Atopic dermatitis

Question 1

Definition of atopic Dermatitis

Answer 1

common skin disorder defined as a hereditary predisposition to develop pruritic inflammatory skin disease associated with IgE antibodies, which typically target environmental allergens

Question 2

Typical age of animals presented

Answer 2

6mnts to 3yrs

Question 3

Typical pattern of pruritus and secondary lesions

Answer 3

Around the face (mouth, eyes), concave aspect of the ear pinnae, ventral abdomen, flexor aspects of elbow, carpal, and tarsal joints, interdigital skin, and perineal area

Question 4

Progression of disease

Answer 4

Initially it is just pruritis which then develops into secondary lesions

Question 5

What is the pathogenesis of Canine Atopic dermatitis

Answer 5

Complex and poorly understood but a combination of:

• sensitisation to environmental/food allergens
• poor skin barrier function
• genetic predisposition

Question 6

Which breeds are predisposed?

Answer 6

Bull terrier 
Shar-pei 
Frenchie 
Westie 
Golden or Labrador retrievers 
GSD 
Boxers

Question 7

What are Favrot’s criteria and why is it useful?

Answer 7

Criteria

• Onset of signs under 3 years of age
• Dog living mostly indoors
• Glucocorticoid-responsive pruritus
• Pruritus sine materia at onset (ie, alesional pruritus)
• Affected front feet
• Affected ear pinnae
• Nonaffected ear margins
• Nonaffected dorsolumbar area

When 5/8 are for-filled then there is 80% specificity/sensitivity i.e. it is good but not as a sole diagnostic tool

Question 8

Other diagnostic tools

Answer 8

Exclusion of other pruritic disease (parasites, microbes, FAD)

• make sure on good antiparasiticde and environmental control
• Skin scrapes, coat brushing, cytology
• Check for secondary Staph/malessezia

Question 9

First steps in management of disease

Answer 9

1. Identifying and addressing (or, if possible, avoiding) the associated flare factors
2. Using a topical and/or systemic treatment to decrease inflammation and pruritus

Question 10

what are some flare factors for CAD?

Answer 10

Skin disease:
FAD
Food related

Question 11

How would you manage skin disease?

Answer 11

• recurrent ear and skin infections with Staphylococcus and Malassezia species = topical once- to twice-weekly therapy using antimicrobial shampoos (eg, chlorhexidine, benzoyl peroxide, miconazole, ketoconazole)
  In severe cases consider systemic drugs

Severe Pyoderma
Cephalexin, cefadroxil 15-30 mg/kg PO q12h
Cefpodoxime 5-10 mg/kg PO q24h
Clindamycin 5.5-11 mg/kg PO q12h
Lincomycin 15-25 mg/kg PO q12h

Severe Malasseziadermatitis
Ketoconazole 5-10 mg/kg q24h
Itraconazole 5 mg/kg q24h for 3 weeks
Terbinafine 30 mg/kg q24h for 3 weeks

Question 12

How would you manage Food related flare ups?

Answer 12

• food related CAD flare ups are typified by non-seasonal and potentially additional GIT signs
• management = novel protein then rechallenge to ID specific cause

Question 13

How do you carry out a diet trial?

Answer 13

1) give strict diet of 6-10 weeks of novel protein.
2) During the first 6 weeks resolve existing pruritis and inflammation with symptomatic treatment.
3) . Wait for 3 weeks
- If C/S return on novel diet after discontinuing symptomatic Tx then we can conclude it is not food related.
- If C/S do not return then rechallenge with old diet to confirm after 3 weeks.

Question 14

Management of environmental allergens, two methods to do so?

Answer 14

1) . reduce exposure
- Dust mites and pollens are #1 cause in dogs.
- Arcosan spray is licensed to reduce number of dust mites and reduce CAD C/S
- Regular vacuuming and washing

2) . Allergen Immunotherapy (AIT)
- do Allergen testing
- Only 60% effective and can take 9months to work

Question 15

What drugs are used best to get CAD under control (short term)?

Answer 15

• Oral/topical glucocorticoids
• Oclacitanib (Apoquel)
• Cytopoint
  (- Surgery…)

Question 16

What drugs are best to manage CAD in long term?

Answer 16

• Oral/topical glucocorticoids
• Cyclosporin
• Oclacitanib (Apoquel)
• Cytopoint