A PLACEBO-CONTROLLED CLINICAL-TRIAL INVESTIGATION THE EFFICACY OF A HOMEOPATHIC AFTER-BITE GEL IN REDUCING MOSQUITO BITE INDUCED ERYTHEMA

A randomised, placebo controlled clinical trial was conducted to exami ne the efficacy of a homeopathic after-bite gel in the symptomatic rel ief of mosquito bites. Sixty eight healthy volunteers were bitten unde r laboratory conditions by Aedes aegypti mosquitoes at three spots, on the ventral aspect of the forearm. One bite was treated with the home opathic after-bite gel, another bite with a placebo gel which was iden tical in appearance and smell to the homeopathic after-bite gel, and t he third bite remained untreated. Immediately after the bites and 1,3, 6,26 and 31 hours post-bite, the length and width of the erythema were measured with a calliper, and photographs were taken of the. bite sit es from which the size of the erythema was subsequently determined. Th is was followed by assessment of the extent of itching with a verbal a nalogue scale, and finally treatment took place. For each spot the tot al erythema was calculated as the area under the plotted curve of the erythema at different time points (mm(2)h) and the total sum of the i tch scores was determined. For the bites treated with the homeopathic after-bite gel the median total erythema was 10.500 mm(2)h. For the s pots treated with the placebo gel and the untreated spots the median t otal erythema was 12.900 mm(2)h and 13.300 mm(2)*h, respectively. The difference between the spots treated with the homeopathic after-bite gel and the untreated spots came close to significance (two-tailed P = 0.06), which was not the case for the difference between the spots tr eated with the homeopathic after-bite gel and the spots treated with p lacebo gel (P = 0.13). After pooling the data of a very similar previo us pilot study and the present study (n(total) = 83), the homeopathic after-bite gel was significantly superior to no treatment (two-tailed P = 0.003) as well as to placebo gel (two-tailed P = 0.03). Comparing itching after the three treatments, no significant differences could b e demonstrated. The extent of itching was positively correlated with t he area of the erythema (r = 0.63). Treatment of mosquito bites with t he homeopathic after-bite gel will reduce the erythema compared to no treatment. Comparison with the placebo gel suggests it is the plant ex tracts which are the active components of this gel.