D-chiro-inositol as a treatment in plaque psoriasis: A randomized placebo-controlled clinical trial.

Cyclitols are widely available natural sugars which do not exert toxic effects. Their anti-inflammatory and antioxidant properties may be used in the treatment of psoriasis. The aim of this placebo-controlled, double-blind study was to evaluate the clinical effects of D-chiro-inositol (DCI) in mild plaque psoriasis (46 psoriatic patients and 10 healthy volunteers). Three stable psoriatic plaques were selected for evaluation in every patient. Different samples were applied on each lesion twice a day: vehiculum without an active agent, containing 1% DCI and 0.25% DCI. The lesions were assessed using the PSI, VAS scale, and the objective measurement of hydration, transepidermal water loss (TEWL), elasticity, and thickness (DermaLab Combo) at 0, 3, and 6 weeks. PSI and VAS were improved in all groups without significant statistical differences. 1% DCI sample presented the highest statistically significant increase in the hydration of 50%, but it was still significantly lower than in healthy controls. TEWL increased for 1% DCI, which was a statistically significant difference compared to 0.25% DCI and still higher than in controls. An improvement in elasticity was observed in all lesions-it was statistically significant for 1% DCI. The thickness of the lesion decreased for 1% DCI, but the change was not statistically significant. Subepidermal low-echogenic band showed a decreasing tendency in all groups, but it was not statistically significant. Favorable 1% DCI sample results indicate that it may be used as an adjuvant to the local treatment of psoriasis.