Abstract
We present a 57-year-old female with a past medical history of rheumatoid arthritis, hypertension, and hypothyroidism who presented with poorly demarcated, nonblanching, painful, erythematous nodules on the bilateral lower legs for two weeks. The patient recently switched from infliximab to abatacept infusions, and skin eruptions presented 53 days from her initial abatacept infusion. A 5 mm punch biopsy of the left anterior upper leg in the zone of involvement showed a deep dermal granulomatous infiltrate with associated eosinophils and a vaguely horizontally palisaded pattern with necrobiosis. The granulomatous inflammation extended into the subcutaneous septae with a widening of the septae, edema, and lipomembranous fat necrosis. The patient was started on naproxen 500 mg PO BID and halobetasol propionate 0.05% lotion BID. Concomitantly, she was started on a four-day course of oral prednisone 10 mg PO daily and restarted infliximab infusions on the third day of prednisone treatment. At her initial infliximab infusions, she received one dose of solumedrol 40 mg and diphenhydramine 50 mg. The eruption resolved 21 days after the initial presentation. The present case is unique from the nine other cutaneous eruptions described after initiating abatacept therapy. Less than 10 cases of cutaneous panniculitides have been reported as adverse reactions to abatacept, with the most common reactions associated with oral contraceptives, nonsteroidal anti-inflammatory drugs, antibiotics, and leukotriene modifying agents. This case underscores the variety of histological findings in drug-induced panniculitis, highlighting the possibility of a drug reaction in a patient with rheumatological disease presenting with panniculitis.