Active substance for treating alterations of the skin and the mucous membranes

The invention relates to an active substance for the topical treatment of skin and mucous membrane changes, in particular those caused by metabolic and tissue diseases. The active substance is a substance mixture of two components a) and b), whereina) from at least one aminopolycarboxylic acid, and / or their salts and / or their derivatives, or from gluconic acid, and / or their salts and / or derivatives, andb) consists of at least one salt and / or derivative of a fruit acid. The active substance leads to the rapid resolution of the symptoms among other things in psoriasis, acne, lichen planus, neurodermatitis, periodontitis, gingivitis, herpes. It can be used pharmaceutically and cosmetically.