Anaphylaxis: a review of 601 cases

In most cases, the cause of anaphylaxis is undetermined. Women are affected more commonly than men. Systemic mastocytosis should be considered in cases of idiopathic anaphylaxis, and patients with a history of atopy are at an increased risk of developing anaphylaxis. Patients are more reliably carrying epinephrine as a result of changes in physician instructions. Finally, anaphylactic episodes tend to decrease in frequency and severity with time.