Feline Atopic Syndrome: the current need for a multimodal diagnostic approach

Abstract

Background Clinical signs of Feline Atopic Syndrome rely mainly on the presence of pruritus, like in dogs. Despite, in cats, specific patterns of skin reaction could point to a primary allergic cause of the atopic syndrome, these patterns are not specific of atopy. Factors such as ectoparasites, food or environmental allergens may also trigger a great diversity of close clinical signs.

Etiologic and pathogenic diagnosis of FAS requires time and dedication, and both the veterinarian and the owner should cooperate. Since none of the clinical signs or global presentation pattern result pathognomonic for FAS, and no “perfect” diagnostic test is still available, a combination of i) suggestive anamnesis; ii) clinical signs and iii) exclusion of other compatible differentials stand so far as the most reliable diagnosis plan. Hence, in face of a compatible clinical history of SAF it is necessary to proceed through a detailed collection of patient´s relevant information and to carry out several complementary diagnostic exams as skin cytology and/or histology, trichograms, bacterial and fungal cultures, among others.

Throughout the current plan leading to a positive diagnosis of FAS, several differentials are successively discarded. However, mostly due to pruritic consequences, several skin complications may join the clinical frame, making difficult either the diagnosis or even the treatment options.

Evolution of the clinical condition following the implementation of allergen-avoidance measures also plays a crucial role in the diagnosis confirmation as Feline Dermatitis Extent and Severity Index (FeDESI) or Scoring Feline Allergic Dermatitis (SCORFAD) may evolve positively regarding the avoidance of implicated allergens species.

Methods Three clinical cases of FAS are described, exemplifying the current multi-modal diagnosis approach. Each of them presented with a distinct, not pathognomonic clinical pattern: #1 self-induced alopecia; #2 eosinophilic skin lesions and #3 head and neck excoriations. Diagnosis of FAS was obtained by differential exclusion, combining anamnesis, clinical signs, dermatology complementary tests, prophylactic flee prevention and exclusion diets.

Results All of the patients presented with FAS and #2 and #3 also with secondary pyoderma; #3 also with ceruminous external otitis, a not so common manifestation in cats with FAS, needing specific treatment.

Conclusion FAS positive diagnosis allowed effective control of clinical signs with significant gain in wellbeing.