LITHIUM-INDUCED FOLLICULAR HYPERKERATOSIS

A wide range of cutaneous reactions have been described in association with lithium therapy. Follicular eruptions have been noted briefly, b ut are not well documented in the dermatological literature. We report a 68-year-old man who developed a florid erythematous follicular erup tion on the extensor surfaces of the limbs, with macular truncal eryth ema 6 months after commencing lithium therapy. His blood lithium level s were within the therapeutic range and there was no clinical evidence of lithium toxicity. Histology of lesional skin showed perifollicular inflammation and follicular plugging. The eruption improved on drug w ithdrawal. The cutaneous reactions to lithium and possible pathogenic mechanisms are discussed.