Improvement of sulphur mustard-induced chronic pruritus, quality of life and antioxidant status by curcumin: results of a randomised, double-blind, placebo-controlled trial

Abstract

Skin is among the first and most heavily damaged organs upon sulphur mustard (SM) exposure. Pruritus is the most common chronic skin complication of SM, which adversely affects the quality of life (QoL). However, current therapies for the management of SM-induced pruritus are very limited and associated with side effects. The present trial investigated the efficacy of curcumin in the alleviation of SM-induced chronic pruritic symptoms. A total of ninety-six male Iranian veterans (age 37-59 years) were randomised to receive either curcumin (1 g/d, n 46) or placebo (n 50) for 4 weeks. Serum concentrations of substance P and activities of antioxidant enzymes were measured at baseline and at the end of the trial. Assessment of pruritus severity was performed using the pruritus score, visual analogue scale (VAS) and scoring atopic dermatitis (SCORAD) index. QoL was evaluated using the Dermatology Life Quality Index (DLQI) questionnaire. Serum concentrations of substance P (P<0·001) as well as activities of superoxide dismutase (P=0·02), glutathione peroxidase (P=0·006) and catalase (P<0·001) were significantly reduced in the curcumin group, while no significant change was observed in the placebo group. Curcumin supplementation was also associated with significant reductions in measures of pruritus severity including the pruritus score (P<0·001), VAS score (P<0·001), overall (P<0·001) and objective SCORAD (P=0·009), and DLQI's first question (P<0·001). None of these measures was significantly changed in the placebo group. As for the QoL, although DLQI scores decreased in both groups (P<0·001 and P=0·003 in the curcumin and placebo groups, respectively), the magnitude of reduction was significantly greater in the curcumin group (P<0·001). In conclusion, curcumin may be regarded as a natural, safe, widely available and inexpensive treatment for the management of SM-induced chronic pruritus.