Allergen specific IgE determination by in vitro allergy test in head and facial feline dermatitis: A pilot study

Pruritus is one of the most common clinical findings in cats which have hypersensitivity on head and face regions. The purpose of this small pilot study was to verify underlying causes of pruritus in cats with head and facial dermatitis by using in vitro Veterinary Polycheck allergy tests which specifically detect Immunoglobulin E (IgE) concentrations against 20 different allergens. Ten cats were introduced to the clinic with varying degrees of head and facial dermatitis along with primary/secondary skin lesions and pruritus. At first, haematological, parasitological, microbiological and clinical examinations were performed. Six healthy cats without dermatitis (neither infection nor hypersensitivity) were also evaluated as a control group. Afterwards, 0.2 ml of blood was taken from all cats for specific IgE analysis against 20 different allergens. Regarding allergen specific IgE levels (kU/l) in cats with head/facial dermatitis and in healthy cats, in vitro tests gave a positive reaction most frequently against flea, Acarus siro, D. farinae, Ragweed (Ambrosia), Lambs quarter and Tyrophagus. There was a statistical significance between two groups for all allergens as follows; Lepidoglyphus (p=0.031), Alternaria/Cladosporium (p=0.011), Stinging nettle (p=0.011) Lambs quarter (p=0.031), Sorrel (p=0.003) and flea (Ctenocephalides) (p=0.031). In the present study, all positive reactions on the Polycheck test were thought to indicate underlying allergens of facial/head dermatitis in cats. It has to be mentioned that, in vitro allergy tests cannot be used as a sole method for distinguishing hypersensitivity from healthy cats due to the clinically irrelevant findings regarding morphology in healthy cats. Positive reactions in healthy cats might indicate a subclinical hypersensitivity state or the requirement for investigating other relevant factors.