Image courtesy Dr Kate - the Cat Vet
Feline perforating dermatitis (feline acquired reactive perforating collagenosis) is a rare clinical presentation characterised by pruritic lesions containing single or multiple papules and plaques, containing a central, firm, exophytic, cone-shaped, yellow-orange keratotic plug, tightly adherent to the underlying skin.
Removal of the protruding material is usually associated with bleeding, leaving the ulcerated surface exposed.
Histopathologically, the diagnosis is straightforward because of the presence of vertically orientated collagen bundles extruded from ulcerated, concave-shaped invaginations of the skin.
In two cases, vitamin C administration failed to resolve the disease. In two cases, methyl-prednisolone acetate was used to manage relapsing episodes and vitamin C helped to reduce glucocorticoid requirements. In one case, treatment with methyl-prednisolone acetate only appeared to be curative. The fourth case was lost to follow-up immediately after the diagnosis.