Epidemiological study of the prevalence of allergic reactions to Hymenoptera in a rural population in the Mediterranean area.

BACKGROUND

Systemic allergic reactions to Hymenoptera venom occur in a percentage that varies from 0.4 to 3.3%. Epidemiological studies indicate that from 15 to 25% of the general population can be sensitized to different Hymenoptera venom as well as the fact that the degree of exposure may be related to the prevalence found in those studies.

OBJECTIVE

The objective of this study was to evaluate the prevalence of insect sting allergy and the venom sensitization in a rural population to three Hymenoptera previously found in the area: Polistes dominulus (Pd), Vespula germanica (Vg) and honey bee (Hb).

METHODS

A rural community located in the south-east of Spain, close to the Mediterranean Sea, was selected since the stinging Hymenoptera having been previously identified. A random sample of 310 subjects from the village census was studied. A questionnaire and a serum sample were obtained from every patient. The evaluation was conducted by a family doctor, who focused on the reactions to Hymenoptera sting, age, sex, occupation, atopia, previous Hymenoptera sting, stinging insect, interval to last sting and average stings per year. RAST to Hymenoptera venoms were also determined.

RESULTS

The prevalence of systemic reactions was 2.3% (57.6% of them had a positive RAST). Large local reactions were found in 26.4% (only 28.5% of them had a positive RAST). Asymptomatic sensitization (positive RAST) was observed in 16.4% of subjects without reaction. Only a weak correlation between subjects with less than 3 years' interval to last sting exposure and positive RAST results was noted, whether they presented with a clinical reaction or not (P < 0.05).

CONCLUSIONS

The prevalence of systemic sting reactions in our rural community is higher than other general populations in the same Mediterranean area, and similar to other rural populations studied. The degree of exposure influences not only the prevalence found but also the detection of specific serum IgE.