Retiform purpura caused by the use of cocaine, that was probably adulterated with levamisole.

Abstract

Dear Editor: Retiform purpura is a dermatological condition characterized by reticulated, stellate, or serpentine shaped purple lesions on the skin and mucous membranes. New, multiple cases of retiform purpura after the use of levamisole adulterated cocaine have been reported. Levamisole is an anthelmintic drug with immunomodulatory and immunostimulating properties. It has been used in humans to treat rheumatoid arthritis, cancer of the colon and nephritic syndrome in children. It was withdrawn from use in the United States in 2000 because of the risk of agranulocytosis1. We report the case of a 52-year-old woman receiving treatment with levothyroxine for hypothyroidism. Two days after consuming cocaine, she developed painful skin lesions with arthralgia on both wrists. Physical examination revealed plaques and papules infiltrated to touch, purpuric on the edges and necrotic in the center, with reticular and stellate lesions on both cheeks, the tip of the nose, outer left ear, and lower limbs (Fig. 1). Biopsy revealed thrombotic vasculopathy of the small and medium blood vessels in the dermis and subcutaneous cell tissue (Fig. 2). Blood tests revealed leukopenia, neutropenia, and lymphopenia. Antinuclear antibodies (ANA, titer 1 : 1.280) in anti-neutrophil cytoplasm antibodies (ANCAs) against myeloperoxidase with a p-ANCA pattern (titer, >100 [0~5]), and ANCAs against proteinase 3 with a c-ANCA pattern (titer, 6.8 [0~5]) were also found. Hypocomplementemia of C3 was detected. The tests for thrombosis and coagulation, serology, cryoglobulins and antiphospholipid antibodies were normal or negative. Cocaine was detected in the urine sample. The results of chest radiography and urine sediment test were normal. A diagnosis of retiform purpura resulting from the use of cocaine, that was probably adulterated with levamisole was made. She was prescribed with low dose oral prednisone. The hematological symptoms cleared 5 days later, after one month, the skin lesions had healed without sequelae. Fig. 1 (A) A reticular plaque with purpuric edges and necrotic center on the left cheek. (B) Reticular and stellate plaques with purpuric edges and necrotic center on low limbs. Fig. 2 Hematoxylin-eosin staining image (×10) showing thrombotic vasculopathy of the small and medium blood vessels in the dermis and subcutaneous cell tissue. Levamisole is currently only used in veterinary medicine as an anthelmintic; however, it has recently begun to be used as an adulterant in cocaine in many countries, including Spain2. Levamisole poisoning should be suspected in the case of a young patient presenting bilateral cutaneous necrosis on the earlobes, cheeks, or nose, that may be accompanied with retiform purpura lesions, primarily on the legs3. There may also be signs of arthralgia, fatigue, and general malaise. In the literature, some cases showing convulsions, kidney failure, or pulmonary haemorrhage have also been reported. The most common alterations in laboratory tests are neutropenia, a p-ANCA pattern, and the presence of antiphospholipid antibodies. More specific immune markers include antielastase antibodies. However, to confirm the diagnosis, levamisole detection in urine by using gas chromatography-mass spectrometry is required. However, most of the reported cases, including ours, are unconfirmed. This is because of the unavailability of testing techniques4 and the short half-life of levamisole (5.5~6 h)5. Two histological patterns have been documented: leukocytoclastic vasculitis and thrombotic vasculopathy. In most patients, skin lesions resolve spontaneously 2~3 weeks after stopping levamisole. However, the serological alterations may persist for up to 14 months3.