THE EFFICACY OF PRRRIKWEG(TM) GEL IN THE TREATMENT OF INSECT BITES - A DOUBLE-BLIND, PLACEBO-CONTROLLED CLINICAL-TRIAL

Objective: This study was conducted to examine the efficacy of Prrrikw eg(R) gel, a homeopathic after-bite gel, in relieving the effects of m osquito bites, in particular itching and erythema. Design: A double-bl ind, randomized, placebo-controlled clinical trial. Setting: London Sc hool of Hygiene and Tropical Medicine. Subjects: 100 healthy volunteer s. Methods: All subjects were bitten under laboratory conditions by Ae des aegypti mosquitoes at one spot on the ventral aspect of the left f orearm and another on a corresponding position on the right forearm. O ne spot was treated with the homeopathic after-bite gel and the other with a placebo gel. Main outcome measures: Itching was assessed on a 5 -point discrete rating scale at 0, 0.5, 1, 26.5, and 48 h post-bite to compare the itch-relieving efficacy of the two treatments. Erythema d evelopment was assessed by photographing the bite sizes, measuring len gth and width of the erythema with a calliper, and comparing the ratio of the erythema surface at baseline (T-0) to the mean erythema surfac e at 0.5, 1, 26.5, and 48 h post-bite (T-mean) for the two treatments. Results: Testing erythema development by comparing the ratio T-0/T-me an,T- after-bite gel and the ratio T-0/T-mean,T- placebo gel gave a tw o-tailed p = 0.098 (95% Cl, -0.031-0.361) in favour of the after-bite gel. There was not a statistically significant difference between the itch relief provided by the two treatments (two-tailed p = 0.424; 95% Cl, -0.541-0.191). The correlation between itching and erythema was si gnificant (r = 0.46; p < 0.001). Conclusions: There are strong indicat ions that the homeopathic after-bite gel reduces erythema development following mosquito bites. The homeopathic mother tinctures of Echinace a angustifolia DC., Ledum palustre L., Urtica urens L. as well as the Hamamelis extract in this gel, whether alone or in combination, are th e biologically active ingredients. The homeopathic after-bite gel was not demonstrated to relieve itching; however, based on the correlation between erythema and itching, an effect on itching is not inconceivab le.