A 24-year-old man with extensive lower limb edema and acute arterial occlusion.

A 24-year-old man was admitted to Lyndon B. Johnson Hospital, Houston, with the chief complaint of severe pain of the left leg associated with cyanosis and blistering of the toes. He had been well until 10 days before admission. In the intervening time period, he developed gradual swelling of both legs that extended up to the mid thigh bilaterally. He also noticed mild dyspnea. On the day before admission, he reported bluish discoloration of the toes of the left foot. He also began to experience severe pain in the left lower leg and noticed blistering of the dorsum of the foot several hours before coming to the hospital. On admission, the patient denied any past medical problems. He reported having been treated with antibiotics for pneumonia 1 month earlier. He was not taking any medications other than a diuretic that had been prescribed 1 week earlier. There were no family medical problems. He denied use of tobacco, illicit drugs, or alcohol. Clinical examination revealed a robust young black man with respiratory distress, mild pallor of mucous membranes, and a temperature of 99.3°F. There was bilateral pitting edema of the lower limbs to the mid thigh. The left leg below the knee was cool and cyanotic. The left popliteal artery and dorsalis pedis pulses were not palpable. There were two large blisters over the dorsum of the left foot. Cardiovascular examination showed a pulse rate of 124 beats per minute; all pulses were present except for pulses below the left knee. The blood pressure was 113/60 mm Hg in both the right and left upper limbs. The jugular venous pressure could not be evaluated. The first and second heart sounds were normal; a low-pitched diastolic sound of uncertain origin was heard. A few crackles were heard at the lung bases bilaterally. The abdominal examination was unremarkable except for mild tenderness in the right upper quadrant; the liver and spleen were not palpable. The rectal examination was normal, and the guaiac test was negative. The patient was alert and oriented, and the