New indications and new retinoids.

In addition to well-accepted indications, etretinate has a beneficial effect in a variety of other dermatoses such as the hyperkeratotic eczema of the palms and soles, prurigo nodularis, and other nonpsoriatic, sterile, pustular eruptions. Due to its influence on dermal inflammatory processes and immunomodulation of the tissue response, etretinate is effective in cutaneous lupus erythematosus, certain bullous disorders like pemphigus herpetiformis, the persistent variant of Grover's disease, dermatitis herpetiformis, and bullous pemphigoid. Isotretinoin is reported to be effective in cutaneous sarcoidosis, disseminated granuloma annulare, systemic sclerosis and tumors of the cutaneous appendages. New synthetic retinoids have been developed. Etretin, the main metabolite of etretinate, was shown to be effective and to have a short elimination half-life of approximately equal to 50 h. Arotinoid ethyl ester and arotinoid-free carboxylic acid are effective in minimal doses 500-fold lower than etretinate. Arotinoid ethyl ester was shown not to increase serum lipids. Arotinoid ethyl sulfone is the first retinoid without bone toxicity in animal experiments. Motretinide is the ethylamide of tretinoin and is reported to be effective in the local treatment of acne. Some of the new polyaromatic retinoids appear to have sebosuppressive, antikeratinizing and/or anti--inflammatory effects via topical application.