Burton's line explained

Differential:	Chronic lead poisoning

Burton's line, also known as the Burton line or Burtonian line, is a clinical sign found in patients with chronic lead poisoning. It is a very thin, black-blue line visible along the margin of the gums, at the base of the teeth.^{[1] [2]} It is caused by the reaction between circulating lead and sulphur ions produced by oral bacteria, forming deposits of lead sulfide in the gums.^[3]

The sign was described in 1840 by Henry Burton:^[4]

A similar line, the "bismuth line", occurs in people who have ingested bismuth compounds; bismuth, however, is of very low toxicity.

Notes and References

1. Pearce JM . Burton's line in lead poisoning . Eur. Neurol. . 57 . 2 . 118–9 . 2007 . 17179719 . 10.1159/000098100 . 2009-03-21. free .
2. Helmich. Friederike. Lock. Guntram. 2018-11-08. Burton's Line from Chronic Lead Intoxication. New England Journal of Medicine. 379. 19. e35. 10.1056/NEJMicm1801693. 0028-4793. 30403939. 205088502 .
3. Rao JV, Vengamma B, Naveen T, Naveen V . Lead encephalopathy in adults . J Neurosci Rural Pract . 5 . 2 . 161–3 . April 2014 . 24966557 . 4064184 . 10.4103/0976-3147.131665 . free .
4. On a remarkable effect on the human gums, produced by the absorption of lead . Medico-Chirurgical Transactions . Burton . Henry . 1840-01-14 . 23 . 63–79 . 10.1177/095952874002300106 . 2116895 . 20895719.