Anaphylaxis in an urban Belgian emergency department: epidemiology and aetiology

Anaphylaxis is an emergency condition of which reliable epidemiological data are lacking. This study focusses on epidemiology and aetiology of anaphylactic reactions in an urban Belgian emergency department (ED).

Patient data were collected from 04/2009 to 04/2013.During this period, emergency doctors completed a questionnaire for adult patients (>15 years) with anaphylaxis presenting at the ED. Inclusion criteria were based on the Sampson criteria of anaphylaxis. Data were analysed using a Microsoft Excel database.

Anaphylaxis accounted for 0.04% of all emergency visits in this 4-year period. In both women and men, dyspnoea and urticaria were noted most frequently. 51.7% of cases were possibly elicited by foods, 46.1% by drugs and 3.4% by hymenoptera stings. Women more often reported allergic diseases in their personal history. 55.7% of patients, who had a history of allergy, reported a suspected food-related allergy, 24.6% a drug-related allergy and 8.2% a hymenoptera venom-related allergy. In 76.5% of patients who reported a history of food allergy, food was the presumed elicitor of anaphylaxis. For patients with history of drug allergy, 88.2% had a presumed drug anaphylaxis at the time of presentation at the ED. 81% of cases presented with grade 4 or 5 anaphylaxis. With increasing age, the severity of anaphylaxis increased. Higher tryptase levels correlated with a higher grade of anaphylaxis.

In this Belgian urban population, foods and drugs were by far the most common suspected elicitors of anaphylaxis. Personal history of allergic diseases was present in more than half of the cases.