Etretinate therapy for psoriasis: clinical responses, remission times, epidermal DNA and polyamine responses

A prospective study was carried out over 12 months involving twenty patients with psoriasis vulgaris who were treated with all-trans-aromatic derivative of vitamin A, etretinate. Etretinate was found to be an effective therapy for this skin disorder. Arthritis accompanying psoriasis vulgaris in four of seven of our patients was greatly improved by retinoid therapy. Side effects were found to be dose-related and included mucocutaneous abnormalities as well as abnormalities of blood lipids and liver function tests. Maintenance therapy appears to be required in nearly all patients, with relapse occurring within approximately 8 weeks. Polyamine biosynthesis has been determined previously to be accelerated in patients with psoriasis vulgaris. Polyamines (putrescine [Pu], spermidine [Sp], and spermine [Sm] were measured in skin samples of six patients with stable plaque-stage psoriasis before treatment and at 4 weeks during treatment. Pu, Sp, Sm levels, as well as the Sp/Sm ratio, fell. Epidermal DNA synthesis is increased in involved and noninvolved psoriatic skin; it was measured before and during treatment (at 4 weeks) in this study and found not to fall significantly during this period of time. Polyamine levels therefore decreased prior to any significant expected decrease in epidermal DNA synthesis measured in both involved and uninvolved skin.