Background: Alergológica-2005 is a cross-sectional study carried out in Spain in 4991 new patients prospectively recruited in allergy clinics.

Objective: To describe the characteristics of food allergic patients included in Alergológica-2005.

Results: Food allergy was diagnosed in 369 subjects (7.4%, 95% CI, 6.7%-8.1%). The most common offending foods were fruits (33.3% of cases), nuts (26%), shellfi sh (22%), egg (16%), milk (13.9%) and fi sh (9.8%). Rosaceae fruits and crustaceans elicited 23.6% and 18.7% of the reactions, respectively. Milk and egg were the most common foods in patients < 5 years of age, whereas fruits and nuts were the most prevalent foods in patients over 5 years. The most frequent manifestations included skin reactions (65.3%), oral allergy syndrome (33.6%), digestive symptoms (24.7%) and anaphylaxis (17.9%). The clinical presentation differed among foods. Prick-tests were carried out more frequently than serum immunoglobulin E (IgE) determinations (95.9% vs. 65%). Oral challenges were performed in 13% of patients, and 72.3% of these were open. Food allergy was diagnosed on the basis of medical history and positive IgE in 60.2%
of the patients, ranging from 13.7% for milk to 75% for cereals. The self perception of patients’ quality of life was lower than that of the 75% of Spanish reference population.

Conclusion: Food allergy is diagnosed in 7.4% of the patients seen in allergy clinics across Spain, and has an important impact on the quality of life of patients. The foods involved in reactions change with age. The clinical presentation changes with the food, although the skin is the most frequently affected organ.

Key words: Allergy Diagnosis. Food. Fruit. Oral challenge. Nuts. Prevalence. Spain.