Eosinophilic Plaque in Cats

Eosinophilic plaque is a type of inflammatory skin lesion that can develop in cats, typically appearing as raised, moist, red areas that often have a raw or eroded surface. The name reflects the presence of a specific type of white blood cell (eosinophils) that accumulates in the affected tissue. These lesions are part of a broader pattern sometimes called the eosinophilic granuloma complex, though the plaque form has its own characteristic appearance and behaviour. Owners most commonly notice eosinophilic plaques as distinct, slightly raised patches on the skin—often on the belly or inner thighs—that may look angry or ulcerated, and which the cat may lick persistently. The lesions can appear suddenly or develop gradually, and their appearance tends to prompt questions about whether the cat has been injured, bitten, or has developed an infection. In many cases, the affected area is intensely itchy, which drives the licking behaviour. This page explores what eosinophilic plaques can look like when they first appear, what processes underneath the skin may be driving them, how they are investigated to understand the cause, and what approaches exist for managing them. The underlying trigger varies between individuals and can include reactions to allergens, parasites, or other factors that provoke the immune response in the skin.