D2.264 - Food-induced Anaphylaxis: Characterization and Trends of a Four-year Single-center Survey

Anaphylaxis is a clinical emergency, and the most severe form of allergic disease. In recent years, the triggers have evolved, with food allergies becoming increasingly prevalent, especially in childhood.

The goal of this work was to improve epidemiological knowledge of food-induced anaphylaxis (FIA), in both children and adults with FIA diagnosis confirmed by an allergy specialist.

A single-center longitudinal study was conducted in our Immunoallergy department over the last 4 years, using a voluntary notification system, with characterization of observed patients (pts) with clinical history of FIA. This notification was based on a detailed questionnaire applied by allergists regarding etiology, clinical manifestations, diagnosis, management and recurrence of anaphylaxis.

A total of 145 pts were included: mean age 17.1 (±16.9) years, 65% under 18 years and 2% elderly; 52% were male; and 46% had asthma. The majority of first FIA episodes occurred at preschool age (63%): median age 3 years (ranging from 1 month to 64 years). Most reactions occurred at home (66%); 21% at restaurants, and 11% at school.

The primary trigger foods were tree nuts (26%), milk (22%), shellfish (15%), fresh fruits (14%), egg (14%), peanut (11%), fish (10%), wheat (2%) and sesame (1%). Regarding the age at the first FIA episode: in infants, milk and egg were the most common triggers; in preschoolers, tree nuts; and in adults, shellfish.

Symptoms were mainly mucocutaneous (99%) and respiratory (83%), followed by gastrointestinal (54%), cardiovascular (32%) and laryngeal edema (28%); 89% developed within 30 minutes of trigger exposure. While most pts (83%) were admitted to the emergency department, adrenaline was administered to only 45%.

Recurrence of FIA occurred in 44% of pts (≥3 episodes in 22%): milk-19 pts, tree nuts-15, shellfish-7, egg-7, fresh fruits-6, peanut-5, fish-4, and wheat-1. An adrenaline autoinjector device was used in 12% of the pts.

In our population, tree nuts, milk, and shellfish were the leading elicitors of FIA, with cow’s milk being the main cause in children. Compared to previous studies, namely the Portuguese nationwide anaphylaxis registry published, there is an increase in tree nuts allergy which presents as the foremost cause of FIA. Adrenaline remains underused, and recurrence of FIA is frequent, emphasizing the importance of optimizing strategies for the prevention, diagnosis, and therapeutic management of FIA.