Plumbism

A 54-year-old man was admitted with anaemia and myalgia of both thighs. He had been working in a chemical plant where he was chronically exposed to lead stearate in the process of manufacturing polyvinyl chloride. He admitted that he did not wear a gas mask all the time at the workplace, in violation of the rules. Physical examination revealed a blue–black line (lead line) at the gum margin (top). The red cell count was 3·29 × 1012/l, the haemoglobin level was 9·8 g/dl, and the haematocrit was 0·31. The reticulocyte count was 5·4%, and the MCV was 91 fl. Basophilic stippling was seen in 1·8% of erythrocytes in the peripheral blood smear stained with Wright's stain (bottom). A bone marrow aspirate showed erythroid hyperplasia with 5% ringed sideroblasts and basophilic stippling-positive normoblasts. Urinary δ-aminolaevulinic acid and coproporphyrin as well as free erythrocyte protoporphyrin were increased. The blood level of lead was 138·8 µg/dl of whole blood (normal value 10–40 µg/dl). After the diagnosis of plumbism, the patient was treated with a combination of dimercaprol and edetate disodium calcium. This was followed by a gradual decrease in blood lead levels and improvement of the anaemia.