Children who present with a severe anaphylactic reaction are two to three times more likely to develop a second delayed, or late-phase, reaction, Dr. Waleed Alqurashi and his colleagues reported.
Their retrospective study found that of 484 children who came to the emergency department for anaphylaxis, 15% developed a biphasic reaction. Most of these (69%) were respiratory and/or cardiovascular; half required epinephrine (Ann. Allerg. Asth. Immunol. 2015 [doi.org/10.1016/j.anai.2015.05.013]).
Michele Sullivan/Frontline Medical News
Dr. Waleed Alqurashi
Dr. Alqurashi of the pediatric department at the University of Ottawa and his associates identified five independent predictors of a biphasic reaction: age 6-9 years (odds ratio, 3.6); a delay in presentation of more than 90 minutes after the onset of the initial reaction (OR, 2.58); wide pulse pressure at triage (OR, 2.92); requiring more than one epinephrine dose for initial reaction (OR, 2.7); and needing inhaled beta-agonists at the ED (OR, 2.39).
Children with these characteristics should stay for observation, rather than being discharged when their initial reactions are stabilized, the authors wrote.
“This period should be individualized and based primarily on the degree of severity of the initial anaphylactic reaction. Given the relatively high sensitivity of the present predictors, children with mild anaphylaxis who do not match any of these predictors could be considered for early disposition from the ED (less than 6 hours timed from the onset of the anaphylactic reaction) as long as an appropriate counseling has been provided,” the investigators said. Nonetheless, Dr. Alqurashi and his associates think large-scale prospective pediatric studies are necessary to validate these predictors.
Dr Alqurashi and his associates have no financial disclosures.