Pemphigus foliaceus (PF) is an immune-mediated disease that causes pustules and crusted lesions, most commonly on the pinnae, nasal planum, periocular area, chin, feet of affected cats. Acantholytic cells caused by dehydration of intercellular adhesions are often seen on cytology but are not pathognomic for PF. A definitive diagnosis is made based on histopathology showing subcorneal pustules with nondegenerate neutrophils and acantholytic cells. PF is treated with immunosuppressive doses of corticosteroids alone or in combination with other immunosuppresive medications, such as chlorambucil or cyclosporine. Most patients require lifelong treatment with these medications to keep the disease in remission.
Hershey, a 6-year-old, spayed domestic shorthaired cat weighing 3.4 kg, presented with an acute onset of nonpruritic crusted lesions on the head, ears, nail beds, and nasal
area. She had a 2-day history of lethargy and anorexia. She had no history of medical disease and was up-to-date on vaccinations.