Clinical observations of mosquito bite reactions in man: a survey of the relationship between age and bite reaction.

To evaluate the mechanism of mosquito bite reaction in man, the reaction to Aedes albopictus was observed in 162 subjects ranging in age between 1 to 68 years old. Bite reactions were found to consist of both an immediate and a delayed reaction. The eruption and time course of the immediate reaction were consistent with type I hypersensitivity. The eruption and time course of the delayed reaction were consistent with cutaneous basophil hypersensitivity. Positive rates of immediate reaction increased from early childhood to adolescence and decreased with age from adulthood. The appearance and intensity of the delayed reaction decreased with age. Mosquito bite reactions in human beings exposed continuously and regularly are known to change from stage 1 to stage 5 (stage 1; no reaction, 2; delayed reaction only, 3; immediate and delayed reaction, 4; immediate reaction only, 5; no reaction). Analysis of the relationship between age and bite reaction in this study indicated that the principle held true even when the exposures were irregular or at random.