Comparing the topical preparations of indigo naturalis from Chinese and Iranian origin in the treatment of plaque-type psoriasis: a preliminary randomized double-blind pilot studyThis study aimed to compare Iranian ointment made of Indigofera tinctoria with Chinese ointment made of indigo naturalis from China, and topical betamethasone on the severity of chronic plaque-type psoriasis based on Psoriasis Area and Severity Index (PASI) score.

Abstract Introduction : Psoriasis is an inflammatory and proliferative disease. Indigo naturalis is a blue herbal pigment extracted from Indigofera tinctoria and other plants. The purpose of this study was to compare Iranian ointment made of Indigofera tinctoria with Chinese ointment made of indigo naturalis from China, and topical betamethasone on the severity of chronic plaque-type psoriasis. Methods : In this preliminary randomized double-blind pilot study, patients with localized chronic plaque-type psoriasis divided into three groups to receive either topical Iranian herbal ointment, Chinese herbal ointment, or betamethasone ointment twice a day for 8 weeks. Results : At the end of the 8th week of treatment, the mean PASI score in the three groups was 5.8 ± 3.13, 6.32 ± 2.85, 3.04 ± 2.23 in Chinese, Iranian and betamethasone ointment respectively; and the mean PASI score changes from baseline was statistically significant only in the topical betamethasone group (p=0.0082). Conclusion : The Iranian herbal ointment used for psoriasis for 8 weeks caused lower clinical response in comparison with topical betamethasone or Chinese herbal ointment in the studied patients.