5. Atopy, Flea allergy, Food sensitivity

Question 1

What does atopy mean?

Answer 1

An exaggerated production of IgE immune response against otherwise harmless substance in the environment

Question 2

What is atopic dermatitis?

Answer 2

A genetically determined chronic pruritus dermatitis

Question 3

What is atopic dermatitis sensitive / have a predisposition for?

Answer 3

Developing an immediate type I hypersensitivty to specific allergens

Question 4

What is one of the most common causes for development of chronic recurring inflammatory skin disease?

Answer 4

Atopic dermatitis:
Involving complex interactions of
- environmental
- genetic
- microbial
- immunological
- pharmacological factors

Question 5

What are the general age predisposition in atopic dermatitis?

Answer 5

Between 6months - 3 years
BUT there is a great variability so should not be ruled cause of age.

Question 6

Mention a few breeds which are predisposed for atopic dermatitis

Answer 6

Golden-, Labrador retriever, Beagle, Dalmatian, Cocker Spaniels. French Bulldogs

Question 7

What are 3 typical signs of atopy?

Answer 7

• Atopic dermatitis - one of most typical signs. Other two sometimes occur and not always together
• Atopic rhinitis
• Atopic conjunctivits

Question 8

What are the forms of atopic dermatitis and what do they mean?

Answer 8

External form - Production of IgE
Internal form - Without production of IgE

Question 9

Name a few intrinsic factors that can influence onset of dermatitis

Answer 9

• Genetical predisposition
• Immune response
• Specific features of skin barrier hydrolipid barrier which pathogens can have an affinity for.

Question 10

Name a few extrinsic factors that can influence onset of dermatitis

Answer 10

• Mites
• Mold spores
• Pollens
• Epithelial cells of different species that can act as a provoking allergen: Food allergens is seen in about 30% of atopic dogs and Pseudointermedius or Malassezia spp.

Question 11

What are clinical signs of atopic dermatitis and where on the body are the distributed?

Answer 11

Most commonly presented as
- pruritus
- erythema
- secondary microbial infections (Staphy. or Malassezia pachydermatis frequent findings in atopic dermatitis)
- papules (very small 1mm)
- Otitis externa (seen in 4/5 cases)

Pruritus and lesions typically involve:
- face
- around eyes
- lateral ear plot (concave ear)
- ventral abdomen
- perianal regions
- interdigital areas
- Lateral symmetry is common.

Question 12

What are clinical signs of atopic dermatitis in CATS?

Answer 12

• Facial or ear pruritus
• Miliary dermatitis
• Eosinophilic granuloma complex (granuloma, ulcer plaque)
• Symmetrical alopecia
• Generalized pruritus

Question 13

How many criterias should be fulfilled for diagnosis of atopic dermatitis?

Answer 13

5 to confirm atopic dermatitis

Question 14

How can we diagnose atopic dermatitis?

Answer 14

NR 1 - According to history
But also according age, breed, recurrent infections, if any concomitant signs as AR, AC (typical signs of atopy) and seasonability

1. In vitro diagnostic - Easier and more reliable. Polyclonal Ab for detection of allergen specific IgE in serum
2. Intradermal skin test

Question 15

What are differential diagnostics to keep in mind before diagnosis with atopic dermatitis?

Answer 15

• Sarcoptic mange - similar to atopy and has to be ruled out before with skin scraping and treatment
• FAD
• Bacterial pyoderma
• Malassezia dermatitis
• CAFR (Cutaenous Adverse Food Reactions)
• Demodicosis

Question 16

How is atopic dermatitis treated?

Answer 16

There is no cure and the condition needs a life long management as a combination of treatments

• Allergen specific immunotherapy by application of allergen extracts in arising levels by skin test or serology – causing a modulation of suppressor and T-helper cells and a shift of immune response, in 60-80% its effective in young dogs.
• Antihistamines – Not as effective in dogs as in humans but can be given to patient with not so bad pruritus.
• Glucocorticoids – Methylprednisolone. Only used in cats since showing less side effects than dogs.
• Oclacitinib – Recommended for allergy, atopy, flea dermatitis. Good drug to stop it quickly. Not so common with side effects and drug of choice many times. Give 0,4 – 0,6mg/kg x2 a day for 14 days P.O, then 1 tablet a day. Very effective already after one pill.
• Lokivetmab – caninised monoclonal Ab targeting IL-31. Decreases pruritus and inflammation in body. Very effective. Given S.C. In patients up to 1 year and less than 2kg it is not used as antiallergic treatment and instead corticosteroids.
• Essential fatty acids – Used as supportive treatment in combination with antihistamine to enhance the effect, long term treatment. Effective to leukotrienes and prostaglandin synthesis – changing skin lipids and modulation of lymphocyte function.

Question 17

What is flea allergy?

Answer 17

• Combination of type I and IV hypersensitivity reaction.
• No breed disposition
• Can be trigged by presence of only one fly

Question 18

What is the age predisposition of flea allergy?

Answer 18

Develop usually between age 3 - 6 years old

Question 19

What are clinical signs of flea allergy?

Answer 19

Popular-crust lesions

• Often found on tail, on lumbosacral regopin
• In chronic course can se HYPERPIGMENTATION

Question 20

What type of hypersensitivity is food hypersensitivity?

Answer 20

Type I hypersensitivity (allergy)

Question 21

What type of hypersensitivity is contact dermatitis and why does it occur?

Answer 21

• Hypersensitivity type IV (allergy)
• Sensitivity induced by bacteria, viruses, chemical substances parasites, that bind to body proteins and thus form new antigens that are responsible for skin reaction.
  *The slow reaction occurs in 24 – 72h.