Skin inflammation induced by hypomagnesaemia in the rat.

Hairless rats fed a hypomagnesaemic diet developed an inflammatory dermatosis characterized by papular erythematous plaques. The dermatosis was long-lasting and could be observed for up to 6 months. It was inhibited by intraperitoneal injection of magnesium or dexamethasone but not by mepyramine, cimetidine, theophylline, aspirin or indomethacin. Analysis of semithin sections only showed oedema in the epidermis and superficial dermis with occasional intra-epidermal splitting. Direct immunofluorescence did not detect immunoreactant deposits within epidermis or dermis. Hypomagnesaemic dermatosis in hairless rats is proposed as a model for the pharmacological study of skin inflammation.