A 72-year-old man with a purpuric rash A 72-year-old man whose medical history includes diabetes mellitus, hypertension, coronary artery disease, aortic valve replacement, atrial fibrillation, and chronic obstructive pulmonary disease was in his usual state of health until 2 weeks ago, when he developed a purpuric rash on his legs. His physician started him on prednisone 40 mg daily for the rash; however, 1 week later he presented to a hospital emergency room when his family found him confused and diaphoretic. In the emergency room, he was found to be hypoglycemic, with a serum glucose level of 40 mg/dL, which was promptly treated. His mental status improved partially. In the hospital, the rash worsened and progressed upwards to his trunk and upper extremities. He was transferred to our institution for further workup and management. A review of systems reveals occasional epistaxis in the summer, recent fatigue, cough, and shortness of breath on exertion. His medications at the time of transfer include warfarin (Coumadin), amlodipine (Norvasc), insulin, ipratropium and albuterol (Combivent) inhalers, and prednisone 40 mg daily. He has not undergone surgery recently. Physical examination ■ He is alert and oriented to person but not to time and place. Vital signs. Oral temperature 101.1°F (38.4°C), pulse rate 108, blood pressure 108/79 mm/Hg, respiratory rate 22, oxygen saturation 93% by pulse oximetry on room air, weight 94 kg (207 lb). Head, eyes, ears, nose, and throat. No pallor or icterus, pupils are equally reactive, nasal mucosa not inflamed or ulcerated, mucous membranes moist, no sinus tenderness. Neck. No jugular venous distention and no cervical lymphadenopathy. Cardiovascular. Tachycardia, irregularly irregular rhythm, prosthetic valve sounds, no murmurs, rubs, or gallops. Respiratory. Bibasal crackles (right side more than the left). No wheezing. Abdomen. Soft, nontender, nondistended, no palpable organomegaly, bowel sounds normal. Extremities. No edema, good peripheral pulses. Skin. Diffuse, nonblanching, petechialpurpuric rash (FIGURE 1) with scaling on both legs and extending up to the abdomen, flanks, chest, and both arms.