Anaphylaxis In Babies: Symptoms, Causes And Treatment

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An anaphylactic reaction or anaphylaxis in babies is a severe allergic reaction and can lead to swelling in various parts of the body due to leakage of fluids. It can also cause troubled breathing and increased heart rate. These physiological changes are due to histamines released during severe allergies. Our cells release histamine in response to the triggers or allergens (1).

Anaphylaxis may occur within seconds or even hours after exposure to allergens. It is a life-threatening condition that requires prompt medical attention (2) (3).

Read on as in this post we provide information about the signs, symptoms, causes, and management of anaphylaxis in babies.

Signs Of Anaphylaxis

The signs may appear in seconds, minutes, or hours after exposure to the allergen. In most cases, they appear quickly. The signs and symptoms could vary in each baby based on their sensitivity to the allergen and the quantity of allergen.

Below are some of the common signs of anaphylaxis in babies(2)(3).

  • Sneezing or stuffy and runny nose
  • Excess drooling
  • Swelling of lips and tongue
  • Tightness or swelling of the throat, tongue, or uvula
  • Inconsolable crying
  • Hoarseness of voice, noticeable while crying
  • Trouble breathing
  • Wheezing sound while breathing
  • Hives or rashes on the body
  • Reddish or bluish skin color
  • Severe skin itching
  • Nausea and vomiting
  • Diarrhea
  • Loss of bladder control
  • Fussiness
  • Drowsiness and lethargy
  • Weak pulse

Risk Factors For Anaphylaxis In Babies

Anaphylaxis may occur without any predisposition or presence of risk factors. However, if your baby has one or more of the following conditions, they may have a higher risk of experiencing anaphylaxis (2).

  • Allergies
  • Asthma
  • A family history of anaphylaxis
  • A previous history of anaphylaxis

Causes Of Anaphylaxis In Babies

An anaphylactic reaction happens as a response to allergen contact. Each baby may be sensitive to a different allergen. The following are the commonly identified allergens(4)(5).

1. Foods

Babies older than six months are usually at a higher risk of anaphylaxis due to food items. Infants younger than six months may have a risk if they consume infant food or formula made with potential allergens, such as soy and milk. Below are food items that are commonly associated with allergy and anaphylaxis.

  • Legumes, such as peanuts, beans, lentils, and peas
  • Tree nuts
  • Fish
  • Shellfish
  • Eggs
  • Milk
  • Wheat
  • Soy
  • Mushrooms

Any fruit and vegetable could also be a potential allergen, and it could depend on the sensitivity of the baby towards a specific fruit or vegetable.

2. Insect stings

The venom and saliva of the following insects could trigger anaphylaxis due to a sting or bite.

  • Bees
  • Wasps
  • Hornets
  • Yellow-jackets
  • Fire ants

3. Medicines

The reaction of certain antibiotics, such as penicillin may depend on various factors, including the dosage and whether it cross-reacts with other potential allergens.

4. Miscellaneous

Anaphylaxis may also occur due to compounds found in everyday items, such as toys, and substances found in nature, such as pollen. Below are some of the common potential allergens.

  • Dyes in clothes, toys, and food
  • Latex
  • Pollen
  • Aerosol-based compounds

Diagnosis Of Anaphylaxis In Babies

A pediatrician will diagnose anaphylaxis based on the symptoms and allergen-contact history, such as if the baby came in contact or consumed a potential allergen within hours of developing symptoms. The doctor may also ask for medical history to corroborate their findings.

The healthcare provider will note the following to confirm a diagnosis of anaphylaxis (2).

  • Known history of allergy
  • Any episode of allergic reaction to a known or possible allergen
  • Symptoms of the baby
  • Physical symptoms
  • Blood pressure reading
  • Blood tests may be conducted in rare cases

How To Respond To An Anaphylactic Reaction?

The anaphylactic reaction should be immediately dealt with as it might be fatal. The following steps must be followed if you notice an anaphylactic reaction in your baby(6).

  • Epinephrine is the first line of treatment as it quickly reverses the life-threatening symptoms of anaphylaxis. The doctor may prescribe epinephrine auto-injectors for your baby if your baby is at a high risk of developing anaphylaxis or has a previous history.
  • Epinephrine is available in auto-injectable syringes. The muscle in the outer part of the thigh is usually the best place to inject it.
  • A second dose may be needed if the symptoms do not subside in one dose. Carry two doses of epinephrine every time.
  • After administering epinephrine, note the exact time of administration and call the local emergency number.
  • Call an ambulance with epinephrine shots in case you do not have epinephrine injections handy.
  • Lay the baby on their back. If the baby vomits or has trouble breathing, turn the baby to their side.
  • You may administer other medications such as a bronchodilator and antihistamine prescribed by the doctor. However, do not use these medications as a substitute for epinephrine.

Treatment For Anaphylaxis In Babies

The best treatment of anaphylaxis is to subdue the symptoms before they turn into complications or cause severe discomfort to the baby. This approach is best explained by the mnemonic REACT (7).

1. R: Recognizing the symptoms of anaphylaxis

Stay alert and remember the usual signs of anaphylaxis in babies. If your baby is at a higher risk of anaphylaxis, educate other people at home and at the baby’s daycare about the steps to identify the symptoms and handle the situation.

2. E: Epinephrine administration

Epinephrine comes in auto-injectable syringes. EpiPen or AuviQ are some of the common trade names for epinephrine auto-injectors. It is available on prescription only. The outer part of the thigh muscle is usually the best place to administer epinephrine.

3. ACT: Activate the emergency response

Keep the following steps in mind.

  • If your baby’s pediatrician has given you an allergy action plan, follow the steps included in that plan.
  • After you administer the epinephrine, call the local emergency number immediately.
  • Lay the baby on their back or side until the ambulance arrives.
  • Take the baby to a hospital as soon as the ambulance arrives.

Do note it is best to administer epinephrine to the baby if you are unsure if it is an anaphylactic shock. If the baby is taken to the hospital emergency, they may receive supportive treatment, such as additional epinephrine, IV fluids, and oxygen support.

Prevention Of Anaphylaxis In Babies

The best way to prevent anaphylaxis in babies is to keep the baby away from any known or potential allergens. Inform the baby’s daycare and caregivers about any known food allergies. Exposure to insect bites and pollen can be avoided by dressing the baby in protective clothing, using insect mesh on windows, and avoiding parks or places where there could be pollen and insects. If the baby is allergic to dye, latex, or any other compounds, get rid of the item and do not use it again (2).

Anaphylaxis reactions can be unpredictable, and it is essential to memorize the signs to react early. Do not delay asking for medical help if your baby shows any symptoms of anaphylaxis. Speak to your baby’s healthcare provider to learn the management and prevention of anaphylaxis in your baby.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. Kevin McLendon and Britni T. Sternard, Anaphylaxis; StatPearls; U.S. National Library of Medicine
2. Anaphylaxis in Children; Cedars-Sinai
3. Anaphylaxis in Infants & Children; American Academy of pediatrics
4. Anaphylaxis; ACAAI
5. Richard F. Lockey, Anaphylaxis: Synopsis; World Allergy Organization
6. Anaphylaxis; Cleveland Clinic
7. Michael Pistiner, How to Spot Anaphylaxis in Babies; Massachusetts General Hospital
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Dr. Supriya Mahajan

Dr. Supriya Mahajan is a pediatrician and pediatric hepatologist with nine years of experience. She completed her MBBS from Shyam Shah Medical College and diploma from the National Board of Education, New Delhi. She went on to gain specialization in the gut and liver-related diseases in children from the Institute of Liver and Biliary Sciences and MRCPCH 1, 2 from... more

Dr. Ritika Shah

Dr. Ritika Shah is a dental surgeon with more than seven years of clinical experience across various cities in India. During her clinical practice, pediatric dentistry was her particular area of interest, and she constantly thrived to inculcate the latest advancements in the field of dentistry into her practice. Dr. Shah's deep interest in the well-being of babies and children... more