A 55-year-old woman with a history of Grave disease and primary biliary cirrhosis presented with a photodistributed rash of 3 months' duration. Her medications at presentation included levothyroxine sodium, milk thistle, and vitamin E. Five weeks before the development of her eruption she had stopped taking ursodiol. Physical examination demonstrated malar erythema, violaceous periorbital edema, and juicy erythematous plaques in a photodistribution on her arms and neck (Figure 1). Cuticular overgrowth and splinter hemorrhages were also noted. Her strength was normal. Before presentation, her laboratory tests revealed the following elevated liver enzyme levels (to convert values to microkatals per liter, multiply by 0.0167): alkaline phosphatase, 670 U/L (reference range, 20-125 U/L); aspartate aminotransferase, 86 U/L (reference range, 2-35 U/L), and alanine aminotransferase, 74 U/L (reference range, 2-40 U/L). Her erythrocyte sedimentation rate was also elevated at 48 mm/h (reference value, <30 mm/h). The results of a thyroid function panel, basic metabolic profile, complete blood cell count, and antinuclear antibody titer were within normal limits. Two punch biopsy specimens revealed similar findings that included a superficial and middermal perivascular and focally diffuse infiltrate composed almost entirely of mature neutrophils with occasional scattered lymphocytes and rare eosinophils (Figure 2). Dermal edema was noted. Leukocytoclasis and vascular fibrin were not present. A periodic acid–Schiff stain was negative for fungal elements. Further laboratory studies were negative for anti-Ro (SS-A) and anti-La (SS-B) antibodies, rheumatoid factor, and anti-native DNA antibodies. The creatine kinase level was normal, but the aldolase level was elevated (12.2 U/L [to convert to microkatals per liter, multiply by 0.0167] [reference range, 1.2-7.6 U/L]). Serum protein electrophoresis revealed elevated levels of polycolonal IgG, consistent with a chronic inflammatory response. The results of urine protein electrophoresis were negative, and complement levels were within normal limits. The patient was started on a regimen consisting of a methylprednisolone dose pack, fluticasone propionate cream, 0.05%, at night, and tacrolimus ointment in the morning. Her rash persisted, and 1 month later, biopsy specimens were obtained from the posterior aspect of her neck and from the lower midback area. The specimens revealed diffuse infiltrates of mature neutrophils admixed with neutrophil dust, rare eosinophils, and mild papillary dermal edema. Two months after the patient's initial presentation, oral dapsone therapy (25 mg/d) was initiated, and a slight improvement was seen within 3 weeks. When the dosage was increased to 25 mg twice a day, the lesions resolved; however, when the dapsone therapy was discontinued after 8 months, the eruption recurred but again responded after the dapsone therapy was reinitiated.