Hives after a first taste of egg, eczema that will not settle, or sneezing that never seems to stop. It is natural to wonder whether your baby has an allergy. Allergies in babies are fairly common, especially in families with eczema, asthma or hay fever. Knowing the signs, the common triggers and the emergency warning signs helps you respond calmly.
Quick answer: allergies in babies
- Most common food allergens: cow’s milk, egg, peanut, tree nuts, wheat, soy, fish, shellfish and sesame.
- Typical signs: hives, swelling, vomiting or eczema flares soon after a trigger.
- Introduce allergens early, around 6 months, one at a time.
- Anaphylaxis is an emergency: breathing difficulty, swelling of the tongue or throat, floppiness.
Food allergy symptoms
- Immediate (within 2 hours): hives, redness, swelling of the lips, face or eyes, vomiting, coughing, wheezing.
- Delayed (hours to days): eczema flares, reflux, diarrhoea, blood or mucus in poo, poor growth. Often linked to cow’s milk protein allergy.
Environmental allergies
Allergies to dust mites, pets or pollen can cause a runny nose, sneezing and itchy eyes, but they are less common in young babies. See allergy vs cold vs flu in babies.
Introducing allergens safely
- Start around 6 months, once your baby is eating other solids.
- Offer one new allergen at a time, in a small amount, at home and earlier in the day.
- Use safe forms: well-cooked egg, smooth peanut butter thinned into food, never whole nuts.
- Keep offering each tolerated allergen regularly, a few times a week.
- Talk to your doctor first if your baby has severe eczema or a known food allergy.
See best first foods for babies and baby eczema.
Signs of anaphylaxis: call emergency services
- difficulty breathing, noisy breathing or wheezing
- swelling of the tongue or throat
- persistent coughing or a hoarse cry
- pale, floppy or unusually sleepy
- collapse
When to talk to your doctor
- any reaction after a food, even mild, before offering it again
- eczema that is hard to control
- ongoing vomiting, diarrhoea or blood in poo
- poor weight gain
- symptoms that seem linked to pets, dust or seasons
Frequently asked questions
Can allergies be prevented?
Early, regular introduction of allergens like egg and peanut lowers the risk of developing those allergies for many babies.
Will my baby outgrow a food allergy?
Many children outgrow milk and egg allergies. Peanut and tree nut allergies are more likely to last.
Should I avoid allergens while breastfeeding?
Not usually. Only cut out foods if your doctor advises it.
Sources
- NHS: Food allergy; Anaphylaxis
- American Academy of Pediatrics, HealthyChildren.org: Food Allergies in Children
- NIAID: Guidelines for the prevention of peanut allergy
This guide is general information, not medical advice. If you suspect an allergy, talk to your doctor. In an emergency, call your local emergency number.