SKIN SIGNS IN THE DIAGNOSIS OF THALLIUM POISONING

A 45-year-old man developed a painful and rapidly progressive sensory- motor polyneuropathy associated with confusion and convulsions. This r esulted in hypoventilation and led to respiratory failure and coma. A rapid and diffuse alopecia occurred after 3 weeks in the intensive car e unit. Examination of hair roots under polarized light detected dystr ophic anagen hairs with dark bands caused by empty spaces in the disor ganized cortex. These dark zones were originally reported in patients with thallium poisoning and a toxicological investigation confirmed th allium exposure. The classical systemic symptoms and the various derma tological signs are reviewed, and the origins of contamination and phy siopathology discussed.