Comparative efficacy between 5% liquor carbonis detergens cream, 1% hydrocortisone cream and cream base in the treatment of chronic plaque psoriasis: a randomized, single-blind comparison study

Abstract

Background: Topical therapy is the first line treatment for patients with chronic stable plaque psoriasis affecting a limited body surface area. Topical coal tar is well known and has been effective treatment for psoriasis patients for a long time. However, there are only few clinical trials supporting its clinical efficacy comparing with topical corticosteroid and emollient.

Objective: To evaluate the efficacy and side effects of topical 5% Liquor Carbonis Detergens (LCD) cream comparing with topical 1% hydrocortisone cream and cream base in the treatment of chronic stable plaque psoriasis.

Materials and methods: A randomized, single-blind comparison study consisting of 8-week treatment phase and 4-week post-treatment follow-up phase. Patients with chronic stable plaque psoriasis were randomly recruited at the outpatient department of Institute of Dermatology, Bangkok, Thailand. Each patient was selected three similar psoriatic lesions on the trunk or extremities. The selected lesions were randomized to apply 5% LCD cream or 1% hydrocortisone cream or cream base twice daily. The three selected psoriatic lesions were evaluated using the severity (0-3) scale of erythema, scaling and induration (ESI score) in each visit. Evaluation was carried out at the end of 4^th and 8^th week during the treatment period and at the end of 12^th week during post-treatment follow-up period. Serial photography was taken in every visit. Self-evaluated adverse events by the patients were also recorded during the study period.

Results: Thirty-three of 38 recruited patients completed the study. At the end of 8-week treatment, the mean percentage reduction of the ESI score from baseline was 53.97% in 5% LCD treatment group, 31.98% in 1% hydrocortisone treatment group and 16.88% in cream base treatment group. The mean percentage of the ESI score reduction was statistically significant in all groups (p < 0.001) but 5% LCD treatment group was significantly superior to the others (p < 0.001). The mean percentage reduction in size of lesions from baseline to up until the end of the 8 weeks was 13.07% in 5% LCD treatment group which was not statistically significant (p = 0.306). While the mean percentage extension in size of lesions from baseline to up until the end of the 8 weeks was 37.75% in 1% hydrocortisone treatment group and 73.57% in cream base treatment group which were statistically significant (p = 0.006, p = 0.004 respectively). The adverse effect was mild local irritation without any systemic side effect in all three groups. The 5% LCD cream was safe and well-tolerated with some complaint about malodor, cloth staining (12.12%) and hyperpigmentation (9.09%).

Conclusion: Our study demonstrated that the 5% LCD cream achieved significantly greater improvement in the ESI score in comparison with 1% hydrocortisone cream and cream base. The 5% LCD cream is a safe and effective corticosteroid-sparing treatment for plaque-type psoriasis patients.