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.

Vitamin A, Vitamin A acid (retinoic acid) and their synthetic derivatives were variously applied in the management of psoriasis with different therapeutic results. Obviously, they influence the proliferation rate and the differentiation of human keratinizing epithelia and have beneficial effects on skin diseases with disturbances of keratinization, including psoriasis. Systemic application of Vitamin A has been yet largely abandonned since high dosages leading to clearing develop evident systemic toxicity. The anti-psoriatic effect of Vitamin A acid is either moderate or restricted, because of side effects. Only its combined local application with topical corticosteroids may be considered. Oral application of newly synthesized retinoids, however, was beneficial in psoriasis, particularly in erythrodermic or pustular types. With this group of retinoids new pathways were opened in dermatotherapy which may help to replace cytostatic drugs in these cases. Additionally, oral retinoid treatment may be introduced as an adjuvans in the management of widespread psoriasis, in order to enhance the effect of anthralin, PUVA or UVB treatments.

Bei 16 Psoriatikern mit generalisierter Psoriasis, die unter oralet Retinoid-Therapie standen (1 mg/kg Körpergewicht täglich), wurden 24h, 48h, 1 Woche und 3 Wochen nach Therapiebeginn autoradiographische Untersuchungen an der befallenen und nicht befallenen Epidermis durchgeführt. Während der ersten Behandlungswoche fanden sich keine signifikanten Veränderungen der zellkinetischen Parameter, doch nach 3wöchiger Therapie kam es zu einer Minderung des gesteigerten 3H-Markierungsindex und zu einer Verkürzung der verlängerten DNS-Synthesezeit; die mittlere Generationszeit blieb weiterhin unbeeinflußt.