A 9-year-old castrated male Persian cat was referred with a four-month history of non-pruritic crusting and alopecia involving
the face and abdomen.
The cat did not respond to previous treatment with repositol methylprednisolone acetate (20 mg), amoxicillin, cefadroxil and
Physical examination revealed no abnormalities other than skin disease. Symmetrical, multifocal alopecia with crusting was
present on the face, ears, neck, ventrum and distal limbs. The crusted and alopecic lesions on the face were symmetrical,
well-demarcated and arranged in a confluent periocular pattern extending to the dorsal aspect of the head and the dorsum of
the muzzle. The medial and lateral surfaces of the pinnae were affected mildly. The planum nasale, peri-oral region and oral
cavity were spared. The digital paw pads of all feet were moderately crusted.
Differential diagnoses for these skin lesions included pemphigus foliaceus, systemic lupus erythematosus, discoid lupus erythematosus,
dermatophytosis, demodicosis, superficial pyoderma, keratinization disorder, sebaceous adenitis, drug eruption.
A complete blood count (CBC), biochemistry profile, urinalysis, antinuclear antibody test (ANA), dermatophyte culture, deep
skin scrapings and multiple skin biopsies were performed. Blood work revealed anemia compatible with chronic disease and thrombocytopenia
of 35,000. Skin biopsy specimens taken from the ventral abdomen and face were fixed in 10 percent neutral buffered formalin
and revealed interface dermatitis and interface folliculitis (inflammation involving the follicular-dermal interface) comprised
primarily of lymphocytes, mast cells and fewer neutrophils. These findings were considered suggestive of lupus erythematosus.
Results of the dermatophyte culture were negative.
The cat fulfilled only three criteria established by the ARA for the diagnosis of human SLE (facial dermatitis, thrombo-cytopenia
and a positive ANA). Based upon the clinicopathological findings a tentative diagnosis of systemic lupus erythematosus was
Prednisone was prescribed at a dosage of 10 mg orally twice daily.
One month after therapy was initiated, the crusting on the face, although still evident, was markedly diminished. In addition,
hair was beginning to regrow in previous areas of alopecia. The CBC revealed thrombocytopenia of 75,000. Owing to the presence
of persistent thrombocytopenia and only a modest increase in the PCV, chlorambucil therapy was recommended but was refused
by the owner. Therefore, prednisone therapy was continued.
Two-hundred and twenty-five days after prednisone therapy was initiated and three months after decreasing the prednisone dosage
to 10 mg every other day, the owner stopped administering the prednisone. The cat was returned to the hospital 10 days later
when the owner noticed blood oozing from the mouth.
Moderate, multifocal crusting and alopecia were present on previously affected areas and was consistent with a relapse of
SLE. In addition, a deep bleeding ulcer, measuring 3x5 mm, was present on the hard palate. Surgical ligation of the palatine
artery was required to stop the hemorrhage.
Administration of chlorambucil was again recommended, but the owner declined. Prednisone was re-initiated. Ultimately, clinical
remission was maintained again with a dose of 10 mg every other day. The cat has remained clinically normal two years after
initial diagnosis receiving the same dosage of prednisone. Adverse effects from corticosteroids have not been evident to date.
Systemic lupus erythematosus was diagnosed in this cat based upon the presence of facial dermatitis, anemia, thrombo-cytopenia,
positive ANA, oral ulceration and supportive skin histopathology. The cat fulfilled four of 11 ARA criteria that included
thrombocytopenia, positive ANA, facial dermatitis and oral ulceration. Although a biopsy of the palatine ulcer was not performed,
the ulcer was thought to be attributable to SLE and was considered the fourth ARA criteria for diagnosis of SLE.
The American Rheumatism Association requires a human patient to meet four of 11 criteria to diagnose SLE. The most common
findings observed in humans with SLE include malar rash (face), photosensitivity, fever, arthritis, serositis, nephropathy
and neurological disease. Some human patients do not meet these established criteria and may ultimately develop additional
signs months to years after initial examination.
Our cat fulfilled four of 11 criteria; however, sparse literature exists concerning the diagnosis of feline SLE, making correlation
between human SLE and feline SLE difficult.