Protein Allergy in Infants and Children: What It Is and How It Manifests

Food allergy is an abnormal immune reaction to food: the immune system mistakenly identifies food proteins as dangerous. In children, it is most often caused by chicken eggs and cow's milk, although any food can trigger a reaction. Below is a calm breakdown of what it is and how it manifests in infants and older children.

What protein allergy is and which proteins cause it

When immunoglobulin E (IgE) binds to food molecules, inflammatory substances such as histamine are released and symptoms appear. Among the most common allergens are cow's milk, eggs, wheat, soy, peanuts, nuts, fish and seafood. In Europe this list also includes sesame, lupin, celery, mustard and sulfites. The set depends on what people eat in a given country: in China and Japan it is seafood, wheat and soy, in Israel sesame, in the US and Europe peanuts.

Why protein allergy occurs in infants and newborns

The exact causes are not fully understood. Risk factors include heredity: the chance is higher if close relatives have allergy, asthma or eczema. Vitamin D deficiency, obesity, excessive cleanliness, and living in a city with a more sterile environment and polluted air also play a role. In atopic dermatitis, allergens can penetrate through dry damaged skin. Allergy is more often diagnosed in boys. The real prevalence of food allergy is about 6% in children and 1.5–2% in adults.

Symptoms of protein allergy in children: skin, digestion, breathing

Symptoms usually begin within 2 hours after eating, sometimes later. Key signs are hives, a hoarse voice and wheezing. The picture may further include:

• itchy skin or raised rash, swelling of the lips, face and eyes;
• cough, wheezing or noisy breathing, nasal congestion, runny nose;
• nausea, vomiting, abdominal pain, diarrhea;
• dizziness, a pre-fainting state, a sense of impending doom.

In young children the manifestations are the same as described above (skin, breathing, digestion), so if a reaction is suspected the child should be examined by a doctor.

How protein allergy differs from intolerance

Food intolerance is also a reaction to food, but without involvement of the immune system. It more often causes bloating, cramps, abdominal pain or diarrhea, usually several hours after eating. True allergy is much less common than intolerance, and it is true allergy that can involve dangerous reactions.

How protein allergy is diagnosed in a child

The diagnosis is based on medical history, a food and symptom diary, skin tests and blood tests for food antibodies. Sometimes an elimination diet is used: the food is removed until symptoms disappear, then reintroduced under supervision. Food challenge tests are performed only under the supervision of a trained specialist — you must not trigger a reaction on your own, especially if the first one was severe.

When to see a doctor

If you suspect an allergy in yourself or your child, see a doctor, and if the allergy is confirmed, see an allergist. Do not remove foods from the diet without talking to a doctor. A severe reaction can develop immediately or within two hours after eating.

An allergic rash alone is not a reason to call an ambulance; 103 or 112 — if the lips, mouth, throat or tongue suddenly swell, breathing becomes very fast or difficult, the throat tightens and swallowing is hard, the skin, tongue or lips turn blue, gray or pale, the child suddenly becomes lethargic, limp and does not respond as usual, severe drowsiness or confusion appears, the person faints and does not wake up.

This material is for reference: it helps you learn what protein allergy looks like, but does not replace a doctor's consultation — the final conclusions and examinations remain with the specialist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer