Efficacy of topical 5% liquor carbonis detergens vs. its emollient base in the treatment of psoriasis

Tar has been a mainstay in the treatment of psoriasis for centuries, but despite its widespread use, there is little evidence supporting its clinical efficacy without the combined use of ultraviolet radiation. The purpose of this study was to compare psoriasis improvement rates in patients using 5% liquor carbonis detergens (LCD) in an emollient base with the emollient base alone. Eighteen patients completed a randomized, bilaterally controlled, double-blind study. Emollient-treated plaques showed a mean improvement of 35.3% by 4 weeks of treatment, and LCD therapy produced a mean improvement of 48.7%, a difference which was statistically significant.