New aspects and developments in antipsoriasis retinoid therapy

: Oral retinoids have been largely introduced in the management of psoriasis. The beneficial effect, however, differs according to the clinical type and requires an appropriate dosimetry: Pustular types respond rapidly and sufficiently to high initial doses (75 mg/d). In psoriatic erythroderma low initial doses (35 mg/d) seem indicated increasing the dose to 50 mg/d after 2-4 weeks. In chronic stationary psoriasis medium doses (50 mg/d) should be given as adjuvant treatment, combined with anthralin or UVB (SUP). In severe cases oral retinoids can be administered with systemic PUVA (RePUVA). Cheilitis, mucosal dryness and hair loss may appear temporarily as dose dependent side-effects. No hepatotoxicity was found. Interactions with serum triglycerides were seen, particularly in patients with diabetes, obesity, alcoholism and elevated triglyceride levels before treatment. Beside the compound Ro 10-9359 new synthetic derivatives are under investigation, either for topical therapy (Ro 11-1430), or for systemic therapy in lower doses (Ro 12-7554). Their mechanisms of action are still unknown. New findings suggest that retinoids may exert an immunomodulatory effect on dermal cells, in addition to their influence on keratinocytes.