Cutaneous nodular reaction to oral mercury

Abstract

A 24-year-old man had erythematous, subcutaneous nodules on the right forearm and left knee of 1 week's duration (Fig. 1). Previously, he had had arthralgias, loss of consciousness, headaches, abdominal pain, hand tremor, and fight hemiparesis of 4 years' duration. Examination revealed a 1.5 x 2 cm nodule on the lateral aspect of the right forearm and two nodules, measuring 1 x 2 cm and 2 x 3 cm, above and below the left knee. The nodule on the fight forearm was elevated, erythematous, and tender. The other nodules were ill defined and mildly erythematous and had a scaly surface. The excised nodule from the right forearm contained tiny multiple foci of a liquid metallic material. The patient's history revealed that he had frequently eaten duck soup containing metallic mercury for treatment of a neck abscess 18 years earlier. His elder brother had also eaten the same soup several times, but no symptoms developed except intermittent arthralgias. Mercury levels in a 24-hour urine collection (0.758 ~tg/ml [normal, < 0.02 gg/ml]) and blood (1.606 gg/ml [normal, < 0.2 gg/ml]) were markedly increased, but other laboratory findings including complete blood cell count, urinalysis, stool examination, liver function test, renal function test, VDRL, hepatitis B virus markers, electrocardiography, electromyography, C-reactive protein, liver and kidney ultrasonography, computed tomographic scan and magnetic resonance image of brain were all normal or negative. Radiographs of the lesions showed multiple radiopaque stippled shadows (Fig. 2). A biopsy specimen from the nodule of the fight forearm showed dark-gray to black-opaque glob-