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143 Cards in this Set
- Front
- Back
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List the major causes of pruritis in the dog
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1. Ectoparasites
-Sarcoptes -Demodex (not as itchy, sometimes predominantly alopecia) 2. Infectious Organisms -bacterial infection -Malassezia dermatitis -dermatophytes (Asia) 3. Allergic Diseases -Atopy -Food Adverse reaction -FAD -Insect hypersensitivity -contact allergy/irritant -drug reactions 4. Autoimmune -Pemphigus foliaceus |
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Pruritis (dog)
-Sarcoptes scabei (Scabies/Sarcoptic mange) -Hx |
-highly contagious
-direct contact (foxes, grooming instruments) -very pruritic and non-responsive to a/b therapy and glucocorticoids |
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Pruritis (dog)
-Sarcoptes scabei (Scabies/Sarcoptic mange) -PE |
-primary, erythematous maculopapular rash
-may have yellow, dry easily crumbled adherent crusts or excessive scaling -INTENSE PRURITIS -chronic cases may show: hyperpigmentation and lichenification, secondary superficial pyoderma is common -patients may lose weight and become emaciated |
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Pruritis (dog)
-Sarcoptes scabei (Scabies/Sarcoptic mange) -Dx |
1. Skin scraping
-superficial skin scraping: pinnal margine, elbows, hocks and ventrum -select areas of papular eruption with yellow crusts that are not excoriated -negative skin scrapings do not rule out disease 2. Pinnal-pedal reflex (non-specific) 3. Therapeutic trial |
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Pruritis (dog)
-Sarcoptes scabei (Scabies/Sarcoptic mange) -Tx |
-in contact dogs in multiple dog households
-topical acaricides (e.g. permethrin) -systemic acaricides**(e.g ivermectin, moxidectin) |
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Pruritis (dog)
Malassezia dermatitis -aetiology |
-lipophilic, nonmycelial saprophytic yeast, thick walled oval/ peanut shape
-normal resident of skin -predisposing factors: increased humidity, allergic disease, keratinisation defects, bacterial skin disease and possibly endocrine disease (hypothyroidism) |
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Pruritis (dog)
Malassezia dermatitis -Hx/signalment |
-WHWT, silky and australian terrier, chihuahua, poodles, german shepherds, cocker spaniels
-summer/highly humid months -history of allergy, bacterial pyoderma, keratinisation disorder, endocrinopathy |
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Pruritis (dog)
Malassezia dermatitis -CS |
-Pruritis
-focal, mutifocal or generalised -diffuse erythema, greasy surface exudate, scale (yellow +/- slate grey), marked odour, hyperpigmentation, lichenification and alopecia -ceruminous otitis externa -paronychia: reddish brown staining if the proximal claw or a waxy exudate in the claw fold, may lead to persistent pedal pruritis in a topic dogs |
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Pruritis (dog)
Malassezia dermatitis -Dx |
1. Cytology methods:
-direct impression smears (greasy, waxy, flat surface) -cotton swabs -skin scrapings and tape impressions (dry scale) 2. Cytological findings |
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Pruritis (dog)
Malassezia dermatitis -Tx |
Topical:
1. Shampoo 2. Rinses 3. Ointments, creams lotions 4. Systemic Treatment ** (ketoconazole) |
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Pruritis (dogs):
Initial Database |
Step 1:
-superficial and deep skin scraping -acaricidal trial (NB: Demodex easy to find: can rule out) Step 2: -cytology (Dermatophytes?) Step 3: -Wood's Lamp and fungal culture |
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Pruritis (dogs):
Flea bite hypersensitivity dermatitis -Hx |
-pruritic papular dermatitis in dogs that become sensitised to allergens produced by fleas
-no breed/ sex predeliction -any age, rare in <6 mo, common age=3-5 years. |
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Pruritis (dogs):
Flea bite hypersensitivity dermatitis -PE |
-papule (flea feeding site) +/- small crust
-dorsal lumbosacral area, caudomedial thighs, ventral abdomen and flanks -chronic pruritis: alopecia, lichenification, crusting, hyperpigmentation. Pyotraumatic dermatitis, secondary bacterial pyoderma and secondary dry or greasy scaling and odour -predisposed to atopic dermatitis |
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Pruritis (dogs):
Flea bite hypersensitivity dermatitis -Dx |
1. PE
-fleas +/- faeces (absence does not rule out disease) 2. Intradermal skin testing |
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Pruritis (dogs):
Atopy -Definition |
inherited predisposition to produce reaginic antibody to environmental allergens that in non atopic dogs do not cause disease
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Pruritis (dogs):
Atopy -Hx |
1. Breed predilections: GS, rottos, BT, WHWT, Boxers, JRT, SBT
2. more common in females 3.4months-7 years; 70% of dogs first manifesting signs by one year and before 3 years of age 4. initially have seasonal signs but eventually develop non seasonal signs |
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Pruritis (dogs):
Atopy -CS |
-pruritis involving face, feet: interdigital spaces, dorsal and plantar surface, distal extremities: carpal and tarsal areas, ant. elbows and ventrum
-alopecia, salivary staining, hyperpigmentation and lichenification NO PAPULAR REACTION +/-atopic otitis externa-pinna and vertical ear canal (waxy, erythematous, oedematous, pruritic) +/-secondary bacterial pyoderma, pyotraumatic dermatitis or acral pruritic nodules (lick dermatitis) +/- recurrent conjunctivitis +/- hyperhidrosis |
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Pruritis
-Atopy -Dx |
1. Hx
2. PE 3. RULE OUT other diagnoses (do not miss other disease) 4. Intradermal skin testing** 5. ELISA/RAST |
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Pruritis
-Atopy -Tx |
-Allergen Immunotherapy
-Allergen avoidance -glucocorticoids (i.e pred) -antihistamines -essential fatty acids -topical therapy -other immunomodulatory drugs |
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Pruritis
-Adverse food reaction/food allergy -Hx |
-no age/sex predilection
-no breed predilection -onset of clinical signs do not correlate with a change of diet (some patients on the same diet for years) -NON SEASONAL GENERALISED PRURITIS |
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Pruritis
-Adverse food reaction/food allergy -CS |
-pruritis +/- lesions (oedema, erythema, papules, and pustules)
-any body region (face, ears, perianal area may be more common) +/-recurrent pruritic unilateral pr bilateral otitis externa +/- recurrent secondary superficial pyoderma +/- concurrent gastrointestinal disturbances (intermittent vomiting, diarrhoea, colitis or borborygmi) |
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Pruritis
-Adverse food reaction/food allergy -Dx |
ELIMINATION DIET
-recurrence of CS when oral prevocation with a previously fed foodstuff -minimum of 6 weeks -hypoallergenic diets individualised for each patient -feed a novel source of protein and carbohydrates -diet free of additives -exclude all treats!! -test meal of dog's previous diet including treats for 10-14days, if allergy, should relapse w/in 24hours and 2 weeks of challenge. -sequential rechallenge involves feeding each of the major food items by adding one pur food ingredient to restrictive diet. |
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Pruritis(dog)
-Insect-bite hypersensitivity -Hx |
-no breed, sex, age predilection
-may be seasonal w. CS worse in warm weather |
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Pruritis(dog)
-Insect-bite hypersensitivity -CS |
-pruritis +/- erythematous maculopapular dermatitis
(chronic pruritis>>secondary alopecia, crusting, lichenification, secodary bacterial pyoderma=papules, pustules, crusted lichenified plaques) -glabrous skin or short-haired areas most commonly affected: abdomen, groin, ventral thorax, face, legs and pinnae |
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Pruritis(dog)
-Insect-bite hypersensitivity -Dx |
-Signalment (Hx, PE)
-Cytology: moderate to marked eosinophillic infiltrate (w/ pyoderma: bacteria + neutrophils) -Intradermal skin testing -Histopath (hyperplastic, superficial perivascular dermatitis w/ mononuclear cells, mast cells and eosinophils) -insect bite trial |
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Pruritis(dog)
-Insect-bite hypersensitivity -clinical management |
1. Avoidance if possible
2. insect repellent/environmental treatment inside and outside 3. fly screens 4. Add Capstar in case of flea allergy dermatitis |
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Pruritis (cat)
-Hx |
-excessive licking
-alopecia and skin plaques (self induced) -3 cutaneous reaction patterns: miliary dermatitis self induced symmetrical alopecia eosinophillic granuloma complex |
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Pruritis(dog)
-Insect-bite hypersensitivity -Hx |
-no breed, sex, age predilection
-may be seasonal w. CS worse in warm weather |
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Pruritis(dog)
-Insect-bite hypersensitivity -CS |
-pruritis +/- erythematous maculopapular dermatitis
(chronic pruritis>>secondary alopecia, crusting, lichenification, secodary bacterial pyoderma=papules, pustules, crusted lichenified plaques) -glabrous skin or short-haired areas most commonly affected: abdomen, groin, ventral thorax, face, legs and pinnae |
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Pruritis(dog)
-Insect-bite hypersensitivity -Dx |
-Signalment (Hx, PE)
-Cytology: moderate to marked eosinophillic infiltrate (w/ pyoderma: bacteria + neutrophils) -Intradermal skin testing -Histopath (hyperplastic, superficial perivascular dermatitis w/ mononuclear cells, mast cells and eosinophils) -insect bite trial |
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Pruritis(dog)
-Insect-bite hypersensitivity -clinical management |
1. Avoidance if possible
2. insect repellent/environmental treatment inside and outside 3. fly screens 4. Add Capstar in case of flea allergy dermatitis |
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Pruritis (cat)
-Hx |
-excessive licking
-alopecia and skin plaques (self induced) -3 cutaneous reaction patterns: miliary dermatitis self induced symmetrical alopecia eosinophillic granuloma complex |
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Miliary Dermatitis (cat)
-character -Causes |
-small, erythematous crusted papules (usually non-follicular)
Causes: -Ectoparasites: Notoedres cati, Cheyletiella spp, Otodectes cynotis, Demodex spp -Allergies: FAD, Mosquito, food, atopy, (allergy contact dermatitis) -Infections: superficial pyoderma, Dermatophytes*, Malassezia dermatitis -Neoplasia (old cats): mast cell tumour, epitheliotropic lumphoma, Urticaria pigmentosa (all cause papular eruption) -Immune mediated: pemphigus foliaceus, pemphigus erythematosus, cutaneous drug eruptions |
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Miliary Dermatitis (cat)
-Dx |
-General Clinical exam:
-atopy. physical signs of a behavioural disorder (e.g. excessive licking) |
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Pruritis (cat)
-Notoedric Mange -Clinical Features |
-Notoedres cati (Sarcoptidae)
-margins of pinnae; face, eyelids, neck and forelegs -erythematous papular rash>>thick, adherent, yellow-grey scale and crust formation -progressive: severe alopecia, lichenification, hyperpigmentation, excoriation -severe pruritis |
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Pruritis (cat)
-Notoedric Mange -Dx |
-superficial skin scraping (easy to find)
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Pruritis (cat)
-Notoedric Mange -Tx |
Ivermectin/Salamectin/Doramectin
-treat all in contact cats |
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Pruritis (cat)
-Otodectic Mange -Clinical features |
-Otodectes cynotis
-otitis externa, usually bilateral -severe pruritis -head, neck, dorsolumbar region and tip of the tail (migrating mites) -erythema, papules, crusting and excoriation |
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Pruritis (cat)
-Otodectic Mange -Dx |
-close examination of the ear canal w/ otoscope
-collect ear discharge and examine under low power microscopy (cotton bud>paraffin>slide) -negative skin scrapings do not rule out disease |
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Pruritis (cat)
-Otodectic Mange -Tx |
-clean ears w/ ceruminolytic agent and apply a mticide (e.g. pyrethrin or thiabendazole) to both ears for 3 weeks.
-ivermectin 0.2-0.4mg/kg PO q 7 days for 3 Tx or SC q 14d for 2 Tx -all in contact animals (inc. dogs) -Fipronil: 2-4 drops spot on in both ears repeated in 14 d -Salamectin** 6mg/kg -consider in-contact asymptomatic carriers |
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Pruritis (cat)
-Cheyletiellosis -Clinical features |
-C. blakei, highly contagious
-trunk (dorsal) -mild scaling and crusting, localised or diffuse alopecia and poor quality hair coat -widespread miliary dermatitis/self induced dorsal hypotrichosis -pruritis may be mild to severe |
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Pruritis (cat)
-Cheyletiellosis -Dx |
-direct examination w/ magnifying glass
-superficial skin scrapings -acetate tape impressions -hair/scale collected w. flea comb** -faecal flotation -THERAPEUTIC TRIAL (salamectin) |
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Pruritis (cat)
-Cheyletiellosis -Tx |
-all in contact animals
-Fipronil spray -Ivermectin -Salamectin -zoonotic lesions are self-limiting after eradication of the mites on the animals |
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Pruritis (cat)
-Demodicosis -Feline follicular demodicosis -organism/general pts. |
-Demodex cati
-follicular mite -localised and generalised forms -acquired adult demodecosis associated w/ underlying systemic diseases (SLE, DM, HyperA, toxoplasmosis, FeLV, FIV, SCC) or Hx of immunosuppressive drug administration -not contagious between cats |
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Pruritis (cat)
-Demodicosis -Feline follicular demodicosis -Clinical features |
-Localised: single to multiple areas of patchy alopecia, variable erythema dn scaling of the eyelid, periocular region, head and neck +/- crusting
-Generalised: multifocal or generalised alopecia, erythema, crusting and hyperpigmentation of head, limbs and trunk -ceruminous otitis externa -variable pruritis |
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Pruritis (cat)
-Demodicosis -Feline follicular demodicosis -Dx |
Skin scrapings
Histopathology (mild superficial and perifollicular to mural inflammation with mild acanthosis and hyperkeratosis. -Salamectin ineffective!-Biopsy for definitive Dx. |
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Pruritis (cat)
-Demodicosis -Feline superficial demodecosis -organism and general pts. |
-D gatoi
-non-follicular mite, blunted abdome, predominantly inhabits stratum corneum -contagious, transmissible, pruritic skin disease, asymptomatic carrier status -variable pruritis -no evidence of underlying disease -Siamese and Burmese may be predisposed |
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Pruritis (cat)
-Demodicosis -Feline superficial demodecosis -CS |
-pruritis (>D.Cati)
-mild pruritis: symmetric alopecia +/- scale; ventral and lateral trunk and caudal legs -intense pruritis: similar lesions + erythema, scaling, crusting, excoriations |
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Pruritis (cat)
-Demodicosis -Feline superficial demodecosis -Dx |
-superficial skin scrapings (beware excessive grooming)-if do not find mites: skin biopsy or miticidal trial
-tape stripping -faecal flotation -histopath (minimal inflammation, irregular acanthosis and hyperkeratosis w/ mites in the stratum corneum. No mites in hair follicles) |
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Pruritis (cat)
-Demodicosis -Feline superficial demodecosis -Tx |
-2%-5% lime sulphur dips
-Amitraz 0.0125% or 0.025% weekly -Ivermectin -milbemycin -salamectin INEFFECTIVE -treat all cats in household |
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Pruritis (cat)
-Flea bite hypersensitivity dermatitis -Hx |
-no age, breed or sex predilection (however, often young and seasonal-depends on geographic region)
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Pruritis (cat)
-Flea bite hypersensitivity dermatitis -Clinical features |
-moderate to severe pruritis
-papulaocrustus eruptions: +/-alopecia, excoriations, crusting and scaling +/- pigment changes, multifocal small melanotic macules (previous inflammatory sites) -dorsal lumbosacral region, caudomedial thighs, ventral abdomen, flanks and neck (NB cats infected w/ mites most likely to have secondary infection) +/- self induced symmetric alopecia and eosinophillic granuloma complex lesions -moderate to marked peripheral lymphadenopathy |
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Pruritis (cat)
-Flea bite hypersensitivity dermatitis -Dx |
1. Physical findings:
-fleas, flea faeces, eggs (may be impossible to find-grooming) -Dipylidium caninum infection 2. Intradermal allergy testing 4. Therapeutic trial** -1 mo w/ Capstar -oral nitenpyram OR topical fipronil/imadocloprid spot on |
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Pruritis (cat)
-adverse food reaction -general pts |
-non-seasonal priritic dermatosis
-most common food allergens: fish, beef, dairy |
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Pruritis (cat)
-adverse food reaction -Hx |
-more common in younger animals
-no breed/age/sex predilection (may be more common in Siamese/X) -good response to corticosteroid therapy |
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Pruritis (cat)
-adverse food reaction -Dx |
1. elimination diet trial
-confine cat inside -feed novel diet (kangaroo, horse, donkey, goat, camel, vinison, rabbit, pork) 2. Length of dietary trial: -minimum of 6 weeks -reintrodiction produces signs w/in 4-72 h -sequential food challenge (most cats only allergic to a single protein) |
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Pruritis (cat)
-adverse food reaction -Clinical management |
-feed limited protein source
-balanced home prepared diet -glucocorticoids, antihistamines, fatty acids if avoidance impossible |
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Pruritis (cat)
-Atopy -Hx |
-no breed/sex predilection (maybe Abyssinians)
-6 months to 3 years -seasonal or perennial |
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Pruritis (cat)
-Atopy -CS |
-pruritis: generalised or localised
-abdomen, groin, lateral thorax, caudal thighs, head nexk and forelegs -crusted papular eruptions (miliary dermatitis), self induced symmetric alopecia, eosinophillic granuloma complex; pruritis, erythema, crusting on face and neck. -recurrent, pruritic, ceruminous otitis externa -resp signs variable-sneezing, rhinitis, chronic cough (allergic bronchitis), dyspnoea (asthmatic wheeze) +/- bilateral erythematous blepharoconjunctivits +/- concurrent AFR or FAD (or both) |
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Pruritis (cat)
-Atopy -Dx |
-Hx. PE
-rule out adverse food reaction/flea allergy dermatitis -intradermal skin testing -withdrawl of corticosteroids (8-12 weeks) |
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Pruritis (cat)
-Atopy -Clinical Management |
-allergen specific immunotherapy
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Tx of cats w/ miliary dermatitis due to allergy
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-glucocorticoids (oral pred)
-antihistamines (cyproheptadine) -Fatty acids (evening primrose oil, fish oil) |
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Approach to cat w/ miliary dermatitis
-initial database |
1. screen for flea allergy (coat comb)
2. Screen for other ectoparasites (sup. and deep skin scraping) 3. Screen for dermatophytosis -wood's lamp 4. Screen for ear mite -paraffin preparation 5. screen for bacterial infection -ear and skin cytology |
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Approach to cat w/ miliary dermatitis
-further screeing |
6. Rule out Dermatophytosis
-fungal culture 7. Rule out mite infestation -acaricidal trial 8. rule out FAD -flea Tx trial 9. Screen for food allergy -elimination diet trial 10. screen for atopic dermatitis -intradermal allergy testing 11. screen for immune mediated, neoplastic or autoimmune disease -skin biopsy for histopath |
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Pruritis (cat)
-Self induced symmetrical alopecia -general |
-excessive licking
-hormonal alopecia extremely rare -bilaterally symmetrical |
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Pruritis (cat)
-Self induced symmetrical alopecia -DDx |
-Ectoparasitic: Demodicosis, Cheyletiellosis, Otodectic mange
-Infectious: Dermatophytosis, bacterial folliculitis -Allergic: FAD, atopy, food allergy -Endocrine: hyperA, hyperthyroid, DM, telogen effluvium -Behavioural-psychogenic -Systemic disease: feline paraneoplastic alopecia |
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Pruritis (cat)
-Self induced symmetrical alopecia -Hx |
-grooming behaviour?
-increased hair in environment? -hairballs? hair in faeces? -anxiety/alterations in environment -weight loss, pu/pd, pp, hyperactivity, vomiting, diarrhoea (hyperA, hyperthyroid), weight loss or GI signs (pancreatic neoplasia) |
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Pruritis (cat)
-Self induced symmetrical alopecia -PE |
-examine hair coat for nature and distribution of hair loss (hairs broken or easily epilated)
-ventral abdomen, medial fore and medial and caudal hindlimbs, caudal abdomen and inguinal region -coat may be completely lost/sparse + thin -short, stubby hairs -skin normal |
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Pruritis (cat)
-Self induced symmetrical alopecia -Dx |
1. Trichogram
-self induced vs. spontaneous alopecia 2. Organic vs. psychogenic --consider any underlying organic cause for pruritis |
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Pruritis (cat)
-Self induced symmetrical alopecia (psychogenic) -Tx |
-behavioural therapy
-anti anxiety drugs |
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-Feline Eosinophilic
granuloma complex -definition and underlying causes |
Definition: heterogenous group of cutaneous, mucocutaneous and oral lesions of cats subdivided into eosinophillic ulcer, eosinophillic plaque and eosinophillic (collagenolytic, linear) granuloma
Causes: -Allergies: FAD. food allergy, atopy, insect hypersensitivity -Infectious: bacterial -Others: genetic, idiopathic |
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-Feline Eosinophilic
granuloma complex 1. Eosinophilic (collagenolytic, linear) granuloma -cutaneous -Oral` |
1. Cutaneous:
-caudal thigh, medial aspect of forelegs -well circumscribed, raised, firm, non pruritic, yellowish to pink plaque -non-pruritic -+/- single or grouped, linear, papular, nodular or plaque lesions on face, bridge of nose, forelimbs, neck and thorax +/- pinkish yellow swellling of lower lip, rostral aspect of chin +/- footpad involvement 2. Oral: -firm, erythemic, raised nodules w. pale gritty white foci: tongue, frenulum or hard and soft palate -halitosis, anorexia, dysphagia, hypersalivation +/- peripheral lymphadenopathy |
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Feline Eosinophilic
granuloma complex 2. Eosinophilic ulcer (indolent ulcer/rodent ulcer) |
-well circumscribed, unilateral or bilateral ulcer
-philturm of upper lip -non pruritic, non painful |
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Feline Eosinophilic
granuloma complex 3. Eosinophilic plaque |
-intensely pruritic, well circumscribed, raised, moist, ulcerated, erythematous papules and plaques
-ventral abdomen, medial thighs, face and neck -peripheral lymphadenopathy |
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Feline Eosinophilic
granuloma complex -Dx |
1. Flea comb and evaluate for FAD
-flea control trial 2. skin scraping and cytology -impression smears -scrape>slide -FNA -a/b therapy 3. evaluate for underlyig food allergy -elimination diet 4. skin biopsy -rule out neoplasia 5. evaluate for underlying atopy -intradermal skin testing |
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Feline Eosinophilic
granuloma complex -Tx |
a. ID and manage identifiable underlying causes-flea allergy, food allergy, atopy, insect hypersensitivity
b. oral a/b -trimethoprim-sulfa; cephalexin, amoxy-clav c. glucocorticoids -oral prednisolone d. immunomodulating drugs -clorambucil, interferon, cyclosporin e. prostagestens |
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Pustule formation and Pyoderma
-pathogenesis |
-Staph. intermedius
-pyoderma is secondary -common predisposing diseases: allergic dermatitis, endocrinopathies, ectoparasitism |
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Pustule formation and Pyoderma
-Superficial pyoderma Clinical features: 1. Impetigo 2. Bullous impetigo |
1. superficial, non-follicular pustules due to S. intermedius
-young dogs -not contagious -small, superficial pustules that do not involve hair follicles -crusted papules -glabrous skin of ventral part of abdomen and axillae -pruritis uncommon and mild 2. secondary to immunosuppression or systemic disease; other bacteria (e.g Pseudomonas/ E. coli) may be present -large, flaccid, yellow-green non follicular pustules -pruritis uncommon |
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Pustule formation and Pyoderma
-Superficial pyoderma 1.Dx 2. DDx |
1. Hx & PE]
2. Superficial bacterial folliculitis, pemphigus foliaceus |
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Pustule formation and Pyoderma
-Superficial pyoderma -Tx |
a. topical antimicrobial therapy
(chlorhexidine/2% mupirocin cream) b. systemic a/b c. eliminate underlying factors |
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Pustule formation and Pyoderma
-Mucocutaneous pyoderma -Clinical features |
-GSD + X may be predisposed
-symmetrical swelling and erythema of lips and perioral skin, esp. at commissures -crusts entrap hairs. Fissuring, erosion and ulceration (severe) -chronic: depigmentation of lips -planum nasale, nares, philtrum, vulva, prepuce, anus -Dx on clinical exam |
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Pustule formation and Pyoderma
-Superficial pyoderma-bacterial folliculitis -Clinical features |
-common in dog, rare in cat
-pustule w/ hair shaft protruding from centre -follicular papules (earliest) +/- crust and scale>alopecia (moth eaten coat), hyperpigmentation, epidermal collarette formation (ring shaped 'collar' of scale) -axillae, abdomen, groin |
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Pustule formation and Pyoderma
-Superficial pyoderma-bacterial folliculitis -Dx |
-ID of superficial folliculitis
1. microscopic examination of smears from pustules: a) type of bacteria b) inflammatory cells c) acantholytic cells (indicates pemphigus-stratum spinosum cells w/o attachment) 2. culture and sensitivity 3. skin biopsy (chronic recurrent) 4. investigate underlying causes |
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Pyoderma and Pustular disease in dogs
-diagnostic plan |
1. pustules-examine stained smears ID bacteria
2. rule out exoparasitism (superficial and deep skin scrapings + coat brushings_ 3. wood's lamp + fungal culture 4. pruritis=a/b therapy 5. persisting pruritis=evaluate for allergy: elimination diet, IDST, flea control 6. pruritis resolved by a/b therapy: suspect hypothyroid/idiopathic pyoderma-evaluate CBC, biochem, urinalysis, LDDS, thyroid status 7. not resolved by a/b therapy-suspect immune mediated disease or another non-bacterial cause of pustular disease-collect skin biopsy for histopathology |
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Deep folliculitis and furunculosis
-general pts |
-deep follicular inflammation leads to follicular rupture releasing hair shaft keratin, bacteria and bacterial products into the dermis resulting in a furunculosis or infection of the dermis and subcutis
-S. intermedius +/- proteus, pseudomonas, E. coli (Hydrobath-bottle contamination (poor hygiene)) -localised or generalised -generalised demodicosis is the most common cause of deep pyoderma |
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Deep folliculitis and furunculosis
-Clinical features |
-papules, pustules that rupture and form dark brown or reddish crusts
-red or purple, raised, haemorrhagic bullae or nodules w/ draining, haemorrhagic purulent exudate -fistulous tracts with necrotic, friable tissue and discharging mucopurulent or haemorrhagic exudate -multifocal, tight adherent crusts -coat may be matted with dry exudate -groin, axillae, interdigital webs, pressure points, -lethargy, depression, and fever, pain and pruritis -regional and generalised lymphadenopathy |
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Deep folliculitis and furunculosis
-Dx |
1. Microbiology (tissue biopsy for bacterial culture and sensitivity for a/b selection)
2. Histopath 3. Investigate underlying causes |
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Actinic furunculosis
-definition |
-common, solar induced deep bacterial pyoderma
-solar induced preneoplastic and neoplastic changes (actinic keratosis, actinic comedones, SCC) |
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Actinic furunculosis
-Clinical features |
-lightly pigmented, sparsely haired dogs
-sunbathers -crusted erythematous nodules and haemorrhagic bullae -glabrous skin of ventral and lateral abdomen, inner thighs and dorsal muzzle -may be painful or pruritic |
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Pyotraumatic folliculitis
-definition |
-deep pyoderma not secondary to classical pyotraumatic dermatitis
-deep pyoderma initiates a similar clinical appearance through relentless self trauma superimposed over subjacent deep infection |
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Pyotraumatic folliculitis
-Clinical features |
-young dogs
-GR, BMD, St.Bernards, Lab, NFLD -painful, focal erythema and swelling with papules, pustules, plaque formation leading to ulceration, exudation secondary to self trauma -neck and head |
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Muzzle folliculitis and furunculosis (canine acne)
-definition |
-unknown cause
-secondary bacterial involvement -genetic predilection+self trauma - |
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Muzzle folliculitis and furunculosis (canine acne)
-Clinical features |
-short coated breeds
-papules centred on hair follicles>pustules>rupture>shed central hair>nodules -chin and lower lip |
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Feline acne
-definition |
-comedone formation and secondary inflammation on the chin and skin adjacent to the lips
-secondary bacterial involvement (w/ follicular rupture) |
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Feline acne:
-Clinical features |
-any age, no sex/breed predilection
-early: solitary comedones containing dark, inpissated material around the lateral commissures of the mouth, lower lip and chin -multiple small flakes of discoloured keratin debris -mildly erythematous crusted papules +/- regional lymphadenopathy |
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Feline acne:
-Dx |
1. Skin scrapings
2. impression smears 3. fungal culture 4. skin biopsy |
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Feline acne:
-Clinical Management |
1. Topical therapy
-clip area -hot pack w/ Epsom salt for 5-10 min 2. Systemic a/b 3. Cleaning agents 4. Topical ointments 5. fatty acid supplementation 6. prednisolone 7. systemic retinoids |
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Pedal folliculitis and furunculosis
-definition |
-interdigital pyoderma
-short, bristly hairs rubbing against the skin of apposing digits -trauma or self trauma, FB -idiopathic, recurrent bacterial infections |
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Pedal folliculitis and furunculosis
-History and clinical features: |
1. History:
-brachycephalic breeds w/ poor conformation and short bristly hair coats (boxers, eng. bulldogs, mastiffs, bull mastiffs) 2. Clinical features -nodules, ulcers, haemorrhagic bullae, fistulae -front feet -maceration, chronic moistness and surface secondary bacterial and Malassezia due to licking -feet may be swollen -regional lymphadenopathy -no sex/ age predilection |
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Pedal folliculitis and furunculosis
-Dx |
1. Multiple skin scrapings
2. exudative cytology study 3. evaluate for underlying aetiology 4. fungal culture 5. bacterial culture 6. histopathology 7. radiographs 8. evaluation of the immune system (hemogram, serum IgG, free T4, LDD) |
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Pedal folliculitis and furunculosis
-Tx |
-twice daily foot soaks-aqueous chlorhex + 0.5% chlorhex spray
-topical 2% mupirocin ointment on indiv. lesions -a/b (8-12 weeks) -palpate lesions (pain=still infected) -treatment should be continued as long as lesions are present -severe: fusion podoplasty |
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Acral lick furunculosis
-definition |
-excessive, compulsive, licking
-multifactorial aetiology -secondary deep bacterial folliculitis and furunculosis=self trauma>follucular rupture>hair displacement in deep dermis -Staph |
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Acral lick furunculosis
-Clinical features |
-large, active, attention demanding breeds (DP, GD, GSD, Lab, I Setter)
-well circumscribed, firm, alopecic lesions, solitary, oval 2-6cm, crateriform, irregular ulcer surrounded by hyperpigmented halo -dorsal carpal and metacarpal areas |
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Acral lick furunculosis
-Dx |
1. Cytology
2. Microbiology 3. skin biopsy 4. radiography |
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Acral lick furunculosis
-Tx |
1. Determine cause of infection
(often transient insult to skin) 2. Prevent licking -bandaging -E. collar 3. A/b -Cephalexin 4. topical antipruritic and antiinflammatory therapy -DMSO/fluocinolone acetonide -capsaican 0.25% -2% mupirocin |
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Alopecia
-Canine Demodicosis -Clinical features |
-Demodex canis
-localised/generalised Localised: one to several small, circumscribed lesions -focal erythema, scaling and hyperpigmentation+/- papules or pustules w/ secondary pyoderma -young dogs, resolve w/o Tx Generalised: 5+ lesions, involving entire body region, complete involvement of 2 or more feet -diffuse, erythematous scaling w/ follicular pluggind and follicular casts and large areas of prominant hyperpigmentation w/ comedones -S. intermedius Juvenile: <12 mo (sm, med) <18 mo (giant) NB: must not be used for breeding Adult: 4 years +, no known Hx of disease; cutaneous marker of systemic disease (acquired immunosuppression-hyperA, hypothyroid, malignant neoplasia, iatrogenic hypercortisolism) |
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Alopecia
-Canine Demodicosis -Dx |
-deep skin scrapings
-hair plucks -histopathology |
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Alopecia
-Canine Demodicosis -Clinical management |
Localised: does not require Tx
Generalised: amitraz dips/ivermectin PO, milbemycin oxime -treatment continued until two consecutive multiple deep scrapings are negative and then for an add. 30-60d (4-6 sites min) |
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Alopecia
-Dermatophytosis -definition |
-Microsporum canis (or M. gypseum, Trichophyton mentagrophytes)
(NB: last 2 do not react under Wood's lamp) -Main DDx: Demodex |
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Alopecia
-Dermatophytosis -CS |
-circular patch of alopecia w/ scale, crust, central hyperpigmentation and follicular papules
-face, pinnae, paws and tail |
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Alopecia
-Dermatophytosis -Dx |
Direct microscopic exam
wood's lamp fungal culture |
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Alopecia (non-inflammatory)
-Alopecia X -CS |
-Chow Chow, Keeshond, Pom., Somoyed
-9 mo-2 years -male dogs more common -symmetric alopecia and hyperpigmentation |
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Alopecia (non-inflammatory)
-Alopecia X -Dx -Tx |
-exclude all other causes
-normal routine screening (CBC, biochem, urinalysis) Tx: CASTRATE melatonin, methyltestosterone, opDDD, trilostane, GH supp. |
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Diagnostic approach to localised and multifocal alopecia
|
1. Rule out demodicosis
-skin scraping -hair plucks 2. Rule out dermatophytosis -Wood's lamp -fungal culture 3. Rule out alopecia areata, steroid injection site, sebaceous adenitis, colour dilution alopecia, dermatomystitis -skin biopsy |
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Diagnostic approach to generalised alopecia
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1. Rule out obvious causes (testicular neoplasia, ovarian cycle abnormalities)
-PE 2. Rule out demodicosis -skin scrapings -hair plucks 3. Rule out dermatophytosis -Wood's lamp -Fungal culture 4. Rule out endocrine disease -Trichogram -Haematoogy -Biochem -Urinalysis 5. If initial results suggest hypothyroid: thyroid function tests (total T4) 6. If initial results suggest hyperA -adrenal fxn tests (LDDST) 7. Rule out and distinguish between hormone/adrenal sex hormone/follicular dysplasia/flank alopecia/CDA/anagen-telogen defluxion/paraneoplastic alopecia |
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Alopecia (cat)
Dermatophytosis (common) -Organism and transmission |
-M. canis (or M. gypseum, Trichophyton mentagrophytes)
-direct contact |
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Alopecia (cat)
Dermatophytosis (common) -PE |
+/- pruritis
Kittens: irregular, annular to circular patch of alopecia w/ scale, crust and erythema on ears, face, forelegs Adults: patchy alopecia, focal, multifocal or generalised +/- scale, long haired cats -chin folliculitis, onychomycosis, generalised seborrhea |
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Alopecia (cat)
Dermatophytosis (common) -Dx |
-direct microscopic examination
-Wood's lamp examination (screening for M. canis) -Fungal culture** |
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Alopecia (cat)
Feline paraneoplastic alopecia -Clinical features |
-usually pancreatic neoplasia
-older cats -alopecia: ventral abdomen, thorax, legs>>generalised +/- excessive grooming -smooth, shiny, glistening in areas of alopecia -pads are dry, scaly and shiny w/ multiple concentric, circular rings of scale -secondary Malassezia dermatitis is common (immunocomprimise) -lethargy, inappetance, weight loss |
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Alopecia (cat)
Feline paraneoplastic alopecia -Dx |
1. histopathology (skin biopsy has typical appearance)
2. Abdominal radiography and u/s evalation +/- exploratory laparotomy and biopsy |
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Alopecia (cat)
Feline paraneoplastic alopecia -Tx |
-none
-metastasis to liver and lungs has generally occured -most cats die or are euthanised within a month of diagnosis |
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Approach to spontaneous hair loss in the cat
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1. check for: drugs, illness that could have triggered anagen or telagen defluxion (rare)
-PU/PD; weight loss, vomiting, diarrhoea, pyrexia, preg/lactation, Sx 2. Skin scrape (Demodex) 3. Wood's lamp + fungal culture (dermatophytosis) 4. blood sample -CBC, biochem, total T4, FIV, FeLV, -urinalysis 5. skin biopsies Stage 2 1. HyperA suspectes: ACTH stim test, LDDST 2. Hyperthyroid: free T4, exogenous TSH |
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Diagnostic approach to scaling and crusting in dogs and cats
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1. Hx and PE
2. Diagnotic tests (initial): -skin scrapings, coat brushings, acaricidal trial -Wood's lamp examination and fungal culture -cytology-pyoderma/Malassezia dematitis, assess for response to a/b Persistant scaling + Pruritis: Assiss for hypersensitivity: -Flea bite allergy -Insect bite hypersensitivity -adverse Food reaction -Atopic dermatitis (FIFA) 3. Diagnostic tests (supp) -Flea and insect bite trial -elimination diet -intradermal test/ELISA Persistant scaling w/o pruritis -rule out Demodex -evaluate for endocrinopathy -evaluate for metabolic disease (hepatocutaneous, drug eruption) -evaluate for autoimmune disease (pemphigus, CLE/SLE) -evaluate for neoplasia (epitheliotrophic lymphome) -evaluate for environmental factors (low humidity) 4. Other supp tests: -CBC, biochem, urinalysis -FeLV, FIV -serum ANA -Total T4 -LDDST -skin biopsy for histopath IF all tests normal, consider primary cornification disorder: -Primary idiopathic seborrhea -VitA resposive dermatosis -sebaceous adenitis -canine ichtyosis |
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Primary seborrhea
Clinical features |
-inherited abnormalities of cornification in specific breeds (Am CSp, ESS, Bas. hound, sharpei, DP, IS, GSD, Mini Sch, Dachs.)
-hyperproliferatice epidermis, hair follicle and sebaceous glands -primary wpidermal cell defect -<12mo -focal to diffuse accumulation of white to grey non-adherent scale -Spaniels, BH, Sharpei: greasy, malodorous skin and hair coat -erythematous, multiple, discrete to coalescent circular plaques -thorax +/- pruritis |
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Primary seborrhea
-Dx |
-exclude all secondary causes of scaling and supportive findings on histopath. examination of a skin biopsy
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Primary seborrhea
-Histo |
-hyperkeratosis
-keratin amorphous and loosely layered |
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Canine ear margin dermatosis
-definition |
-abnormality of cornification
-lesions confined to margins of the pinnae -Dachsund (hereditary) |
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Canine ear margin dermatosis
-Clinical features |
-small, greasy to waxy, tenacious to exfoliative, yellow to brown plugs (follicular casts)
-pinnal margins and apex of ears +/- partial alopecia +/- fissuring and secondary bacterial infection (chronic, severe) |
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Canine ear margin dermatosis
-Dx |
-clinical
-rule out pinnal vasculitis (deeper) |
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Canine ear margin dermatosis
-Tx |
-incurable
-suphur-salicyclic, tar, benzoyl peroxide -topical/systemic glucocorticoid |
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Nasodigital hyperkeratosis
-Clinical features |
-C. Sp, Beagles, Basset H, Bengal cats
-late middle aged to older -nasal planum-hard, dry, rough and hyperplastic -prominent, adherent, dry keratinous material -footpads: proliferative debris (esp at pad margins) |
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Nasodigital hyperkeratosis
-Dx |
Other diseases:
Nasal only: pemphigus erythematosus, discoid lupus erythmatosus, nasal parakeratosis Feet only: pemphigus foliaceus, cut. lupus eryth., disc lupus eryth, k9 distemper, Zn resp. dermatosis, generic dog food dermatosis, superficial necrolytic dermatitis, ichthyosis, familial footpad hyperkeratosis |
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Nasodigital hyperkeratosis
-Dx workup |
-CBC, serum biochem
-skin biopsy for histopath -ANA testing |
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Define:
1) erosion 2) ulcer |
1) shallow disruption of the epithelium that are not deep enough to involve any significant portion of the dermis
2) deeper disruptions of the epithelial and dermal submucosal tissues and epithelial disruption usually 2o to process centered in the dermis or SC tissue NB: all diseases DIAGNOSTIC on skin biopsy |
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Discoid lupus erythmatosus
-CS |
-autoimmune skin disease
-Collies, GSD, shet. sheepdogs, Sib. Huskies -depigmentation, erythema and scaling on planum nasale-bilaterally symmetrical -early: slate blue or grey colour change w/ loss of normal 'cobblestone' architecture -late: erosion, ulceration and crusting |
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Discoid lupus erythmatosus
-Dx |
1. Histopathology**
2. Direct IF |
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Diagnostic Summary: ulcers/erosions:
|
Primary lesion (e.g. pustule)>cytology
V w/o>biopsy and tissue culture V blood work (sick)>check for anaemia/liver disease |
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Diagnostic plan for Nodules, discharging sinuses and non-healing wounds
|
1. FNA, impression smear of exudate, or scraping of margin of lesions (3-4 specimens)
2. Skin biopsy-aerobic, *anaerobic and deep fungel culture* -histopath + DDx list 3. WEAR GLOVES (zoonoses) |
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Otitis externa
-common primary causes |
Hypersensitivity:
ATOPY*** Food allergy Contact Drug eruption Parasites -Otodectes cynotis Keratinisation disorders -Primary -endocrinopathies Foreign Bodies -Grass seeds -hair -medications Obstructive -ear canal tumours -ceruminous gland hyperplasia |
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Otitis externa:
-perpetuating factors (prevent resolution) |
-progressive narrowing of ear canals
-ear canal fibrosis -ear canal calcification -cholesteatoma -OTITIS MEDIA |
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Otitis externa:
-Dx procedures |
1. Otoscopic exam:
-examine external ear canal for: erythema, patency, stenosis, exudate, proliferative changes, ulceration, FB, parasites, tumours -examine tympanum for colour, distension and integrity (dark grey, brown in OE; may be ruptured) 2. Cytology -increase in anucleate and nucleate squames and debris -proteinaceous debris and neutrophils +/- bacteria (e.g Staph) +/- Malassezia -examine for otodectic mange 3. Bacterial culture and sensitivity (4. Radiography) |
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Diagnostic summary: ear discharge and head shake
|
1. ID secondary disease-cytology (also determines therapy)
2. Determine primary disorder-unilateral=neoplasia, FB; Atopy=bilateral (but one ear may have secondary microbial overgrowth) 3. determine contributing/predisposing factors 4. consider any perpetuating factors |
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Otitis externa and media
-Treatment summary-if inflamed, stenotic, exudatice ear canal |
1. topical/systemic a/b based on cytology
2. oral pred 0.5mg/kg q 12h tapered weekly to every 24h and then every 48h 3. schedule a revisit for follow up in 1-2 weeks (recheck and repeat cytology) 4. prepare the client for longer term topical and systemic therapy (i.e. 6-8 weeks longer in very chronic cases) 5. Withdraw therapy when cytology -ve on 2 evaluations 1 week apart 6. introduce combination cleanser (drying agent) 1-2 X a week 7. Evaluate for underlying 1o disease |
