Causes of food-induced anaphylaxis in Italian adults: a multi-centre study.

BACKGROUND: Data about food-induced anaphylaxis in Italy are missing. Objective: It was the aim of this study to detect the main foods/food allergens causing anaphylaxis in Italy.

METHODS: The frequency of anaphylaxis and the relative importance of many offending foods were assessed in 1,110 adult patients with food allergy diagnosed by common criteria at 19 allergy centres scattered throughout Italy from 1 January to 31 December 2007.

RESULTS: Fifty-eight of 1,110 (5%) food-allergic patients experienced at least 1 episode of anaphylaxis. On average, they were older than other food-allergic patients (34 vs. 31 years; p < 0.05). The majority of anaphylactic episodes occurred in patients sensitized to lipid transfer protein (LTP; n = 19), followed by shrimp (n = 10), tree nuts (n = 9), legumes other than peanut (n = 4), and seeds (n = 2); peanut, spinach, celery, buckwheat, wheat, avocado, tomato, fish, meat, and Anisakis caused an anaphylactic reaction in single patients. Among LTP-hypersensitive patients, peach caused 13/19 anaphylactic episodes. Shrimp-allergic patients were significantly older than other patients with food-induced anaphylaxis (p < 0.05), whereas patients allergic to LTP experienced their anaphylactic episodes at a younger age (p < 0.001). The frequency of anaphylaxis among patients sensitized to LTP, shrimp or tree nuts did not differ between northern and central/southern Italy.

CONCLUSION: LTP is the most important allergen causing food-induced anaphylaxis in Italy, peach being the most frequently offending food. Peanut-induced anaphylaxis seems very uncommon. Geographic and environmental differences both between Italy and other countries and within Italy seem to play a relevant role in the pattern of sensitization to foods.