News Release 

Antihistamine use for anaphylaxis symptoms linked with delay seeking emergency treatment

Research shows a majority of families whose children were hospitalized for anaphylaxis turned first to antihistamines, which can't prevent allergic reaction from becoming fatal

American Academy of Pediatrics


IMAGE: Anaphylaxis is highly likely when any ONE of the following three criteria is fulfilled. view more 

Credit: Evan Wiley, MD

NEW ORLEANS - New research suggests that giving antihistamine medicine to a child experiencing anaphylaxis--a sudden and severe allergic reaction that can quickly be fatal--usually does more harm than good by delaying emergency treatment.

A research abstract, "The Association of Antihistamine Administration and Delayed Presentation for Care in Pediatric Patients Admitted with Anaphylaxis," will be presented on Sunday, Oct. 27, during the American Academy of Pediatrics (AAP) 2019 National Conference & Exhibition in New Orleans.

"Anyone experiencing symptoms of anaphylaxis, which can constrict airways and circulation, should seek medical care immediately and use an epinephrine auto-injector if they have been prescribed one," said Evan Wiley, MD, the abstract's lead author and a pediatric resident at Jacobi Medical Center in New York. However, he said, many families first turn to antihistamines and wait to see if they might ease the allergic reaction--a risky mistake.

"While the use of antihistamines might help some allergic symptoms such as rash or itching, those medications will not prevent death from anaphylaxis," Dr. Wiley said. "It is important for patients with anaphylaxis to seek immediate medical care, since the only proven lifesaving treatment is epinephrine, and any delay in receiving appropriate treatment can be fatal."

For the study, Wiley and his research team reviewed the medical records for patients ranging in age from 8 months to 20 years admitted to a community hospital pediatric intensive care with a diagnosis of anaphylaxis between July 2015 and January 2019. They discovered that the majority of patients (72%) who first took antihistamines at home for their symptoms delayed seeking medical care, compared to only 25% of patients who did not take antihistamines.

"What we found was that administration of antihistamine was associated with 7.45 times increased odds of delay in seeking medical care," Dr. Wiley said. He added that more research is needed to confirm this association, but the findings suggest an urgent need to educate families to administer epinephrine and call 911 as soon as anaphylaxis symptoms begin.

Food allergies, the most common trigger for anaphylaxis, are on the rise in U.S. children, according to the Centers for Disease Control and Prevention.

Dr. Wiley will present an abstract of the study, available below, at 8 a.m. in Grand Ballroom A of Hilton New Orleans Riverside. More information about anaphylaxis is available on the American Academy of Pediatrics parenting website,

In addition, Dr. Wiley will be among highlighted abstract authors who will give brief presentations and be available for interviews during a press conference on Saturday, Oct. 26, starting at 12:30 p.m. in rooms 208-209 (Press Office) of the Ernest N. Morial Convention Center. During the meeting, you may reach AAP media relations staff in the National Conference Press Room at 504-670-5406.

Please note: only the abstract is being presented at the meeting. In some cases, the researcher may have more data available to share with media, or may be preparing a longer article for submission to a journal.


The American Academy of Pediatrics is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists dedicated to the health, safety and well-being of infants, children, adolescents and young adults. For more information, visit Reporters can access the meeting program and other relevant meeting information through the AAP meeting website at

Abstract Title: The Association of Antihistamine Administration and Delayed Presentation for Care in Pediatric Patients Admitted with Anaphylaxis

Evan Wiley, MD, presenting author

Introduction: It is estimated that 1.5 per 100,000 children are hospitalized for food associated anaphylaxis in the United States. Anaphylaxis, as defined by the World Allergy Organization (WAO) criteria (Table1), can be rapidly fatal, but the administration of epinephrine can prevent mortality. Antihistamines relieve some anaphylaxis symptoms but do not prevent mortality. Anecdotal reports suggest patients commonly delay administering epinephrine, hoping an antihistamine will resolve their symptoms, but the role of antihistamines in delayed presentation for medical care is unknown. Objective: To determine the association between home administration of antihistamines prior to hospital presentation and delayed seeking of care in children admitted with anaphylaxis. Methods: Retrospective chart review was performed for patients admitted with a diagnosis of anaphylaxis to the pediatric hospital floor or PICU at a community hospital from 7/1/15 - 1/15/19. Inclusion criteria included age less than 21 years and symptoms meeting WAO criteria for anaphylaxis prior to presenting for care. Patients who met WAO criteria only after seeking care or developed symptoms where a healthcare professional was immediately available (e.g. school or camp) were excluded. Charts were reviewed for variables of interest. Demographic data (age, sex) was collected. The primary exposure variable was antihistamine administration by patient or caregiver prior to hospital presentation. The primary outcome variable was any delay in immediately seeking care once the patient met WAO criteria for anaphylaxis. Potential confounding variables were identified (gender, availability of epinephrine at home, administration of epinephrine prior to presentation for care, and history of allergy), but none met criteria for confounding. For all variables, frequencies and chi square were calculated (Table 2), and a final binomial logistic regression model was created with the primary exposure and outcome variables. No potential confounders were included in the final model as none met criteria for confounding. Results: 169 admissions with a diagnosis of anaphylaxis were identified: 79 met criteria for inclusion while 90 did not. The age range was 8 months to 20 years, and 57% were male. In patients administered antihistamines (32 total), 72% delayed seeking care; of those not administered antihistamines (48 total) 25% delayed seeking care (p<.001) (Table 2). Administration of antihistamine was associated with 7.45 times increased odds of delay in seeking care (OR 7.45 [2.71, 20.50], p<0.001). Discussion: Home administration of antihistamines for anaphylaxis prior to hospital presentation was significantly associated with an increased odds of delay in immediately seeking care. Delayed presentation for anaphylaxis can delay epinephrine administration and increase mortality. Future studies are needed to confirm this association, but the findings suggest the need to optimize patient education on the limited role of antihistamines for anaphylaxis and the need for immediate presentation to care at anaphylaxis onset.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.