Background: 9-cis-Retinoic acid (9-cis-RA) has a particular pattern of binding and activating retinoid receptors. Treatment of chronic hand eczema is often refractory to conventional treatment. Objective: Evaluation of oral 9-cis-RA therapy in chronic hand eczema in a pilot study. Methods: Thirty-eight patients with refractory chronic hand eczema were treated in an exploratory open-label study with oral 9-cis-RA. Results: Twenty-one (55%) showed a very good response, 13 (34%) a good response, 2 (5.5%) a moderate response and 2 (5.5%) no response. Side effects were mild. Conclusion: 9-cis-RA is a valuable drug when given at low doses to patients with chronic hand eczema.

Topically applied retinoic acid induces partial or complete clinical regressions of senile or actinic keratoses as wall as of basal cell carcinomas of the skin. 15 out of 16 treated basal cell carcinomas regressed by more than 50 %, regressions being complete in 5 cases. The mode of action of retinoie acid on premalignant and malignant lesions is discussed.

Background: 9-cis-Retinoic acid (9-cis-RA) is as active as 13-cis-retinoic acid (13-cis-RA) in inhibiting the proliferation of cultured human sebocytes and in reducing the size of sebaceous glands of hamsters. Objective: Evaluate the anti-acne effect of 9-cis-RA compared to that of 13-cis-RA in a pilot study. Methods: Four young male patients with acne were treated in an open study consecutively with 9-cis-RA and 13-cis-RA given at similar doses. Results: No beneficial effects were observed with 9-cis-RA in any of the patients whereas all responded favorably to 13-cis-RA. Conclusion: For the two retinoids tested, the anti-acne effect correlates with the sebosuppressive effect in humans.

Background: Retinoids were shown to be effective in the treatment of both oral and cutaneous forms of lichen planus. Objective: Confirm the beneficial effect of low doses of oral tretinoin in lichen planus. Methods: Eighteen patients with lichen planus were treated in an open study for up to 19 months. Efficacy and safety data were recorded. Results: Complete remission was observed in 13 (72%) and marked improvement in 4 (22%) out of 18 patients. Six patients showed moderate and 12 had no side effects. Conclusion: Tretinoin is a valuable drug when given at low doses to patients with lichen planus who failed to respond to other therapies.