Cutaneous Xanthomas With Concurrent Demodicosis and Dermatophytosis in a Cat

In a 9-month-old domestic longhaired cat, multiple cutaneous xanthomas associated with fasting hyperlipidemia were reported. The cat initially presented with a severely pruritic, papular, and crusting dermatitis on the head and neck, which was initially misdiagnosed as eosinophilic granuloma complex. Treatment with prednisolone and chlorambucil controlled the pruritus, but repeat histological examination revealed cutaneous xanthoma and mild demodicosis. The cat also had marked fasting hypercholesterolemia, hypertriglyceridemia, and transient hyperglycemia. A low-fat diet and oral milbemycin were initiated, leading to a gradual regression of skin lesions, although pruritus recurred with reduced immunosuppressive treatment. Microsporum canis was isolated from hair samples, and the addition of griseofulvin to the treatment resolved all cutaneous lesions. The cat also suffered from corneal ulceration and keratoconjunctivitis sicca, which resolved with treatment including topical cyclosporin. Diabetes mellitus developed 6 months after the skin lesions resolved, but no cutaneous or ocular abnormalities were noted 6 months later with continued low-fat diet and insulin treatment, despite a transient recurrence of papules and pruritus after eating a fatty meal. The case suggested an underlying primary hyperlipidemia causing pruritic xanthomas, and may be the first report of concurrent cutaneous xanthomas, demodicosis, and dermatophytosis in a cat.