A 41-year-old woman presented to the dermatologist with a 3-week history of painful oral ulcerations and inguinal adenopathy on the right side. In addition, she noted a mild, asymptomatic skin eruption on the extensor surface of her forearms. A review of systems was negative, including the absence of arthralgias and photosensitivity.
Physical examination revealed a well-developed woman with numerous oral erosions (Fig 1). There were faint, illdefined erythematous scaling areas over both extensor forearms. Painful right-sided inguinal lymphadenopathy was present. Because of the sparing of the alveolar mucosa, an autoimmune cause of the ulcers was suspected.
Initial laboratory findings included a white blood cell count of 3.8×109/L, an erythrocyte sedimentation rate of 44 mm/h (normal, 0 to 20 mm/h), C3, 15 mg/dL (normal, 83 to 177 mg/dL); C4, 3 mg/dL (normal, 15 to 45 mg/dL), single and double-stranded DNA, positive; and antinuclear antibody, positive at 1:641 (speckled). Pertinent negative findings