Food allergies
What are food allergies?
Food allergies are the immune system’s reactions to certain components present in food, especially proteins. In allergic people, the immune system identifies harmless substances as being dangerous, causing an exaggerated response that can affect different organs and systems.
Although they can occur at any age, they are more common in children and, in many cases, disappear over time. However, some allergies may persist or even develop in adulthood.
Which foods cause the most allergies?
Any food can cause an allergic reaction, but the most common foods are as follows:
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In children: cow's milk, egg, nuts, fish, pulses.
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In adults: shellfish, fresh fruits (especially Rosaceae), nuts, fish, molluscs and certain additives.
The 14 notifiable allergens in Europe are: milk, egg, fish, crustaceans, molluscs, gluten, soybeans, celery, mustard, sesame, nuts, peanuts, lupin and sulphites.
How does the body respond to a food allergy?
When an allergic person ingests, inhales or even comes into contact with a food to which they are sensitive, their immune system produces antibodies (IgE) that trigger an inflammatory response. This reaction can be mild and localised or severe and generalised, depending on the individual and the amount of allergen.
Most common symptoms
Allergic food reactions may occur within minutes or up to 2 hours after exposure. Symptoms vary by person and degree of sensitivity:
Mild or moderate symptoms:
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Itchy lips, mouth, or throat.
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Urticaria, welts or redness of the skin.
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Abdominal pain, nausea, vomiting or diarrhoea.
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Nasal congestion, sneezing or a mild cough.
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General discomfort.
Severe symptoms (anaphylaxis):
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Shortness of breath, chest tightness, or wheezing.
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Swelling of the lips, tongue, eyelids or throat (angioedema).
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Dizziness, hypotension or loss of consciousness.
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A severe, life-threatening, multisystem reaction.
Food-induced anaphylaxis requires urgent medical attention and the administration of intramuscular adrenaline.
How are they diagnosed?
A food allergy must be diagnosed by an allergist, since an allergy is not the same as food intolerance. The following tests that can be used:
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Detailed medical history and food diary.
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Prick test or skin test with food extracts.
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Specific IgE blood test.
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Controlled oral challenge tests in a hospital setting.
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In some cases, elimination and reintroduction testing.
Food allergy treatment and management
There is currently no permanent cure for most food allergies, so treatment is based on prevention and managing reactions. The recommended strategies are:
1. Strict food avoidance
Reading labels, avoiding traces, asking in restaurants and maintaining a controlled diet are key to avoiding reactions.
2. Personalised action plan
The allergist will provide clear instructions on how to act in the event of accidental exposure.
3. Use of rescue medication
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Antihistamines for mild reactions.
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Self-injectable adrenaline for people at risk of anaphylaxis.
4. Educating the people around the patient
Informing family members, caregivers, schools and workplaces about the allergy and how to act in an emergency.
Practical everyday tips
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Always carry emergency medication with you if you are at risk of a severe reaction.
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Wear wristbands or carry ID cards for your allergy.
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Cook at home when possible and avoid cross-contamination.
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Be extra cautious at events, buffets, or meals prepared away from home.
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When in doubt: avoid eating the food.
