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Medline ® Abstracts for References 90,91

of 'Anaphylaxis: Emergency treatment'

Outcomes of allergy/immunology follow-up after an emergency department evaluation for anaphylaxis.
Campbell RL, Park MA, Kueber MA Jr, Lee S, Hagan JB
J Allergy Clin Immunol Pract. 2015 Jan;3(1):88-93. Epub 2014 Sep 22.
BACKGROUND: Anaphylaxis guidelines currently recommend referring patients with anaphylaxis seen in the emergency department (ED) to an allergist for follow up.
OBJECTIVE: The objective of our study was to evaluate outcomes of allergy/immunology follow-up after an ED visit for anaphylaxis.
METHODS: A retrospective health records review was conducted from April 2008 to August 2012. Charts were reviewed independently by 2 allergists to determine outcomes. Descriptive statistics with corresponding 95% CIs were calculated.
RESULTS: Among 573 patients seen in the ED who met anaphylaxis diagnostic criteria, 217 (38%) had a documented allergy/immunology follow-up. After allergy/immunology evaluation, 16 patients (7% [95% CI, 5%-12%]) had anaphylaxis ruled out. Among those with an unknown ED trigger (n = 74), 24 (32% [95% CI, 23%-44%]) had a trigger identified; and, among those who had a specific suspected ED trigger (n = 143), 9 (6%[95% CI, 3%-12%]) had a trigger identified in a category other than the one suspected in the ED, and 28 (20% [95% CI, 14%-27%]) had an unknown trigger. Thus, there were a total of 77 patients (35% [95% CI, 29%-42%]) who had an alteration in the diagnosis of anaphylaxis or trigger after allergy/immunology evaluation. Four patients (2% [95% CI, 0.7%-4.6%]) were diagnosed with a mast cell activation disorder, and 13 patients (6% [95% CI, 4%-10%]) underwent immunotherapy or desensitization.
CONCLUSION: Overall, 35% of the patients with suspected anaphylaxis in the ED had an alteration in the diagnosis or suspected trigger after allergy/immunology evaluation. These results underscore the importance of allergy/immunology follow-up after an ED visit for anaphylaxis.
Department of Emergency Medicine, Mayo Clinic, Rochester, Minn. Electronic address: campbell.ronna@mayo.edu.
Time of Onset and Predictors of Biphasic Anaphylactic Reactions: A Systematic Review and Meta-analysis.
Lee S, Bellolio MF, Hess EP, Erwin P, Murad MH, Campbell RL
J Allergy Clin Immunol Pract. 2015 May-Jun;3(3):408-16.e1-2. Epub 2015 Feb 11.
BACKGROUND: A biphasic reaction is a potentially life-threatening recurrence of symptoms after initial resolution of anaphylaxis without re-exposure to the trigger. The infrequent nature of these reactions has made them difficult to study and predict.
OBJECTIVE: The aim of this study was to evaluate the time of onset and predictors of biphasic anaphylactic reactions.
METHOD: Original research studies that described biphasic reactions in case series or cohort studies were included. Studies that did not describe biphasic reactions and case series with less than 2 biphasic reactions were excluded. Data sources included MEDLINE, EMBASE, Web of Science, and Scopus from inception to January 2014 and bibliographies of included articles. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for dichotomous variables. Inconsistency among studies was assessed with the I(2) statistic.
RESULTS: Twenty-seven observational studies that enrolled 4114 patients with anaphylaxis and 192 patients with biphasic reactions were included. The median time of symptom onset was 11 (range 0.2 to 72.0) hours. Food as the inciting trigger was associated with decreased risk (pooled OR 0.62, 95% CI: 0.4 to 0.94, I(2) = 0%) and an unknown inciting trigger with increased risk (pooled OR 1.72, 95% CI: 1.0 to 2.95, I(2) = 61%). Initial presentation with hypotension (pooled OR 2.18, 95% CI: 1.14 to 4.15, I(2) = 79%) was also associated with the development of a biphasic reaction.
CONCLUSION: Biphasic anaphylatic reactions were less likely among patients with food as an inciting trigger. Patients who present with hypotension or have an unknown inciting trigger may be at increased risk of a biphasic reaction. Clinicians should tailor observation periods for patients individually based on clinical characteristics.
Department of Emergency Medicine, Mayo Clinic Health System, Mankato, Minn. Electronic address: Lee.Sangil@mayo.edu.