Biphasic reactions in patients with anaphylaxis treated with corticosteroids.
BACKGROUND
Although the incidence of anaphylaxis is rapidly increasing, the clinical characteristics and associated factors of a biphasic reaction are unclear.


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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Byuk Sung
BS
Ko
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea. Electronic address: wonpia73@naver.com.
Won Young
WY
Kim
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Seung Mok
SM
Ryoo
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Shin
S
Ahn
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Chang Hwan
CH
Sohn
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Dong-Woo
DW
Seo
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Yoon-Seon
YS
Lee
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Kyoung Soo
KS
Lim
Division of Allergy and Clinical Immunology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Tae-Bum
TB
Kim
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000707:Anaphylaxis / Q000188:drug therapy* / Q000453:epidemiology; D015331:Cohort Studies; D004342:Drug Hypersensitivity / Q000503:physiopathology; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D004837:Epinephrine / Q000627:therapeutic use; D005260:Female; D005512:Food Hypersensitivity / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
D000305:Adrenal Cortex Hormones; D004837:Epinephrine