Background: Anaphylaxis is a potentially fatal condition, and many patients experience recurrence.

Objective: We report the incidence of first recurrence of anaphylaxis in our series and examine the risk factors associated with recurrence.

Methods: A validated questionnaire was sent to 1512 patients and completed by 887. The chosen definition of anaphylaxis was that of the National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network Symposium. We evaluated the incidence of first recurrence of anaphylaxis overall and by subtype (eg, drugs and foods) and attempted to determine associated risk factors.

Results: The total incidence rate of the first recurrence of anaphylaxis (same subtype) was 3.2 episodes per 100 person-years (95%CI, 2.83-3.63). Incidence was lower in drug anaphylaxis (2.0 episodes per 100 person-years) than in latex and food anaphylaxis (8.6 and 5.6 episodes per 100 person-years, respectively). Cox and ordinal logistic regression models revealed that a first recurrence was less likely with drug anaphylaxis than with food anaphylaxis. The risk of experiencing 1 or more recurrences was higher for foods, exercise, and idiopathic causes than for the other subtypes.

Conclusions: The incidence rate for a first recurrence of the same subtype of anaphylaxis was 2 to 6 times lower than that published by other authors. Recurrence of anaphylaxis is more common in subtypes with an increased prevalence of atopy (food, idiopathic, latex) than in other subtypes (drugs, Anisakis). Consequently, particular attention should be paid to prevention and care in this population.

Key words: Anaphylaxis. Atopy. Incidence. First. Recurrence. Risk. Factors.