Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/57

Click to flip

57 Cards in this Set

  • Front
  • Back
Describe the pathogenesis of atopic dermatitis.
Atopic dermatitis is “strange disease” and is a familial predisposition to the development of IgE antibodies and clinical allergy to environmental antigens
Describe the lesions and distribution pattern of atopic dermatitis
Lesions:
-Erythema
-Alopecia
-Papules
-Excoriations
-Hypepigmentation
-Lichenification
Distribution:
-Muzzle
-Periocular
-Axillae
-Feet
-Flexor surfaces of elbows and tarsus
-Extensor surface of carpus
-Lesions may become generalized in chronic cases
What are the advantages and disadvantages of RAST?
Advantages
-Very specific

Disadvantages
-Poor reproducibility
-Poor specificity for IgE
-Many false positives
-Great seasonal variability
What are the advantages and disadvantages of IDST?
Advantages
-Gold standard for determining allergens
-Shows whether or not an allergen is capable of producing skin lesions in the tested patient
-Immediate results

Disadvantages
-Owners refuse clipping of fur
-If skin does not respond to the histamine, it won’t respond to injected allergens
-No access to the test
How do you interpret a negative IDST?
-Patient not allergic to reaction
-SQ injection given
-Insufficient antigen
-Concurrent drugs blocked the skin test (this is why they must be off drugs before testing)
-Prolonged allergy (exhaustion of IgE levels)
How do you interpret a positive IDST?
-Patient allergic to antige
-Patient allergic to the cross reacting antigen
-Irritants
-Bacterial or fungal contamination
-Antigen contains histamine
-Too large volume injected
What are the advantages and disadvantages of using corticosteroids for the treatment of atopic dermatitis?
Advantages
-Very effective at decreasing skin inflammation and itching

Disadvantages
-Many side effects (PUPD, panting, weight gain, increased risk of infection, ect.)
-Use only if other therapies are not feasible
What are the advantages and disadvantages of using cyclosporine for the treatment of atopic dermatitis?
Advantages
-Effective in severe allergy cases for decreasing skin inflammation and itching
-Suppresses T cells and decreases IgE production
-Decreases production of cytokine

Disadvantages
-Side effects (GI, renal, hepatic, bone marrow)
-Costly
What are the advantages and disadvantages of using hyposensitization (immunotherapy) for the treatment of atopic dermatitis?
Advantages
-Increases T suppressor cell activity, w/ gradual decrease in IgE
-Blocks antibodies
-Decreases number of mast cells and/or decreases histamine release from mast cells

Disadvantages
-May req. 9 months or longer to obtain maximal effectiveness
-25-50% chance of not working or needed additional treatment
Discuss client education of the treatment of atopic dermatitis.
-Must communicate that the animal is a walking dust mite and they must be bathed frequently
-Also, if animal is allergic to material in house or what owner wears, significant changes must be made
-Owner must be committed to working w/ the disease or the animal will suffer for their entire life
Describe the MOA of glucocorticoids in treatment of allergy.
-Glucocorticoids block Cox 1 and 2 as well as phospholipase A (which is needed to make Prostaglandins)
Describe the benefits of antihistamines in cats and dogs
-Antihistamines are a good preventative drug, just not great for treatment
-Block H1 and H2 receptors
-Stabilize mast cells
-Few side effects
Describe the physiological basis of alternate day steroid administration.
-Alternate day therapy is an attempt to control the animals atopy while giving them less drug. This will decrease the potential for side effects and resistance.
Are lamb and rice nonallergenic?
-NO- lamb and rice are not non-allergenic (many animals are, in fact, allergic to lamb)
Why are lamb and rice chosen for some hypoallergenic diet trials?
-Lamb and rice are chosen however for some hypoallergenic diets b/c lamb is a novel protein and if the animal has never tried lamb it might be worth a try. Rice is added in as the carbohydrate source
Devise a restrictive diet trial for a cat or dog for which you have been presented with a list of its past diet.
HOME COOKED DIETS
-Choose a protein source that the animal has never been exposed to (lamb, fish, venison, rabbit, tofu, pinto beans)
-Choose a carbohydrate source (brown rice, white rice, potatoe, green peas)
-Mix the two as a 1 part protein : 3-4 part carbo
STORE DIETS
-Again look for a protein source the animal hasn't tried (Hill D/D, Z/D or Purina HA)
What are the DDX of a cat w/ pruritis on its head and neck.
-Food allergy
-Ear mites
-Notoedres
-Flea allergy dermatitis
How can you differentiate allergic contact dermatitis from an irritant contact dermatitis?
Allergic Contact dermatitis:
-An inflammatory skin disease caused by a delayed (cell-mediated) response to an antigen or hapten. Requires repeated or continuous exposure to the substance
Irritant Contact Dermatitis:
-An inflammatory skin disease which occurs within minutes of contact w/ irritating substance
Outline measures that can be used to minimize an animals exposure to housedust mites.
-Remove carpets, blinds, plants, upholstered furniture, cluster
-Use plastic encasings for mattresses, boxsprings, pillow
-There are some products to kill HDM
Describe the clinical presentation of erythema multiforme.
-Erythematous macules and papules that spread
-Urticarial plaques that last for many days
-Vescilces/bullae
-Any combo of these
Describe the clinical presentation of Toxic Epidermal Necrolysis.
-Vesicles/bullae
-Necrosis
-Systemically ill
-Entire epidermis of the lesion can be necrotic and slough off
What are the usual causes of Toxic Epidermal Necrolysis.
-Drugs***
-Toxins
-Infections
-Neoplasms
What are the usual causes of Erythema Multiforme.
-Drug allergies ***
-Trimethoprim/sulfa
-Cephalexin
What are some etiologies for feline miliary dermatitis?
-Ectoparasites
-Dermatophytes
-Allergies
-Nutritional
-Bacterial
-Contact
-Autoimmune
-Idiopathic
What is a diagnostic plnn for feline miliary dermatitis?
-Examine for parasites
-Woods light
-DTM culture
What is the clinical presentation of an indolent ulcer?
-Ulcers on upper lip or orally
-Female cats (5-6 yrs. Age)
-No eosinophils
What is the clinical presentation of an eosinophilic plaque?
-Well circumscribed, raised, ulcerative plaque
-Abdomen, back, legs, head, neck
-Female cats (3yrs)
-Eosinophilic and mast cell infiltration
What is the clinical presentation of a linear granuloma?
-Linear tract on posterior aspect of hind limbs
-Severe cases can be seen in the oral cavity
-Either sex (1-5yrs)
-+/- Eosinophils
How would you identify an indolent ulcer?
-Histopath
-Hyperplastic ulcerative dermatitis w/ PMN, plasma cells, mononuclear cell infiltrate
-DDX
-Squamos cell carcinoma and Fibrosarcoma
How would you identify an eosinophilic plaque?
-Histopath
-Eosinophilic and Mast cell infiltrate
-Workup
-Biopsy
-Flea control***
-Hypoallergenic diet
-IDST
How would you identify a linear granuloma?
-Histopath
-Necrobiosis of collagen w/ histiocytic and multinuclear giant cell infiltrate +/- eosinophils
How would you treat an indolent ulcer?
-Identify and treat underlying cause
-Antibiotic trial
-Clavamox or Tribissen
-Systemic Corticosteriods
-Pred
-Depo-Medrol
REFRACTORY OR RECURRENT:
-CO2 laser
-Radiation treatment
-Cyrosurgery
-Immuno-stimulants (Levamisole or Thiabendazole)
How would you treat an eosinophilic plaque?
-Identify and treat underlying cause
-Elizabethan collar
-Antibiotics
-Corticosteriods
How would you treat a linear granuloma?
-Observation
-Identify and treat underlying cause
-Antibiotics
-Corticosteriods
-Immuno-stimulants
Describe the clinical presentation of feline plasma cell pododermatitis.
-Non-painful swelling of footpads that may ulcerate
Clinical Pathology:
-Hypergammaglobuinemia
-Lymphocytosis
-Neutrophillia
List the potential side effects of progesterone therapy.
-Hyperglycemia (leading to DM)
-Acromegaly
-Mammary hyperplasia (leading to neoplasia)
-Pyometra
-Infertility
-Behavioral changes
What is cyclosporine? What is its MOA in the treatment of atopy?
-Cyclosporine is an immuno-suppressive drug.
MOA:
-Suppresses T helper cells
-Decreases IgE production
-Decreases production of cytokines
-Overall decreases skin inflammation and itching
How is canine atopic dermatitis diagnosed?
-Must have at least 3 of the Major Criteria:
-Pruritis
-Typical morphology and distribution
-Involves face, feet, legs
-Seasonal or chronic dermatitis
-Family or breed predisposition
-Must have at least 3 of the Minor Criteria:
-Onset of symptoms <3 years of age
-Facial erythema and chelilitis (inflammation around lips)
-Bilateral conjunctivitis
-Superficial staph pyoderma
-Increased antigen specific-IgE
-Increased antigen-specific IgG4
-Immediate skin test reactivity
Is it possible to cure an atopic dog?
-No, just medically manage dog
-However, those animals treated w/ hyposensitization 25% may develop complete remission
What are the major causes of treatment failures in canine atopic dermatitis?
-Client compliance
-Don’t remove all possible environmental contaminants
-Don’t dose animals med’s correctly
What is the “flare factor” relating to atopy?
-The reaction that occurs in response to certain allergen
-Fleas are a big flare factor
Why is it important for owners to understand the concepts of summation of effects and pruritic threshold.
Summation of effects:
-It is the culmination of all things that can lead to the animals atopy problem
-If the owner can understand that there are a whole host of things that play a role in their animals atopy then maybe then can understand why treatment is so difficult and why they must play an active role in the process.
Pruritic Threshold:
-The level above which the animal will experience atopy
-Many factors contribute the animal exceeding the threshold
-For example: If fleas are the underlying cause and they are never treated, then the animal can never drop below the pruritic threshold
What are the causes and pathogenesis of food allergies?
Causes:
-Sudden reaction to a food source (usually one protein) that triggers an immunological response
-a lot are not IgE mediated
Patho:
-Food allergies can be either a Type I, III, IV hypersensitivity reaction
What is the best way to diagnose a food allergy
-The best way to diagnose food allergy is to do a restrictive diet trial
-Symptoms should subside off food (w/in at least 7 days)
-Challenges should be reproducible (onset, duration, clinical features)
-Symptoms should be gone after each withdrawal
What is an allergen? Antigen?
Allergen: an antigen that stimulates an IgE response (ex. Pollens, dust, animal dander, feathers)
Antigen: a substance that elicits an antibody response
How does contact hypersensitivity manifest in animals?
-Lesions usually occur in non-haired areas (feet, ears, ventrum, scrotum, chin, neck)
-Pruritis may be the only sign
-Severe cases: erythema, vesicles, ulcers, crusts, self-trauma
What are the differences between atopy and contact dermatitis?
Atopy:
-A familial predisposition to the development of IgE antibodies and clinical allergy to environmental allergens.
Contact dermatitis:
-Can either be allergic or irritant
Allergic Contact dermatitis:
-An inflammatory skin disease caused by a delayed (cell-mediated) response to an antigen or hepten. Requires repeated or continuous exposure to the substance
Irritant Contact Dermatitis:
-An inflammatory skin disease which occurs within minutes of contact w/ irritating substance
What are the common causes of contact hypersensitivity in dogs?
-Plant or plant pollen
-Molds
-Meds (neomycin, tetracain, shampoos, insecticides)
-Floor wax
-Polish or cleaners
-Dyes in rugs
-Carpets, blankets
-Rubber and plastic products
Will anti-histamine creams lessen inflammation in animals w/ contact hypersensitivity? What other treatments would you recommend?
-No anti-histamine are good are prevention, not a treatment once the animal is inflamed
Other treatments:
-Remove offending agent
-Bath after exposure
-Topical drying agents (Domeboro)
-Topical or systemic corticosteroids
-Pentoxiphylline
-Topical tacrolimus
What is miliary dermatitis?
-Variable pruritic papulocrustous eruption occurring over dorsum, head, and neck
-Millet seed lesions = hemorrhagic crusts
What approach would you follow in treating a cat w/ miliary dermatitis?
1. Flea control (if they respond, may be the only treatment)
2. Hypoallergenic diets
3. Skin biopsy
-Allergic = IDST
-Bacterial = C/S and TX
-Fungal = DTM and TX
-Pemphigus = DFA, TX
-Non-specific = Pred
-No response = Short term megesterol acetate
What is erythema multiforme?
it is an allergy, usually drug associated
How do you diagnose erythema multiforme?
-Physical Exam
-Clinical signs
How do you treat erythema multiforme?
-Removal of drug
-Possible corticosteroids??
What is toxic epidermal necrolysis?
full thickness coagulation necrosis of epidermis
How do you diagnose toxic epidermal necrolysis?
-Histopath
-full thickness coagulation necrosis of epidermis
How do you treat toxic epidermal necrolysis?
-Correct underlying cause
-Supportive care
-Pred (be careful there can be a high risk of sepsis)