Efficacy of 15% Azelaic Acid in Psoriasis Vulgaris: A Randomized, Controlled Clinical Trial

Background: Psoriasis is a common disorder affecting 1-3 percent of the general global population. Many therapeutic modalities have been suggested for treatment of this condition, but still there is no definite treatment for this disease. The objective in this study was to evaluate the efficacy of topical azelaic acid gel versus placebo in the treatment of psoriasis vulgaris. Patients, Materials and Methods: This study was a single-blinded randomized clinical trial. Overall, 31 patients were selected and the left or right sided lesions of the patients were randomized to receive either 15% azelaic acid or gel twice daily for a one-month period. Two symmetrical lesions with almost similar severity in every patient were selected and considered as index lesions to evaluate lesion response to treatment. The severity of erythema, scaling, hyperkeratosis and pruritus of the index lesions were scored in range of 0-3 for each lesion by the investigator at the baseline and follow up visits. The percent of involvement of each side of body was also measured using rule of nines. The collected data were analyzed using statistical tests including Mann-Whitney and ANOVA tests. Results: There was no significant difference between the two groups before treatment (P>0.05). After treatment, however, except pruritus, there was significant difference between the two groups (P<0.05). There was no significant difference regarding total psoriasis score between the two groups before treatment (P>0.05). After treatment, however, there was significant difference between the two groups (P<0.05) in favor of more efficacy for azelaic acid. There was no significant difference regarding percent of body involvement between the two groups before treatment (P>0.05). After treatment, however, there was a significant difference between the two groups (P<0.05) in favor of more efficacy on the part of azelaic acid gel. Discussion: The results of our study showed that 15% azelaic acid gel was effective in reduction of purities, scaling and hyperkeratosis of psoriasis plaques. This treatment was also effective in reduction of skin involvement with psoriasis. It is recommended that a longer study be performed that can better evaluate the efficacy of this treatment against plaque-type psoriasis.