Rarely, transformation to squamous cell carcinoma may occur. Eosinophilia is rare, both on CBC and in the biopsied tissue. Usually on the abdomen or medial thighs. Lesions may be single or multiple. Plaques are well-circumscribed, raised, round to oval, red, oozing, often ulcerated, and up to 7 cm in diameter.
Lesions usually are severely pruritic.
Histologic evaluation will reveal eosinophils and superficial and deep perivascular dermatitis. Peripheral eosinophilia is common on CBC evaluation. More common in young cats. Usually on the caudal thighs, the face, or in the oral cavity. On the caudal thighs, the lesions are well-circumscribed, raised, firm, yellow to pink plaques with a characteristic linear shape.