Objective: To study the incidence rate of anaphylaxis in the emergency room of Songklanagarind Hospital.

Method: The medical records of patients diagnosed as having anaphylaxis who visited

Songklanagarind Hospital's Emergency Room from June 1st, 2006 to May 31st, 2008 were reviewed.

Result: The incidence of anaphylaxis was 1 in 686 or 146 in 100,000 cases per year of all patients visited at the emergency room of Songklanagarind Hospital. The presenting symptoms were 142 cases (98.6%) of cutaneous system, 105 cases (74.5%) of respiratory system and one patient required intubation, 41 cases (28.3%) of cardiovascular system and 58 cases (41.4%) of gastrointestinal system. The most common causes of anaphylaxis were food (33.8%), medicine (22.1%) and insect stings (13.1%).

Conclusion: The incidence of anaphylaxis at the emergency room of Songklanagarind Hospital was 146 in 100,000 cases per year. The most common cause of anaphylaxis was food.