Biphasic reactions in patients with anaphylaxis treated with corticosteroids.

Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology

PubMedID: 26276313

Ko BS, Kim WY, Ryoo SM, Ahn S, Sohn CH, Seo DW, Lee YS, Lim KS, Kim TB. Biphasic reactions in patients with anaphylaxis treated with corticosteroids. Ann Allergy Asthma Immunol. 2015;.
Although the incidence of anaphylaxis is rapidly increasing, the clinical characteristics and associated factors of a biphasic reaction are unclear.

To determine the incidence and clinical characteristics of biphasic reactions in patients with anaphylaxis treated with corticosteroids.

A total of 655 patients with anaphylaxis visiting the emergency department of a tertiary teaching hospital from January 2007 through December 2014 were analyzed. Patient characteristics, triggers, symptoms and signs, in-hospital management, and disposition were recorded. A biphasic reaction was defined as the development of anaphylaxis after complete resolution of the initial reaction without further exposure to the offending agent within 7 days. Univariate and multivariate analyses on the predictors of the biphasic reaction were performed.

Of the 415 patients with anaphylaxis treated with corticosteroids, 9 patients (2.2%) developed a biphasic reaction. The mean age was 48.4 years, and 221 patients (54.4%) were women. The median time from complete resolution of initial clinical symptoms to occurrence of the biphasic reaction was 15 hours (range 1-45). History of drug anaphylaxis (odds ratio 14.3, 95% confidence interval 2.4-85.8) was a contributing factor to the development of the biphasic reaction.

The incidence of biphasic reactions was 2.2% in patients treated with corticosteroids and those with a history of drug anaphylaxis were at greater risk.