Rupatadine 10 mg in the treatment of immediate mosquito-bite allergy.

Background: People frequently experience wealing and delayed papules from mosquito bites. Wealing is mediated by antisaliva IgE antibodies and histamine. Rupatadine is a new antihistamine effective in allergic rhinitis and urticaria, but the effect on mosquito-bite allergy is not known.

Objective: To determine the effectiveness of rupatadine in inmediate mosquito-bite allergy-confirmed adult patients.

Methods: A double-blind, placebo-controlled, cross-over study was performed with rupatadine 10 mg and matched placebo in 30 mosquito-bite-sensitive adults. The mean age was 37 years and the subjects had suffered from harmful mosquito bites for a mean of 15 years. Either rupatadine or placebo was taken at 08:00 am for 4 days, followed by a 5 day wash out period and then alternative treatment was given for 4 days. On day 3, in both drug periods the subjects received two Aedes aegypti mosquito-bites on the forearm. The size of lesions and intensity of pruritus [visual analogue scale (VAS)] were measured after 15 min bite reaction.

Results: Twenty-six subjects were analysed for efficacy. The size of the 15 min bite reaction under placebo was of 106 mm2 and under rupatadine, of 55 mm2. This is a significant decrease (48%; P=0.0003). The accompanying pruritus decreased from 60 (VAS; median) under placebo to 47.5 under rupatadine, which also is a significant (P=0.019) difference. There was no significant (P=0.263) difference in adverse events under rupatadine and placebo.

Conclusion: The present placebo-controlled study in mosquito-bite-sensitive adults shows that rupatadine 10 mg prophylactically given is an effective treatment for the mosquito-bite wealing and skin pruritus.