New Study Shows That Infant Anaphylaxis Usually Resolves With One Epinephrine Dose

A recent study has shown that, when infants experience severe allergic reactions, these reactions usually resolve after only one dose of epinephrine. Learn the results of this study, and what they mean for families.

Previously, research on food allergy reactions has shown that severe allergic reactions are the least common in infants, compared to all other age groups. Now, a new study presented at the 2022 American College of Allergy, Asthma, and Immunology (ACAAI) Annual Scientific Meeting shows that, when these severe reactions do occur in infants, they usually resolve after only one dose of epinephrine. Today, we’ll share the results of this study, and what they mean for families with food allergic young children.

The infant anaphylaxis study: A closer look

Anaphylaxis is a severe allergic reaction to a food – or sometimes, to an insect sting or medicine – that requires an epinephrine injection and emergency medical attention. When the symptoms of an allergic reaction are severe, and involve more than one system of the body, the reaction is considered anaphylaxis.

Before this study, there wasn’t much research on what anaphylaxis looks like in infants under 2 years of age, and exactly how it affects babies. This 2022 study, led by Dr. Colleen Shannon and conducted by allergist Dr. Juhee Lee and others, sought to provide more answers.

Let’s break down key elements of the study below:

Who was involved in the study?

169 infants and toddlers with allergies

  • All age 24 months and younger
  • All visited the emergency department because they had symptoms of anaphylaxis
  • Almost all had anaphylaxis because of a food allergy
    • The most common foods that triggered anaphylaxis in these infants were egg (for 26.6%), peanut (for 25.4%), cow’s milk (for 13.6%) and cashew (for 10.1%).

How was the study conducted?

Dr. Shannon, Dr. Lee, and others analyzed the infants’ and toddlers' medical charts from when they visited the emergency department with anaphylaxis.

When they had anaphylaxis, what were the most common symptoms that the infants and toddlers had?

The reported symptoms were in these systems of the body:

  • Skin/mucosal (including symptoms such as hives and swelling): 97.6% of patients
  • Gastrointestinal: 74.6% of patients
  • Respiratory: 56.8% of patients
  • Cardiovascular: 34.3% of patients

How many of the infants and toddlers received epinephrine?

86.4% of patients (146 patients) received an epinephrine injection, the only medicine that can stop anaphylaxis

  • 30.1% of those patients received the epinephrine before visiting the emergency department

What were the main findings of the study?

Out of the patients who received epinephrine, 90.5% only needed one dose of epinephrine to treat the anaphylaxis.

  • Just 9.5% – only 16 of the infants – needed more than one dose of epinephrine.

Only 10.1% of all the patients needed to stay at the hospital for treatment – and none of the patients needed intensive care.

Most of the infants and toddlers only needed emergency department care, and were able to safely go back home after just a few hours of close observation.

Breaking down the findings

The infant anaphylaxis study found that most severe allergic reactions in children under 24 months of age only require one dose of epinephrine, and don’t require any further treatment.

This indicates that infants’ and toddlers’ severe allergic reactions tend to be less severe compared to older children’s severe allergic reactions.

(This finding is in line with results of an earlier study on food allergy reaction severity in children of different ages, which showed that the severity of allergic reactions tends to increase as children get older.)

The study’s results also underscore the importance of always having an epinephrine auto-injector ready to treat a severe allergic reaction, no matter how old the person with the allergy is. It’s vital to recognize the signs of a severe allergic reaction, and inject epinephrine immediately once a reaction turns severe.

Epinephrine is the only medicine that can stop severe allergic reactions, including anaphylaxis – and the sooner it’s injected, the better.

"It's important that infants, just like older children and adults, need quick and accurate diagnosis to make sure their anaphylaxis is treated appropriately. Fortunately, most cases of anaphylaxis in infants seem to resolve with a single dose of epinephrine. The vast majority were able to go home from the emergency department without further intervention." – Dr. Juhee Lee, allergist and senior author of the study

What if my child has a severe allergic reaction?

If your child experiences a severe allergic reaction, inject epinephrine right away. Then, seek emergency medical attention for your child right after you’ve injected the epinephrine.

If your child has experienced severe allergic reaction symptoms previously, take them to an allergist as soon as you can. The allergist will diagnose the allergy, and make a plan to help your family manage your child’s allergies. They can also prescribe an epinephrine auto-injector (an EpiPen, AuviQ, or Adrenaclick) if you don’t already have a prescription for one.

All people with food allergies need two epinephrine auto-injectors on hand at all times, to treat severe allergic reactions – regardless of their age. And all people with food allergies should see an allergist regularly.

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