Is topical nitric oxide and cryotherapy more effective than cryotherapy in the treatment of old world cutaneous leishmaniasis?

BACKGROUND Current systemic treatments for cutaneous leishmaniasis are limited by their toxicity, high cost, side effects and the emergence of drug resistance. New approaches, including topical therapies, are urgently needed. Nitric oxide (NO) produced by human and canine macrophages has long been demonstrated to be involved in the intracellular killing of Leishmania. OBJECTIVE This study was designed to determine the clinical responses (healing, or non-healing) and effectiveness of NO plus cryotherapy for the treatment of old world cutaneous leishmaniasis (CL). METHODS A double-blind, randomized, placebo-controlled clinical trial was performed for the evaluation of therapy with topical nitric oxide 3% and cryotherapy in 63 Iranian patients with CL in the south of Iran. RESULTS Thirty of 36 participants (83.3%) had complete improvement in the treatment group as did 20 of 27 (74.1%) from the control group (p = 0.627). Erythema, a burning sensation and irritation occurred in seven participants from the treatment group and one patient from the placebo group (p = 0.063). CONCLUSION This study could not show any more effectiveness from combining a 12-week course of treatment with 3% nitric oxide cream and a once-weekly treatment with cryotherapy in comparison with cryotherapy and placebo in patients with CL.