The effect of Melissa officinalis syrup on patients with mild to moderate psoriasis: a randomized, double-blind placebo-controlled clinical trial

Psoriasis is an immune-mediated inflammatory skin disease. It can involve any body skin area, particularly the scalp, lower back, elbows, and knees. There are several topical and systemic therapies for the treatment. Nowadays, herbal medicines are popular treatments for dermatologic conditions. This two-arm parallel, randomized placebo-controlled clinical trial was conducted to examine the hypothesis of the efficacy of Melissa officinalis syrup on patients with mild-to-moderate Plaque psoriasis. Among 100 patients, 95 participants completed the trial and five of them withdrew. The mean pruritus intensity and PASI scores decreased significantly in the intervention group compared to the placebo group (P < 0.001). The DLQI score in the intervention group increased post-treatment compared to pre-treatment (P = 0.029); however, there was no significant difference between the intervention and control group at the end of the study (0.065).