A comparative study of 20% azelaic acid cream versus 5% tranexamic acid solution for the treatment of postinflammatory hyperpigmentation in patients with acne vulgaris: A single-blinded randomized clinical trial

There is a lack of evidence on the therapeutic efficacy of topical tranexamic acid (TA) for the treatment of acne-related postinflammatory hyperpigmentation (PIH). The current study aimed to assess the efficacy of twice-daily administration of 20% azelaic acid (AZA) cream versus 5% TA solution for the treatment of PIH in patients with acne vulgaris.Patients in the present single-blinded randomized clinical trial were randomized into AZA or TA groups for 12 weeks. The rate of healing was assessed by scoring recorded photographs based on postacne hyperpigmentation index (PAHI) at baseline, 4th, 8th, and 12th weeks. The frequency of side effects was examined and recorded at each study time point.Thirty volunteers in each treatment group completed the intervention. PAHI score in both AZA and TA groups improved during the study course (Ptime < 0.001, for both groups). However, mean PAHI scores were comparable in the two groups (Pgroup = 0.05). No significant interaction was also found between time and treatments in terms of PAHI score (Ptime × group = 0.66). The frequency of treatment-related side effects was significantly higher in the AZA group compared to the TA group at week 4 of treatment (P < 0.05). However, no significant difference was observed in the frequency of reported side effects at weeks 8 and 12 of the treatment (P > 0.05).Topical administration of 20% AZA cream and 5% TA solution was comparably efficient in the treatment of acne-related PIH with a significantly better safety profile of TA in the 1st month of the treatment.