Épidémiologie des allergies alimentaires

Abstract

The epidemiology of food allergies is less well known than that of other allergic conditions such as atopy, asthma, allergic rhinitis and eczema, all of which have been the subject of large multicentric international studies. Epidemiological studies of food allergies are difficult to carry out because the diagnosis is complex and the methodology of such studies is complicated. A recent review of the literature shows that the prevalence of food allergies is reported to be from 2% to 4%, all ages included; it seems to have doubled over the last 10–15 years. In the only epidemiological study of food allergy that we found, the yearly risk of death due to any food allergy was estimated to be 1 in 800,000. The estimated prevalence of the principal food allergies in infants between 2 and 2 1/2 years of age is reported to be as follows: hen’s egg = 1.6–2.6%; cow’s milk = 1.1–2.2%; peanut = 0.9–1.2%; other nuts = 0.5%. A group of investigators who studied a cohort of subjects living on the Isle of Wight once and then again, using the same methodology, 5 years later found that the prevalence of peanut allergy had doubled over that period, going from 0.5% to 1%. They also found that sensitisation to this food had tripled, going from 1.1% to 3.3%. We believe that new multicentric, prospective studies are necessary to verify these reported results; they should take into account the subjects’ eating habits, since they are often very different in different countries. We recommend that the apparent increase in the frequency of severe cases of food allergy, i.e., systemic reactions and anaphylactic shock, calls for close surveillance, with notification of such incidents to an Allergo-Vigilance network.