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Biphasic anaphylactic reactions low in patients treated with corticosteroids

The incidence of biphasic anaphylactic reactions appeared to be quite low in patients treated with corticosteroids, according to study results.

Patients with a previous history of drug-related anaphylaxis had the most increased risk for biphasic reactions, according to the researchers.

Byuk Sung Ko, MD, of the department of emergency medicine at Asan Medical Center in Seoul, Korea, and colleagues conducted a retrospective cohort study from January 2007 to December 2014 to analyze the incidence and clinical characteristics of biphasic reactions in patients with anaphylaxis treated with corticosteroids.

The analysis included 415 patients (mean age 48.8 ± 15.7 years; 54.4% women) with anaphylaxis treated with corticosteroids, 2.2% of which had a biphasic reaction.

The most common causes of anaphylaxis in the patients included drugs (45.1%) and food (28.2%).

A history of drug anaphylaxis significantly increased the chance of a patient developing a biphasic reaction (OR = 14.3; 95% CI, 2.4-85.8).

“The present study differs from other studies on biphasic reactions in that drugs were the most common cause of anaphylaxis, whereas previous studies have reported food as the main trigger,” the researchers wrote.

The patients who developed a biphasic reaction experienced it on average 15 hours after complete resolution of initial clinical symptoms.

Several limitations including the study’s retrospective nature occurred, according to the researchers.

“All data were collected from a single center, making it difficult to generalize,” the researchers wrote. “Although most patients received an outpatient follow-up, a small proportion did not, so some cases of biphasic reactions might not have been identified.” – by Ryan McDonald

Disclosure: The researchers report no relevant financial disclosures.