[Drug eruptions caused by lithium salts].

The systemic complications of therapy with lithium are well known, but toxidermia has only been recognised since 1968. The carbonate (Teralithe) is the lithium salt which is mainly responsible, leading to minor dermatoses: oedema, pruritus, alopecia, urticaria, purpura, allergic vasculitis, pretibial ulceration. Some more specific conditions have been individualised by their severity and rarity: acne form eruptions, seborrheic dermatitis, follicular keratoses and psoriasis-like dermatosis as well as true psoriasis induced or aggravated by lithium. The authors review the literature and discuss the pathogenesis of these toxidermias. The cause of some dermatoses can be explained, especially the allergic vasculitis and psoriasis lesions. The underlying mechanism of most of these conditions remains unknown, but excessive tissue concentrations of the drug probably play an important role in inducing these complications.