated T-cells
-Inhibits fxns of cells which initiate immune response (lymphocytes,etc)
-Inhibits fxns of effector cells (mast cells, eosinophils)
Atopic Dermatitis- Atopica SE's
Vomiting, Soft stool, diarrhea, hirsutism, gingival hyperplasia, Cutaneous papillomatosis
Atopic Dermatitis- Atopica drug interactions
-Metabolized by cytochrome P-450
-Inhibitors may increase CsA levels
Atopic Dermatitis- Miscellaneous Non-steroidal drugs
Atopic Dermatitis- Tx- Immunotherapy
~70-80% efficacy (at least 50%)
-Response is slow and gradual
-Gradually incr amts of allergens
Adverse Food Reactions, Contact Dermatitis, and Eosinophilic Granuloma Complex-- Objectives
1. Know the clinical presentation of adverse food reactions in dogs and cats.
2. Understand how to go about diagnosing an adverse food reaction.
3. Be able to describe the pathogenesis of allergic contact dermatitis.
4. Describe the clinical presentations comprising the eosinophilic granuloma complex of cats.
Adverse Food Rxns- General
-Food hypersensitivity and food intolerance
-5-15% allergic skin dz in dog/cat
Adverse Food Rxns- Etiology
-Not completely understood
-Immediate (Type I HS) or delayed (Types III & IV)
-Non-immunologic, involves effect of ingredients of food inducing histamine release
Adverse Food Rxns- Cx
-Non-seasonal pruritis
-Poorly glucocorticoid responsive
-Distribution is identical to Atopy
-Dz may be limited to ears
Adverse Food Rxns- Dx
-Neither IDT or SAT are reliable for diagnosing AFR
-Hypoallergenic diet trials w/ provacative challenge testing is most reliable method of dx
-Switch diet for 6-12wks
Contact Dermatitis- General
2 types
-Allergic contact dermatitis (ACD)
-Irritant contact dermatitis (ICD)
Adverse Food Rxns- Etiology
-Direct damage to keratinocytes by exposure to a chemical
-Immunologic rxn involving Type IV HS
-Elicitation phase occurs on subsequent exposure, Memory T-cells recruited to the area, host of CK's released w/ the end result of inflamm
Adverse Food Rxns- Tx
Eosinophilic Granuloma Complex- General
3 distinct entities in the cat:
1) Eosinophilic granuloma (linear)
2) Eosinophilic plaque
3) Indolent ulcer (lip ulcer)
COMMON in cats
RARE in dogs
Eosinophilic Granuloma Complex- Signalment
-Indolent ulcers more frequent in females
-Eosinophilic plaques- geneteic
Eosinophilic Granuloma Complex- Cx- Eosinophilic plaque
-Pruritic, alopecic, erythematous, eroded patches and plaques
-Ventral abdomen and axillae
Eosinophilic Granuloma Complex- Cx- Eosinophilic granuloma
-White to yellow plaques, nodules
-Linear lesions on cd thighs, swelling of chin, oral nodules
Eosinophilic Granuloma Complex- Cx- Indolent ulcers
-Non-painful ulcers on the upper lip, usually adjacent to philtrum
Eosinophilic Granuloma Complex- Tx
-Immunotherapy or hypoallergenic diets may be successful in those cases where a specific dx is made
Immune Mediated Skin Dz's- Objectives
1. Be able to compare and contrast the various forms of pemphigus/pemphigoid diseases.
2. Know the non-cutaneous signs of systemic lupus erythematosus.
3. Know the clinical presentations of EM and TEN.
4. Be able to describe how you would make a specific diagnosis and treat a patient with nasal depigmentation and/or crusting.
Immune Mediated Skin Dz's- General
AI dz's result from dvlpmt of Ab's or lymphocytes directed against normal body tissues
-Secondary IM dz's are those resulting from rxns to foreign substances that stim. immunologic rxns
-1-2% of all k9, feline dermatoses
Immune Mediated Skin Dz's- Hypothetical mechanisms
-Suppressor T-cell dysfxn
-X-reacting Ag's
-Abnormal MHC II expression or interaxn
Pemphigus foliaceus- General
Most com'n form of pemphigus complex
Pemphigus foliaceus- Etiology
-Primary target Ag is desmoglein I, an adhesion molecule of keratinocytes
-Auto-Ab's against desmoglein I result in loss of adhesiveness
-Subcorneal pustules containing rounded keratinocytes (ACANTHOCYTES) dvlp
-Drug-induced form should be self-limiting
Pemphigus foliaceus- Signalment
Akita, Chows, Labs, Dobies, others
Mean age of onset- 4 years
Pemphigus foliaceus- Cx
-Planum nasale, face, ears most com'nly affected in dogs
-Footpads, nail beds, areolas, most com'n in cats
-Depigmentation, crusting, erythema com'nly observed
-Pustules, erythema, alopecia
-Variable pruritis
Pemphigus foliaceus- Dx
-Cytology of pustules: PMN's and acantholytic keratinocytes
-Histopath- Subcorneal pustular dermatitis w/ acantholysis and acanthlytic keratinocytes in pustules, crusts
-Immunohistochem- Intracell Ab deposition in the s. spinosum
Pemphigus foliaceus- Tx
-#1-Prednisolone or Pred
-Triamcinolone, methylprednisolone
-Azothioprine (not in cats- BM suppression)
-Chorambucil (Leukeran) LT mgmt
-Chrysotherapy (gold salts)
-Aurothioglucose, Auranofin
Pemphigus erythematosus- General
-Poss mild form of PF
-Face and ears MOST com'nly affected
-Depigmentation on planum nasal early in dz
-May worsen w/ SUN xpsure
Pemphigus erythematosus- Cx
-Histopath features of both PF and DLE
-Subcorneal pustules w/ acanthocytes, acantholysis, Lymphocytic-plasmacytic interface dermatitis
Pemphigus erythematosus- Tx
-Sun avoidance
-Topical glucocorticoids
-Topical tacrolimus (Protopic)
-Tetracycline and niacinamide
-Oral pred
Pemphigus Vulgaris- General
RARE in dogs/cats
-Target Ag is desmoglein III, an adhesion molecule
Pemphigus Vulgaris- Cx
-Vesicles, bullae, ulcers of oral cavity/mucocutaneous jxns, groin, axillae
Pemphigus Vulgaris- Dx
-Histopath: SUPRAbasilar acantholysis, clefts, and basement mb attached basal cells appearing as "ROW OF TOMBSTONES" (deeper than PF)
Pemphigus Vulgaris- Tx
-Early and aggressive Tx warranted
-Pred and azathioprine (dogs)
-Poor prognosis
Pemphigus vegetans- General
-May represent a variant of PF
-Tx same as PF
Pemphigus vegetans- Cx
-Vesicles and pustules on verrucuous vegetations
-Variable pruritis
Bullous Pemphigoid- General
-VERY RARE in dogs/cats
-Collagen type XVII is hemidesmosome Ag apparently involved
Bullous Pemphigoid- Cx
-Vesicles, bullae, ulcers
-Looks like PF
-Vesicles tense and persistent
-2ndry pyoderma com'n
-Axillae and groin most affected
Bullous Pemphigoid- Dx
-Excisional biopsy of vesicle
-Histopath: Subepidermal cleft and vesicle formation
-DIF or IH testing reveals linear deposition of Ig's and C' at Basement mb
Bullous Pemphigoid- Tx
-Aggressive immunosuppressive Tx usually required
Discoid Lupus Erythematous- General
-AKA- DLE, Collie nose
-Com'n in dogs
-VERY RARE in cats
Discoid Lupus Erythematous- Etiology
-Aggravated by sunlight ~50% of cases
-Type III HS rxn
-Auto-Ab's to nuclear Ag's or immune complex deposition involved in lesion formation
Discoid Lupus Erythematous- Signalment
Collies, Shelties, GSD's
Discoid Lupus Erythematous- Cx
-Depigmentation and erosions early in the course of dz
-Crusting ulcerations may dvlp
-Nasal planum, nares, lips, dorsal muzzle
Discoid Lupus Erythematous- Dx
-Histopathology samples should be taken from depigmented, but non-ulcerated areas
-ANA (anti-nuclear Ab) testing is usually NEGATIVE
Discoid Lupus Erythematous- Tx
-Sun avoidance
-Tailor to severity
-Topical glucorticoids
-Topical tacrolimus
-Vit. E
-Tetracycline and niacinamide
Vesicular cutaneous lupus erythematosus- General
-Rough collies and Shelties
-Onset usually during summer
Vesicular cutaneous lupus erythematosus- Cx
-Annular and polycyclic ulcerations on the ventral abdomen, axillae, groin, pinnae
Systemic Lupus Erythematosus- General
*A multisystem AI dz of unknown etiology
-UNCOMMON in dogs
-RARE in cats
Systemic Lupus Erythematosus- Etiology
-Antinuclear and anticytoplasmic Ab's are formed
-Immune complexes deposited in glomerular basement mb, synovial mb, skin, BV's
-C'activation results in tissue injury
Systemic Lupus Erythematosus- Signalment
-Collies, Shelties, GSD's, Poodles
-Any age
Systemic Lupus Erythematosus- Cx
-Acute or insidious onset, depending on systems affected
-Shifting leg lameness
-Muscle wasting
Variable pruritis, Erythematous macules, scaling, alopecia, ulceration
-Oral and mucocut. ivolvement is com'n
Systemic Lupus Erythematosus- Dx
-Often elusive dx d/t variability of organs affected
-Recognize variable multi-system involvement signs
-Hematologic disorders
Systemic Lupus Erythematosus- Tx
-Depends upon organ system involved
-Cyclophosphamide (for anemia)
-Vincristine (for thrombocytopenia)
Uveodermatological Syndrome- General
-AKA- Vogt-Koyanagi-Harada-like syndrome (VKH)
-Rare K9 dermatitis and uveitis
Uveodermatological Syndrome- Etiology
-Unknown etiology
Uveodermatological Syndrome- Signalment
-Akitas, Chows, Husky, Samoyeds
-No sex/age discrimination
Uveodermatological Syndrome- Cx
Acute onset of uveitis: photophobia, blepharospasm, corneal edema, blindness
-Glaucoma and cataracts may dvlp
-depigmentation of nose
-Scale, erythema dvlp
Uveodermatological Syndrome- Dx
-Clinical recognition
-Histiocytic lichenoid dermatitis
Uveodermatological Syndrome- Tx
-Early dx and tx essential to avoid blindness
-Opthalmic glucocorticoids and cycloplegics (atropine)
Cutaneous adverse drug rxn- General
-May involve types I, II, III, and IV HS rxns
-Most com'n assoc: in dogs/cats: topical agents, sulfonamides, penicillins, cephalosporins
Cutaneous adverse drug rxn- Cx
-Exfoliative dermatitis
-Inj. site rxns
Cutaneous adverse drug rxn- Dx
-Suspicious Hx and Cx
-D/c suspect drug for 10-14d
Erythema multiforme- General
-Thought to be cell mediated Hypersensitivity
-May be initiated by multiple fx's
Erythema multiforme- Cx
-Acute onset
-Erythematous macules/papules
-Target lesion
-Vesicles and bullae
-Oral ulcers
-fever, depression, anorexia
Erythema multiforme-Dx
-Histopath: single-cell apoptosis of keratinocytes throughout epidermis and follicular outer root sheat
Erythema multiforme- Tx
-Correct underlying cause
-Immunosuppression may be helpful
Toxic Epidermal Necrolysis- General
-RARE, extensive skin dz assoc w/ a poor prognosis
-May be a drug rxn causing keratinocyte apoptosis
Toxic Epidermal Necrolysis- Dx
-Histopathology: basal cell hydropic degeneration, full-thickness coagulation necrosis of epidermis
Vasculitis- General
-UNCOM'N in dogs
-RARE in cats
-Thought to be a Type III HS rxn
-Number of causes
-50% idiopathic
Vasculitis- Signalment
-Jack russel, Scottie, GSD, Greyhound, Dachshund, Rotties
-Vx rxns more prevalent in poodles, Bichon, silky terriers, yorkies, Pekingese, maltese
Vasculitis- Cx
-Tip of pinnae, footpads, tail tip
-Purpura, plaques, hemorrhagic bullae, papules, pustules, necrosis
-Anorexia, depression, fever
Vasculitis- Proliferative Thrombovascular necrosis of the pinnae
-Elongated necrotic ulcer at the pinnal apex
Vasculitis- Focal cutaneous vasculitis and alopecia secondary to rabies vx
-Poodles, yorkies, silkies
-Alopecia, scarring dvlp 3-6 mos after vx
Vasculitis- Cutaneous and renal glomerular vasculopathy
-AKA Alabama Rot
-Limbs, trunk, groin
-E-coli toxin in raw beef products
Vasculitis- Familial cutaneous vasculopathy of GSD's
Puppies, fever, lethargy, swollen footpads, Alopecia, crusts
Vasculitis-Ischemic Dermatopathy
-Post-rabies vx alopecia
-Plaques, nodules, erosions, ulcers
Vasculitis- Tx
-Tx underlying issue
-Vit. E
-Tetracycline and niacinamide
Histopath of endocrine dermatoses
-Impossible to definitively differentiate one from another based on histo changes
-Typically displays numerous telogen hair follicles, follicular dilatation, follicular hyperkeratosis, and a thin epidermis
Alopecia X- General
-Adrenal sex hormone imbalance
Alopecia X- Etiology
-Thought to represent a 21-hydroxylase deficiency (adrenal enzyme)
Alopecia X- Signalment
-Pomeranians and plush coated breeds
-1-5 y/o
Alopecia X- Cx
-Progressive loss of primary hair over neck, tail, trunk
-Head/limb hair spared
Alopecia X- Dx
ACTH sex hormone stimulation testing
-Offered by U of Tenn
Alopecia X- Tx
-purely cosmetic
-Melatonin may work
-Mitotane is effective but has lots of SE's (kill adr gland)
-Tilostane (special FDA approval) safe and effective
Hyperestrogenism of intact females- General
-Ovarian imbalance type I
-Rare in dogs
-Very Rare in cats
-Middle aged bull dogs
Hyperestrogenism of intact females- Cx
-Bilateral alopecia of the flanks and perineum
-Nipples/vulva enlarged
-Irregular estrous cycles
Hyperestrogenism of intact females- Dx
-Measuremt of serum estrogen levels, or response to OVH (may take 1-6 mos)
Estrogen reponsive dermatosis of neutered females- General
-Ovarian imbalance type II
-Rare in dogs
-Dachshunds and Boxers more
Estrogen reponsive dermatosis of neutered females- Cx
-Infantile nipples/vulva
-Diffuse alopecia of trunk begins at flanks/perineum
Estrogen reponsive dermatosis of neutered females- Dx
-Based on Cx and response to therapy
-Diethylstilbesterol or estradiol usually effective
Hyperestrogenism in males- General
-Dogs w/ testicular tumors
-Cryptorchid testes are 10x more likely to dvlp tumors
Hyperestrogenism in males- Cx
-Bilateral alopecia
-Non-neoplastic testicle atrophied
Hyperestrogenism in males- Dx
-Blood estrogen levels
-U/S of testicles
-Response to neuter w/in 3 mos
Pinnal alopecia of Dachshunds
-Usually males
-Slow onset ~6 mos old
-Bilat pinnal alopecia
Alopecia of American water spaniels ad Portugues water dogs
-Onset ~6 mos old
-Ventral neck, caudomedial thighs, and tail alopecia
Greyhound Bald thigh syndrome
-Caudal/lateral thigh alopecia
-may be related to stress of racing
Regional pattern baldness
-Usually females
-Hypotrichosis involving postauricular, ventral neck, ventrum, and caudal thigh regions
Follicular Dysplasia- General
-Weak hairs are susceptible to breakage d/t rubbing
-Regrowth is thinner/weaker
Follicular Dysplasia- Cx
-Cx varies w/ breed
-Husky and malamute
-Onset at 3 mos - 4 yrs
-Progressive loss of primary guard hair on the trunk
-Doberman, min-pin
-Onset 1-4 yrs in black/red dogs
-Progresses from flanks to dorsal trunk
-Irish / portuguese water dogs
-Hair loss over cd dorsum to most of trunk
-Regrowing hair is of a coarse texture
Seasonal Flank Alopecia
-Localized follicular dysplasia
Regrowth in 3-6 mos
-Alopecic patches have distinct borders and dvlp hyperpigmxn
-Melatonin may be effective
-Color dilution alopecia
-Blue dilutions/ fawn dilutions of darker colors
-Dobies, Dachshunds, Gread danes, Whippets, chows
-Lg macromelanosomes w/ irregular distribution in hair shafts
-Dorsal distribution
-Bacterial folliculitis com'n
-Tx usually unrewarding
Solar Dermatitis
-UVB--> sunburn cells (vacuolated keratinocytes)
-Incr. histamine, PG's, Inflamm CK's, O2 radicals
Feline Solar Dermatitis- General
-Affects pinnae, eyelids, and/or nose of cats that are white in those areas
-May progress to SCC
Follicular Dysplasia- Tx
-Sun avoidance
-Synthetic retinoid tx (Acetretin) $$$
-Ear tip amputation
Burns- Partial thickness
Burns involve the epidermis and superfical dermis
-Epithelializatino w/o scarring is possible
Burns- Full thickness
Burns involve the deep dermis including all cutaneous structures
-Second intention healing and scarring result
Burns d/t heating pads/cage driers cx
-results in hard and dry skin
Burns d/t chemicals, electric, microwaves cx
-These burns appear erosive and/or necrotic
Burns- Tx
-Fluid therapy
-Pain mgmt
-Topical abx against Pseudomonas spp- Silver sulfadiazine
-Surgical debridement/excision
Chronic radiant heat dermatitis
Alopecia, erythema, ulceration d/t chronic use of wood stoves, infrared lamps
Ichthyosis- General
-Rare congenital dz w/ excessive scale and hyperkeratosis
-WHWT predisposed
Ichthyosis- Cx
-Hyperpigmented and scaly at birth
-Peeling by 2 wks old
-Hyperkeratosis of footpads and planum nasale
Ichthyosis- Tx
Management best care
-Frequent bathing
-Emollient shampoos/rinses
-Acretin may be helpful
-Chronic dz
Ehler-Danlos Syndrome- General
-AKA- Cutaneous asthenia, dermatosparaxis
-Rare dz causing hyperextensibility and fragility of skin
-Abnormal collagen synthesis or fiber formation
-Various modes of inheritance
Ehler-Danlos Syndrome- Cx
-Skin hyperextensibility
-Skin easily torn
-Decreased elasticity
-Scars from prev injuries
-Jt laxity
-Lens luxation
Ehler-Danlos Syndrome- Tx
-Poor prognosis requires dedicated owner
-Maintain injury-proof environment
-Repair lacerations as they occur
-Declaw cats
Idiopathic Primary Seborrhea- General
Com'n hereditary keratinization abnormality
-Epidermal cell renewal = 8d in affected dogs, 21d in normal dogs
Idiopathic Primary Seborrhea- Signalment
WHWT (autosomal recessive)
-Cocker spaniel, bassets, English springer spaniel
Idiopathic Primary Seborrhea- Cx
-Severe seborrhea by 12-18mos
-Ceruminous, hyperplastic otitis externa
-Dull, scaly coat
-Greasy, stinky
-Alopecia, scale, erythema around eyes
Idiopathic Primary Seborrhea- Dx
-Rule out causes of 2ndry seborrhea
-Histopath--> Follicular hyperkeratosis, perivascular dermatitis
Idiopathic Primary Seborrhea- Tx
Long-term mgmt required
-Antiseborrheic shampoo
-Control secondary pyoderma and Malassezia dermatitis
-Synthetic retinoids may help (acitretin)
-Vit. A therapy
-Pred may help
Schnauzer comedo syndrome
-Hereditary condtn of min schnauzer
-Multifocal comedones and crusted papules
Idiopathic facial dermatitis of Persians/Himalayans
-AKA- Dirty face syndrome
-Periocular, muzzle, perioral, ear and chin rgns
-Brown/black exudate on skin/hair
-Tx often unrewarding
Sebaceous adenitis- General
-Unknown etiology
-Lesions more com'n in long-haired dogs
Sebaceous adenitis- Lesions in long-haired dogs
-Prominent follicular hyperkeratosis
-Dull, brittle hair
-Patches of alopecia and abnormally coarse, straight hair
-Ceruminous otitis externa com'n
Sebaceous adenitis- Tx
-Long-term bathing programs with antiseborrheic shampoo
-Soak w/ prop.glycol or oil mixtures prior to shampooing
-Acecretin and Atopica have been used
Idiopathic Nasodigital hyperkeratosis
-Hyperplastic keratin on the nasal planum and footpads
-May also be seen w/ other dermatoses
Plasma cell pododermatitis
Rare, idiopathic dz of feline footpads
-Swollen, soft, finely scaled pads
-Histo--> plasmacytic dermatitis
-Polyclonal gammopathy may be present
Canine familial dermatomyositis
Hereditary and idiopathic inflamm dz
-Collies mostly
-Onset 6 wks-6 mos
-Alopecia, erythema, scales, crusts, ulcerations
-Muzzle, periocular, ear tip, tail tip, carpus/tarsus
-Myositis seen later
-atrophy of musc of mastication
Canine familial dermatomyositis- Tx
-Avoid physical trauma
-Vit. E
Idiopathic sterile granuloma and pyogranuloma syndrome
Uncom'n, affects all breeds
-Multiple non-pruritic papules, nodules, plaques on nose, muzzle, pinnae, paws
-Alopecia and infxns secondarily
Idiopathic sterile granuloma and pyogranuloma syndrome- Tx
-Sx excision of solitary nodules
Sterile juvenile granulomatous dermatitis and lymphadenitis- General
AKA- Puppy strangles, juvenile cellulitis/pyoderma
-Unknown etiology
-3wk - 4mos
-Pred for tx
Tympanic mb parts
Pars tensa (ventral)
Pars flaccida (dorsal)
Stria mallearis (manubrium of the malleus)
Further diagnostic procedures of the ear
-Ear mite prep
-Bacterial C & S testing
-Tympanometry (waves shot at and measured as they bounce back)
-Palpation of the TM with a catheter (don’t do this one)
Com'n bacteria found in the ear
-S. intermedius
-Pseudomonas spp.
-Proteus spp.
-E. coli
-Klebsiella spp.
Com'n yeast found in the ear
-Malassezia pachydermatis
-Candida albicans
Principles of therapy- Ear dz's
-Control predisposing, secondary, perpetuating factors
-Ear cleaning
-Topical Tx
-Systemic Tx
Ear cleaning and drying agents- Saline
-Safe, used to get our ceruminolytics
Ear cleaning and drying agents- Antimicrobials
Ear cleaning and drying agents- Oil-based ceruminolytics
-Help soften and dislodge debris in ears
-Squalene, Propylene glycol, min oil, glycerin
Ear cleaning and drying agents- Water based ceruminolytics
-Dioctyl Sodium Sulfosuccinate (DSS)
-Calcium sulfosuccinate
-Carbamate peroxide
Ear cleaning and drying agents- Alcohol-based drying agents
-Boric acid
-Benzoic acid
-Salicylic acid
-Safe to use when the TM is torn, least likely to cause ototoxicity
-made up of:
isopropyl myristate, petrolatum
Made up of:
Salicylic acid, prop. glycol and lactic acid
Made up of:
Salicylic acid, benzoic acid, malic acid, oil of eucalyptus
Com'nly used drugs for compounding ear medications
-Silver sulfadiazine
-Ticarcillin (for Pseudomonas)
Systemic Tx for ear infxns
-Enrofloxacin, Marbofloxacin, Cephalexin
Tx for stenosis of ear canal d/t hyperplasia
-Course of high dose prednisone
-Infuse with cortisone
Puncture TM to Tx mid ear
-5 o'clock left ear
-7 o'clock right ear
Heals w/in 3-5 wks
TECA- Complications
-Horner's syndrome
-Facial n. paralysis
-Hearing loss
Mycosis Fungoides- General
-Uncom'n, affects both cats/dogs
-Generally of T-cell origin
Mycosis Fungoides- Cx
-pruritis, erythema
-Erythema, ulcers
-Oral mucosal dz
Mycosis Fungoides- Tx
-Grave prognosis (5-10mos)
-Systemic/topical chemotherapy
-Synthetic retinoids
Canine Oral papillomatosis
-Multiple smooth papules and plaques
-Progress to cauliflower-like masses
Cutaneous inverted papillomas
-Young dogs
-Ventral abdomen
-1-2cm plaque w/ central core
Papillomatosis- Histopath
-Papillated epidermal hyperplasia
-Ballooning degeneration
-Clumping of keratohyaline granules
-Basophilic intranuclear incl bodies
Papillomatosis- Tx
-Observation w/o tx
-Laser sx
-Surgical excision
Intracutaneous cornifying epithelioma
-Histopath- similar to papilloma w/ no ballooning degeneration
Basal cell carcinoma
-Com'n in cats, not dogs
-Low grade malignancy
-Generally solitary, melanotic, rounded nodules on the nasal planum/eyelids
Sebaceous gland tumors
Com'n in dogs, not cats
Older dogs