Incidence of anaphylaxis in the emergency department of a general hospital in Milan

Objective: To evaluate incidence and causes of anaphylactic reactions in the emergency room (E.R.) of a general hospital in Milan during a 2-year period. Methods: We retrospectively studied the computerized records of patients discharged from an E.R. with a diagnosis of anaphylactic reaction. Anaphylaxis was established on the presence of at least two cutaneous, respiratory, gastrointestinal or cardiovascular system symptoms. Results: During 1997 and 1998, out of 38 685 patients referred to the E.R., 13 had severe anaphylaxis with loss of consciousness (LOC) and 127 had anaphylactic symptoms, without LOC. Of the 13 patients with LOC, a possible cause was identified in 12 (five foods, six drugs, one hair dye). In the other 127 patients anaphylaxis was related to foods in 49 cases (38.5%), drugs in 44 (34.6%), unknown causes in 29 (22.8%), hymenoptera stings in two (1.5%), and other causes in three (2.3%). Conclusions: The incidence of anaphylactic reactions was 0.4% and mainly affected females and atopic subjects. Foods, particularly fruits and vegetables, appeared to be the most important cause; other important causes were non steroidal antiinflammatory drugs and p-lactam antibiotics.