Features of patients with anaphylaxis admitted to a university hospital

Background: Anaphylaxis in hospitalized patients has been infrequently reviewed. There are few studies of anaphylaxis from Asian countries. Objective: To describe the clinical characteristics of patients with anaphylaxis admitted to Siriraj Hospital. Methods: The medical records of 101 patients admitted with clinical anaphylaxis between January 1, 1999, and December 31, 2004, were reviewed. Data were analyzed using the chi(2) test. Results: The annual occurrence of anaphylaxis increased from 9.16 per 100,000 admitted persons in 1999 to 55.45 per 100,000 admitted persons in 2004. The case fatality rate was 0.19 per 100,000 admitted persons. The mean +/- SD age was 23.73 +/- 21.84 years. Males experienced more anaphylaxis than females in pediatric patients and vice versa in adult patients. Biphasic anaphylaxis was found in 7% of pediatric and 2% of adult patients. Anaphylaxis occurred in the hospital in 37% of patients. Involved systems were cutaneous (86%), respiratory (80%), cardiovascular (52%), and oral and gastrointestinal (36%). Identifiable causes were drugs (50%), foods (24%), idiopathic (15%), and insect stings/bites (11%). Epinephrine was given to 77% of the patients. Conclusions: We report the clinical characteristics of patients with anaphylaxis admitted to a university hospital. Knowing the clinical features will raise physician awareness of this condition.