Rash around the mouth after eating: irritation or allergy?

Two different things

A red mouth after dinner is one of the most common things parents notice once solids start. It’s usually one of two things:

• A contact reaction (irritation). Some foods irritate the skin they touch. NHS allergy dietitians say this is not an allergy and usually settles without any medicine.
• An allergic reaction. The immune system reacts to a food your baby has eaten. Hives or a red, itchy rash can be one of the signs (NHS).

Telling them apart changes what you do next, so it helps to know what each one looks like.

Contact irritation: what it looks like

NHS allergy dietitians in South West London describe a contact reaction like this:

• redness or a rash around the mouth, lips, chin and hands, or any skin the food touched, often between the mouth, chin and cheeks
• it doesn’t spread to parts of the body the food didn’t touch
• the redness starts to clear once you wipe the skin clean
• it isn’t itchy or swollen, and there are no hives
• your baby isn’t upset by it, and isn’t sleepy or floppy
• there are no other symptoms, such as wheezing or vomiting

It’s most common between 6 months and 3 years, when babies dribble and get food all over their face and hands while learning to feed themselves. Babies with eczema or dry skin are more likely to get it, and it can make facial eczema flare.

Foods that often cause it

The same NHS team lists:

• acidic fruit: citrus such as orange and lemon, pineapple, and berries such as strawberries and raspberries
• tomato, cooked or raw
• foods naturally rich in histamine, such as eggplant, spinach and salmon
• salty and spicy foods

The North West Allergy Network (NHS) adds that many other foods can do the same. The AAP’s symptom guide notes that some children get a rash where a food such as fresh fruit is rubbed on the skin, and some babies get hives around the mouth from drooling while eating a new food.

Signs that point to an allergy

An allergic reaction usually starts within minutes of eating a food, but can take up to 2 hours (NHS). Look for:

• raised, itchy welts (hives), or a red, itchy rash
• a rash that spreads beyond where the food touched
• mild puffiness of the face or around the eyes (lips, mouth or tongue that suddenly swell are an emergency: see “When it’s an emergency” below)
• red, itchy, watery eyes, sneezing or a runny nose
• vomiting, tummy pain or diarrhea
• coughing or wheezing

The NHS team says that if hives or a skin reaction spread to parts of the body the food didn’t touch, it’s not a simple contact reaction and you should see your doctor.

What to do for contact irritation

• Wipe it off. Gently wipe around the mouth with a wet cloth (North West Allergy Network). The redness should start to fade once the food is off the skin.
• Moisturize before meals. A barrier of emollient, ointment or petroleum jelly around the mouth and on the hands before eating keeps food off the skin (NHS South West London). ASCIA, the Australian allergy society, suggests a barrier cream with no perfume or food ingredients. Skip diaper (nappy) creams on the face: the NHS team says they dry the skin.
• Get more food in, less on. Offering the food on a spoon straight into the mouth, or mixed into a food that doesn’t cause redness, means less of it touches the skin (ASCIA, NHS South West London).
• Keep offering the food. The North West Allergy Network says the food doesn’t need to be removed from your baby’s diet. The South West London team suggests a short break of a few days, then a small portion, such as a teaspoon. Keeping a food in the diet matters: ASCIA says that keeping common allergy-causing foods in your baby’s diet can reduce the chance of allergy to them.

Never rub or smear food on your baby’s skin to “test” for an allergy. ASCIA says this doesn’t show whether your baby is allergic, because food can irritate skin anyway, and that skin contact without eating may even raise the risk of allergy to that food.

If you’re not sure

If you can’t tell which it is, treat it as a possible allergy. That’s especially true for a common allergen like egg, peanut, milk or sesame, or a food your baby is trying for the first time.

• Stop offering the food, stay with your baby and watch them closely for the next couple of hours.
• Take a photo of the rash and note what your baby ate and when.
• Call your pediatrician, GP or health visitor before you offer that food again. They can tell you whether to keep it in the diet, as you would with simple irritation, or whether your baby needs an allergy check.
• If signs show up in more than one part of the body at once, such as hives with vomiting, treat it as a severe reaction (below).
• If the lips, mouth or tongue suddenly swell, treat that as the emergency below, even if it’s the only sign.

See how to introduce allergens and food allergy vs intolerance. If your baby has eczema, see eczema and starting solids.

When it’s an emergency

Signs of a severe allergic reaction (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, drooling or trouble swallowing; turning pale or floppy, or very sleepy or unresponsive; or signs in more than one part of the body at once.

If 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.

Other rashes need help too. The NHS says to call 999 or go to A&E if a baby or young child has a rash that doesn’t fade when you press it, or has swollen lips, tongue or throat with difficulty swallowing. A red patch that keeps spreading and is painful to touch can be a skin infection (AAP), so see your doctor.

Where advice differs

• Hives only around the mouth. ASCIA (Australia) says a mild rash limited to the area around the mouth, including redness or contact hives, without any other allergy signs, is not usually an allergic reaction, and to offer the food again. The South West London NHS team describes a contact reaction as having no hives. This site takes the more cautious route: if you see hives, even only around the mouth, stop the food and call your doctor before offering it again.
• A break or not. The North West Allergy Network says the food doesn’t need to be removed. The South West London team suggests pausing for a few days. ASCIA says to offer it again. All three agree that simple irritation isn’t a reason to avoid a food long term.
• Who to call. In the US, call your pediatrician’s office.In the UK, call your GP or health visitor, or NHS 111 if you’re worried.Call your doctor or local health advice line.