Burton’s Line from Chronic Lead Intoxication
A 39-year-old man presented to the emergency department with a 4-week history of increasing abdominal pain and constipation. Physical examination of the abdomen and the results on abdominal imaging, including ultrasonography and computed tomography, were normal. Laboratory investigations revealed a hemoglobin level of 12.5 g per deciliter (normal range, 14.0 to 17.5). Findings on upper endoscopy and colonoscopy were normal. Since the cause of the gastrointestinal symptoms was unclear, laboratory investigations for porphyria were performed. A 24-hour urine test showed an excretion level of delta aminolevulinic acid of 545 μmol per day (normal range, <49), and the lead level in blood was markedly elevated at 136 μg per deciliter (6.55 μmol per liter). Physical examination was repeated, and a gray line along the margins of the lower gums, known as Burton’s line, was noted (arrow). Burton’s line is a sign of chronic lead intoxication that develops when lead reacts with oral bacteria metabolites. The patient then confirmed a 10-year history of chewing opium. Analysis of a sample of the patient’s opium revealed a lead concentration of 17 mg per 1 g of opium. Lead may sometimes be added to opium to increase its weight when it is sold. The patient was treated with chelating agents and was counseled about the importance of oral hygiene; he also stopped chewing opium. At follow-up 7 months after the initiation of treatment, the patient’s abdominal pain and constipation had resolved, and Burton’s line was markedly diminished. Friederike Helmich, M.D. Guntram Lock, M.D. Albertinen-Krankenhaus, Hamburg, Germany source: nejm.org
