Allergy signs after a new food

When does a reaction start?

Allergic reactions usually start within a few minutes of a new food. Sometimes signs can take up to 2 hours to appear. In some cases, such as cow's milk allergy, signs can be delayed by up to 3 days. Try a new food when your baby is healthy and at home. Choose a time when you can watch them closely afterward.

Mild signs

A few hives may appear around the mouth or face. You may see a new redness, an itchy rash or worsening eczema. Sneezing, a runny nose or watery eyes can also occur. In this case, stop giving the new food and talk to your child's doctor. Keep watching your baby, because reactions can get worse.

Serious signs

Swelling of the lips, face or tongue is a serious sign. Trouble breathing, wheezing or repeated coughing are also serious. Hives spreading over the body and repeated vomiting need urgent attention. Paleness, bluish skin, sudden floppiness or unusual sleepiness are important signs. Babies may also show sudden drooling and crying that cannot be soothed.

What to do right away

If you see any serious sign, call your local emergency number right away. Follow the advice the operator gives you. If your doctor has prescribed an emergency adrenaline auto-injector for your baby, use it right away as your plan says, then call emergency services. Lay your baby on their back. If they are vomiting or struggling to breathe, lay them on their side.

Take notes and share them

Write down which food you gave, when, and when the signs started. This record helps your doctor find the cause of the reaction. Do not give the food that caused the reaction until you talk to your doctor. But do not cut out a main food such as milk on your own. This can make it harder for your baby to get the nutrients they need.

This article does not replace a medical exam. Use any medicine only as your doctor advises. If you think your baby has a food allergy, talk to your child's doctor.