A 15-year-old cat was presented for excessive grooming, hair loss, and scaling of 9-months duration. The cat had been previously healthy except for excessive inappropriate urination, a prior perineal urethrostomy, periodontal disease, and recurrent respiratory disease. On examination, the cat was thin, dehydrated, and unkempt. The owner reported generalized pruritus and hair loss over most of the body. Thick scaling, dull coat, rancid odor, and focal areas of hyperkeratosis were also noted. Marked accumulation of waxy debris was noted on planum nasale, nail beds, abdomen, and ear tips. Laboratory evaluation included a CBC, serum chemistry panel, thyroid hormone concentration, FeLV and FIV testing, and urinalysis. Prerenal azotemia and anemia of chronic disease were the only major abnormalities found. Skin scrapings were negative for mites, and cytologic skin evaluation showed large numbers of bacteria and yeast. Skin biopsies revealed a surface crust, thickened epidermis, acanthosis, parakeratosis, and marked perivascular neutrophilic infiltration with eosinophils. There was also edema in the dermis. The presence of acanthosis and parakeratosis with occasional apoptotic keratinocytes in the basal layer was most suggestive of paraneoplastic disease. An extensive medical workup failed to identify neoplasia. The disorder responded temporarily to oral antibiotics, oral itraconazole, and topical ketoconazole shampoo before the cat was euthanized for unrelated reasons.
COMMENTARY: Feline paraneoplastic syndrome is not a "new" disease but rather a skin condition that has been recently identified as a cutaneous marker of systemic illness. It has been reported most commonly in cats with neoplasia, particularly of the pancreas or bile duct. The author has seen 2 "typical" presentations. The first is marked telogen effluvium with easily epilated hairs. The cats have widespread noninflammatory alopecia, and the skin is shiny. The second is characterized by more extensive inflammation with crusting and scaling and hair loss and often marked secondary yeast accumulation as described above. Feline paraneoplastic skin disease should be considered in cats presented with signs of systemic illness, such as fever, weight loss, anorexia, lethargy, vomiting, diarrhea, and marked skin disease. Shiny skin is a helpful sign but is not present in all cats.
Diagnostic dermatology: Paraneoplastic syndrome. Hall J. Can Vet J 48:203-204, 2007.