Different clinical features of anaphylaxis according to cause and risk factors for severe reactions

Anaphylaxis is a life-threatening allergic reaction. Several studies reported different anaphylactic reactions according to the causative substances. However, a comparison of anaphylaxis for each cause has not been done. This study was conducted to identify common causes of anaphylaxis, characteristics of anaphylactic reaction for each cause and to analyze the factors related to the severity of the reaction.

Medical records of patients who visited the emergency room of Ewha Womans University Mokdong Hospital from March 2003 to April 2016 and diagnosed with anaphylactic shock were retrospectively reviewed. We compared the clinical features of anaphylaxis according to the cause. In addition, the severity of anaphylaxis was analyzed and contributing factors for severe anaphylaxis were reviewed.

A total of 199 patients with anaphylaxis were analyzed. Food was the most common cause (49.7%), followed by drug reaction (36.2%), bee venom (10.1%), and unknown cause (4.0%). Cardiovascular symptoms of syncope and hypotension were more common in drug-induced anaphylaxis. The incidence of severe anaphylaxis was the highest in anaphylaxis due to drugs (54.2%). Urticaria and other skin symptoms were significantly more common in food-induced anaphylaxis. Risk factors for severe anaphylaxis included older age, male, and drug-induced one. Epinephrine treatment of anaphylaxis was done for 69.7% and 56.9% of patients with food-induced and drug-induced anaphylaxis, respectively.

More severe anaphylaxis developed with drug treatment and in males. Low rate of epinephrine prescription was also observed. Male patients with drug induced anaphylaxis should be paid more attention.