Underlying causes of erythema nodosum - Lesions may provide clue to systemic disease

A 38-year-old woman presented with a 2-week history of tender, swollen nodu les on her lower legs (figures 1 and 2). She stated that similar swellings had appeared several years earlier, when she was pregnant, and resolved wit hout treatment after several months. Her only current medication was a trip hasic oral contraceptive. She denied any history of inflammatory bowel dise ase, sarcoidosis, or chronic infections. She also denied exposure to iodide s, bromides, or sulfonamides. Physical examination revealed erythematous nodular swellings on the anterio r lower legs. The lesions were 1 to 4 cm in diameter and tender to palpatio n. A 4-mm punch biopsy specimen was obtained from a lesion on the left ante rior tibia. Examination revealed a septal inflammation of subcutaneous fat characteristic of erythema nodosum. Treatment consisted of clobetasol propionate 0.05% cream, applied to affect ed areas twice a day, and nabumetone, 500 mg twice daily. In addition, the patient was told to discontinue oral contraceptives, elevate her legs, and apply warm, moist compresses. The nodular swellings disappeared in 3 to 4 w eeks with no complications, and there were no recurrences at follow-up exam ination 3 months later.