Skin test resensitization after allergological study in patients with immediate allergic reactions to betalactams

RATIONALE: Mosquito bite-induced systemic reactions are an increasing clinical concern and have not been well studied.METHODS: Sera were collected from 14 individuals with systemic reactions to mosquito bites (10 from the US and 4 from Canada, Switzerland, Germany and Japan).Systemic reactions were defined as having at least one of the following symptoms following a mosquito bite: hypotension or decrease/loss of consciousness, urticaria, angioedema or edema, and wheezing or dyspnea.An indirect ELISA was developed to measure mosquito saliva-specific lgE and IgG antibodies to 5 common mosquito species with different world distributions: Aedes aegypti, Aedes vexans, Aedes albopictus, Anopheles sinensis and Culex quinquefasciatus.Thirty one Manitobans with negative mosquito bite tests served as controls. RESULTS:The mean levels of saliva-specific IgE to all 5 species were significantly higher in the reactive individuals than the controls (p<0.061for Aedes vexans and p's<0.008for the remaining 4 species).Interestingly, unlike severe local reactions to mosquito bites, the mean levels of saliva-specific IgG were not statistically higher in the reactive individuals than controls (p's>0.05).Using the mean of the controls plus 1SD as a cutoff level, 3 individuals were positive to only one species: Culex quinquefasciatus (from the US), Aedes aegypti (the US), and Aedes vexans (Japan).The remaining 11 individuals were all positive to Aedes albopictus plus additional up to 4 other species.CONCLUSIONS: Systemic reactions are caused by mosquito saliva-specific IgE only.Species-shared and species-specific IgE responses exist.Aedes albopictus has the most common species-shared allergens.