Food allergies and intolerances in babies

Allergies to food are more common in children than in adults and some of the foods kids can be allergic to include milk, eggs, nuts and certain legumes (such as peanuts). In addition, sometimes some of the more common cereal grains – except rice and corn – can provoke allergy or intolerance in some children. An allergy to fish also usually appears in early childhood – unlike shellfish allergies, which more commonly develop in adulthood. It is fairly common to grow out of allergies to both milk and eggs in early childhood, but for kids who develop a peanut allergy early on (before starting school), this usually lingers into adulthood.

Is it possible to prevent allergies in kids?

There is never a guarantee that your baby won’t develop an allergy, but some research shows that introducing some of the most allergenic foods early on, like eggs and peanuts, can reduce the risk of a food allergy. This actually also applies to children with parents who have allergies. But the reasons behind why some children develop allergies and others don’t are very complex, and there’s a lot we still don’t know. Heredity plays a role and in addition to some foods, we also have allergenic substances in our environment, like dust mites, mould and pollen.

Food allergy and food intolerance are different things

One important thing to know is that a food intolerance (sensitivity to certain foods) and a food allergy are two different things. A food allergy is when a substance triggers the immune system and antibodies, and symptoms usually set in immediately – but they could also run a slower course with a delay of hours or days. If you are intolerant to a particular substance, on the other hand, it has nothing to do with your immune system. Rather, the sensitivity is because the body can’t break down (digest) the substance – such as lactose. Put simply, this means that with a sensitivity, the more you consume of the food to which you’re intolerant, the worse your symptoms will be. Meanwhile, in the worst case, an allergy can cause life-threatening symptoms even in very small quantities.

Food allergy symptoms in babies

If your child has a food allergy, a reaction usually appears within a few minutes – but it’s good to know that this won’t always occur the first time your child tastes something. That’s because we need previous contact with a food to develop antibodies and thus have a reaction. But if your child does have a reaction the first time they taste something new it’s likely because they had contact with the food in a way other than through ingestion, and the skin over activated the immune system.

A breastfeeding infant may have also come into contact with cow’s milk protein, for example, through mother’s milk, well before beginning to eat other food. Therefore, it is not uncommon for allergic reactions to occur the first time a baby drinks formula or at the introduction of solid foods. Food allergies in children may present in different ways, but usually show up on the skin as some kind of rash. However, allergies can also cause symptoms in the stomach/gut, in the mouth and on the lips, or respiratory symptoms.

Common food allergy symptoms:

• hives
• red rash
• eczema
• stomach pain, diarrhoea or constipation
• vomiting
• itchiness and irritation inside the mouth
• swelling of the lips and throat
• runny nose, nasal congestion or asthma.

If they aren’t severe, the symptoms usually subside on their own as long as you continue to avoid whatever caused the allergic reaction – but it’s important to determine the true cause and you shouldn’t start excluding different kinds of foods from your child’s diet on your own. If you suspect your child has an allergy, have it checked out by your healthcare provider.

Allergic shock – anaphylaxis

Many allergies are mild and can be handled relatively easily once you know your child has them. But occasionally, some people experience an acute reaction. When an allergic reaction is so strong that it becomes life-threatening, this is called allergic shock or anaphylaxis. Foods that can cause allergic shock include peanuts, eggs, nuts, shellfish, fish and milk. It is absolutely essential to seek emergency medical care if your child:

• has difficulty breathing
• is lethargic or not as responsive as usual
• develops severe swelling, redness or significant hives (urticaria) on their skin
• is severely itchy
• seems particularly impacted in some other way after eating – or if you are worried that something isn’t right.

Milk allergy is most common in babies

A cow’s milk allergy is the absolute most common allergy in infants. Luckily, they often grow out of it – usually by age three. But sometimes other allergies might pop up instead, for example to pollen or dust mites. When we become allergic, the immune system produces what are known as IgE antibodies, and in this type of milk allergy symptoms appear quickly, between 10 minutes and 2 hours after the child comes into contact with milk protein.

A common milk allergy symptom is a rash, such as hives, and if the baby has atopic eczema, this may be aggravated by a milk allergy. Other common milk allergy symptoms in babies include stomach problems (such as vomiting) or respiratory symptoms. The treatment is to feed your baby a diet with no milk protein – which isn’t always easy, so you’ll probably need the help of a paediatrician or dietician. In rare cases, milk allergy can produce allergic shock within fifteen minutes – in that case, immediately call your country’s emergency number.

An allergy to cow’s milk should not be confused with lactose intolerance, which is a sensitivity to milk sugar, or lactose. But lactose intolerance in babies is very unusual.

Gluten intolerance in babies

Gluten intolerance (Coeliac disease) is different from an allergy to certain cereal grains. In addition, sensitivity to gluten usually doesn’t appear immediately; it can take many years. In some cases, it won’t be evident until adulthood. Unfortunately, gluten intolerance is not something you grow out of – it is a lifelong condition, but the reactions may vary. Some people won’t notice anything if they happen to eat a little bit of gluten, while others may feel very ill from the same small amount.

Common symptoms in children with gluten intolerance are:

• losing weight or not gaining weight as they should
• not growing as expected
• poor appetite
• abundant, loose diarrhoea or constipation
• being tired and lethargic
• a swollen tummy, but slim arms and legs
• stomach pain.

Loads of tests for gluten and milk intolerance are sold online, but in addition to being expensive, it is unclear whether they are reliable. Determining whether your child is gluten intolerant isn’t something you can or should address yourself; you will need to get a diagnosis from a doctor. Many symptoms could be due to other causes, so it’s important to contact a doctor for a thorough investigation. If your child does turn out to be gluten intolerant, you will get support and help to handle it. In addition, do not try a gluten-free diet on your own to see if your child feels better – this could make it harder to investigate the problem once you do contact your healthcare provider.

Allergies to nuts and peanuts

Despite their names, peanuts and nuts are unrelated. A child with a peanut allergy may not be allergic to nuts, and vice versa. Children who develop allergies to nuts or peanuts by the time they start school often have to live with it into adulthood, because unlike milk and egg allergies, people do not usually grow out of these allergies.

A reaction to nuts or peanuts usually occurs within a few minutes of the child eating them. The most common reactions are mild, such as itching of the mouth, rash, and stomach problems. Occasionally, some children develop a severe nut allergy and in that case you need to seek emergency medical attention if your child eats nuts. It may be good to know that children who are allergic to pollen, such as birch pollen, can also react to nuts. This is called a cross-reaction and doesn’t usually produce symptoms as severe as a true nut allergy.

Please note that all information above is based on Swedish recommendations.