Infant food allergy: signs and next steps

A food allergy is an immune reaction to a food protein. Symptoms may include hives, facial swelling, vomiting, diarrhoea, coughing, wheezing, or sudden unsettled behaviour after eating. A rash or tummy upset can have other causes, so one symptom alone cannot confirm food allergy. Some infants may develop an itchy mouth or throat, although a baby may show this by refusing food or becoming distressed.

A severe reaction, called anaphylaxis, can affect breathing or circulation and may involve a swollen tongue, noisy breathing, marked paleness, limpness, or collapse. This is an emergency. The timing, food, amount, preparation, symptoms, and recovery all help a clinician assess the pattern.

Stop offering the suspected food and keep the packaging or a clear ingredient list. Note the time, symptoms, and what happened next; photographs can help document skin changes. Do not repeatedly test the food at home, remove broad food groups without guidance, or rely on an internet food list for diagnosis.

Arrange a medical review for assessment and a feeding plan. A clinician may recommend allergy testing and explain whether and how foods should be reintroduced. Continue safe, suitable feeding unless your healthcare team advises otherwise, because unnecessary restriction can affect nutrition and feeding confidence.

Call emergency services immediately for breathing difficulty, wheezing, throat or tongue swelling, blue or grey colour, collapse, extreme sleepiness, or repeated vomiting with pale or limp behaviour. Use prescribed emergency medicine exactly as instructed and do not wait to see whether symptoms settle. Even if the infant improves, urgent medical review is needed after a severe reaction.

Ask whether the reaction fits food allergy, which foods should be avoided, how to read ingredient labels, and whether an emergency plan or prescribed medicine is needed. Discuss safe introduction of other foods, nutrition, allergy testing, and what symptoms should trigger emergency treatment.