[Beneficial effect of oral retinoid in psoriatic hyperproliferation. Autoradiographic studies on involved and non involved skin (author's transl)].

In 16 patients with generalized psoriasis treated with oral retinoid (Ro 10-9359; 1 mg/kg body weight/(day) autoradiographic studies were performed before, and 24 h, 48 h, 1 week and 3 weeks after beginning of treatment on involved and non involved epidermis. During the first week no significant changes of all cellular parameters were found. However, after 3 weeks of continuing medication the increased 3H-thymidine labelling index was markedly lowered and the prolonged DNA synthesis time was shortened; whereas, the cell cycle time remained unaffected. The findings revealed that oral retinoid has a distinct influence on epidermal cell proliferation towards normalization in both involved and non involved epidermis in psoriasis. The time needed for this effect indicates that the drug does not directly interfere with the cell cycle. It seems reasonable, therefore, to combine oral retinoids as a basic adjuvant drug with other antipsoriatic techniques, such as retinoid + anthralin, retinoid + PUVA, retinoid + UVB.