Egg allergy in babies

Egg allergy: the basics

Egg is one of the most common food allergies in babies and young children. Experts estimate that up to 2% of children are allergic to egg (ACAAI). It happens when the immune system overreacts to proteins in egg. Proteins in the white cause most reactions, but it isn’t possible to fully separate white from yolk, so a child with egg allergy avoids both (FARE, ACAAI).

The good news: many children outgrow it (NHS). FARE cites a study in which 71% of children had outgrown egg allergy by age 6, and ACAAI says about 70% outgrow it by age 16.

Introducing egg

The 2021 US and Canadian allergy consensus recommends introducing egg around 6 months, but not before 4 months, along with peanut. The NHS says delaying hen’s eggs beyond 6 to 12 months may increase the risk of egg allergy. In the EAT trial in UK babies, those who ate about 2 g of egg-white protein a week had less egg allergy than those who ate less.

Start with well-cooked egg. The consensus says egg should be introduced in a well-cooked form, and that raw forms are not recommended because they may be more likely to cause a reaction. Good first forms:

• hard-boiled egg, mashed with a little breast milk or formula
• a fully cooked omelet, cut into finger-length strips
• scrambled egg cooked until no runny parts remain

See egg for how to serve it at each age. Offer it on a day your baby is well, at home, when you can watch them for a couple of hours afterward. Start with a small amount, such as a quarter of a teaspoon of mashed hard-boiled egg mixed into a food your baby already eats (ASCIA), then build up.

Keep it going. Once egg goes well, keep it in your baby’s diet. The AAP gives about a third of a well-cooked egg as a regular portion. ASCIA says to include egg at least once a week. See keeping allergens in the diet.

Duck, goose and quail eggs count too. People allergic to hen’s eggs may also react to other birds’ eggs (ACAAI, FARE).

Signs of egg allergy

Symptoms usually start within minutes of eating, but can take up to 2 hours (NHS).

Mild to moderate (ACAAI, NHS):

• hives, a red itchy rash, or eczema getting worse
• mild puffiness of the face or around the eyes
• red, itchy or watery eyes, sneezing or a runny nose
• vomiting once, tummy pain or diarrhea

If it’s only one of these, stop giving egg, stay with your baby and watch them closely for the next couple of hours, and call your pediatrician before you offer it again, in any form. If signs show up in more than one part of the body at once, treat it as anaphylaxis (below).

Don’t rub egg or any other food on your baby’s skin to “test” for allergy. ASCIA says it won’t show whether your baby is allergic, and may make an allergy more likely.

Signs of anaphylaxis are trouble breathing, wheezing or a cough that won’t stop, swelling of the tongue or throat, lips or mouth that suddenly swell, a hoarse cry, turning pale or floppy, becoming very sleepy or unresponsive, or signs in more than one part of the body at once. If you see any of these and your baby has an epinephrine (adrenaline) auto-injector, use it right away, then call for an ambulance. Call 911.Call 999.Call your local emergency number (such as 112 in Europe or 000 in Australia). If you don’t have an auto-injector, call straight away. Keep your baby lying down, never standing or walking (on their side if they’re vomiting, head and shoulders a little raised if breathing is hard), and go to hospital even if they seem better. See signs of anaphylaxis.

How egg allergy is diagnosed

Your doctor or an allergist will ask what happened and may arrange a skin prick test or a blood test for IgE to egg. If the results aren’t clear, the allergist may suggest an oral food challenge: small amounts of egg given under medical supervision, in an office with emergency medicine on hand (ACAAI). Don’t try a challenge at home.

Baked egg

Heating egg for a long time at a high temperature changes the proteins that cause most reactions. FARE says about 70% of children with egg allergy can tolerate baked egg, such as egg cooked into a muffin. But there’s no way to predict which children can (ACAAI), so:

• If your baby has reacted to egg, don’t try baked egg at home until your allergist says so. FARE and ACAAI both say to ask your allergist first, and FARE suggests a formal baked egg challenge.
• If your baby is already eating baked egg without problems, ASCIA says to keep giving those foods, even if they react to lightly cooked egg. If you’re not sure whether your baby tolerates baked egg, talk to your doctor before trying it at home.
• If your baby doesn’t have egg allergy, baked egg is a fine form once they’re eating egg, but the consensus says there’s no evidence it protects against egg allergy by itself. Keep well-cooked egg in the diet too.

Living with egg allergy

Until your allergist tells you otherwise, avoid egg completely, and read labels every time. In the US, egg must be named in plain language on packaged foods (FARE). Egg can turn up in:

• pancakes, waffles, muffins and other baked goods, and French toast
• egg noodles, most ready-cooked pasta (including pasta in soups and ready meals), and some fresh pasta. Dry boxed pasta is usually egg-free, but FARE says it may be made on equipment that also handles egg, so read the label.
• bread with an egg wash on top
• mayonnaise, some salad dressings, custard and ice cream
• canned soups, meatballs and meatloaf, and even some egg substitutes (ACAAI)

Egg can also hide behind names like albumin, ovalbumin, lysozyme or “egg solids” (FARE). An allergy dietitian can help you replace the protein and nutrients egg would give.

Egg allergy is also a reason to talk to your doctor about peanut. NIAID counts babies with egg allergy as high risk for peanut allergy, and early peanut matters most for them. Keep introducing the other common allergens too, as your doctor advises: ASCIA says a baby who is allergic to one food should still have the others. See how to introduce peanut.

Egg and the flu and yellow fever vaccines

Most flu vaccines are made using eggs and contain a tiny amount of egg protein. The CDC says everyone aged 6 months and older with egg allergy should still get a flu vaccine every year, and any flu vaccine suitable for their age can be used. Since the 2023 to 2024 flu season, no extra precautions are recommended for egg allergy, however severe the past reaction. As with any vaccine, it’s given where staff can treat an allergic reaction.

The yellow fever vaccine, which some travelers need, is different: it contains egg protein, and the CDC and WHO list severe egg allergy as a reason not to have it (ACAAI). Ask your doctor before travel.

When to see a doctor

Call your pediatrician or GP if:

• your baby has had any reaction to egg, even a mild one
• you think egg is making your baby’s eczema worse
• your baby has egg allergy and you want to know about baked egg, peanut, or other allergens

Don’t cut egg or other major foods out on your own: talk to your doctor, who may refer you to a dietitian (NHS).

Where US and UK advice differs

• Runny eggs. In the US, the 2021 allergy consensus says undercooked egg isn’t recommended for children under 1, so cook eggs until the white and yolk are firm. The NHS says hens’ eggs with the British Lion stamp are fine for babies raw or lightly cooked. Other hens’ eggs, and duck, goose and quail eggs, should be cooked until the white and yolk are solid. For a first taste, the 2021 US and Canadian allergy consensus recommends well-cooked egg.
• Who should check first. The NHS asks you to talk to your GP or health visitor before introducing egg and other allergens if your baby has eczema or a food allergy, or there’s a family history of allergies, eczema, asthma or hay fever. In the US, the AAP asks you to talk to your pediatrician first if your baby has severe eczema or has had an immediate reaction to a food, and the 2021 consensus says allergy testing before egg isn’t required.