Vegetative Plaques and Hemorrhagic Pustules

Abstract

A man with a history of chronic renal insufficiency (baseline creatinine level, 2.8mg/dL) presented for evaluation of a painful forehead erythematous eruption and associated headache. (To convert creatinine to micromoles per liter, multiply by 88.4.) Three days prior to symptom onset he underwent a contrast-enhanced computed tomographic (CT) scan to evaluate abdominal pain. On the central forehead was a tender 5-cm reddish brown plaque composed of numerous coalescing vesicles and hemorrhagic pustules with intermixed serous and hemorrhagic crust. Similar vesicles and pustules were present on the nasal bridge and tip, the bilateral conchal bowls, and on the scalp (Figure, A). Two days later, the patient developed several 0.5to 1.0-cm purpuric macules and hemorrhagic vesicles on the bilateral hands and nail beds. Initial blood tests revealed a white blood cell count of 6400 cells (range, 4000 to 11 000/μL; to convert to ×109/L, multiply by 0.001). The patient denied any new medications, any known contacts with or exposures to individuals who were ill, and any history of skin disease. A punch biopsy of the forehead plaque was performed (Figure, B and C). What is your diagnosis?