Peanut and nut allergy

In a food allergy, the immune system makes antibodies against proteins that occur in the diet. These are very ‘normal’ proteins, which most people can tolerate. However, the body of an allergic person sees that ‘normal protein’ as an invader and therefore produces an antibody (IgE). This also releases the substance histamine; the substance responsible for the symptoms of an allergy.

Allergens

Proteins that can trigger allergic reactions are called allergens. Certain proteins in nuts and peanuts are therefore allergens. Sometimes only a very small amount of an allergen is needed to trigger an allergic reaction.

Anyone with a nut allergy is not automatically allergic to peanuts. Strictly speaking, peanuts are not nuts, but legumes. However, these two allergies often occur together.

How often does it occur?

About 3 in 100 people in the Western world have a peanut allergy. Nut allergy is somewhat rarer: it occurs in 0.4-1.4 percent of the adult world population.

Heredity plays a major role in the development of allergic reactions. If both parents have an allergy, a child has an 80 percent chance of developing an allergy as well.

Symptoms

A very small crumb of nut or peanut can cause serious complaints in someone who is allergic to it. For some foods, such as peanuts, inhaling the smell is sometimes enough to provoke a reaction.

The most common reactions after eating peanuts and tree nuts are:

• Skin complaints: hives, hives, atopic eczema and fluid accumulation under the skin.
• Angioedema: fluid retention, especially locally on the face. Angioedema occurs especially under the eyes, on the lips and in the cheeks. If angioedema in the throat occurs, breathing can be blocked with all its consequences.
• Respiratory complaints: coughing, tickling cough, sneezing, wheezing, shortness of breath, mucus and asthma.
• Anaphylaxis: severe reaction that can eventually lead to shock. Of all foods, peanut is the most likely to cause anaphylaxis.

Diagnose

Doctors do a blood test or skin prick test. However, these tests do not provide 100 percent clarity.

A food challenge test is actually the gold standard for detecting a food allergy. In doing so, you first make sure that you do not ingest any nuts and/or peanuts at all (elimination). When the symptoms diminish or disappear, you eat a tiny bit of the allergen again (the provocation). If the complaints then return, an allergy has been demonstrated. Such a food challenge test should always be performed under the supervision of an expert. In this way, it can intervene in time and accurately if there are serious allergic reactions.

Peanut and/or nut-free food

If the diagnosis is peanut and/or nut allergy, you can take measures. There is no cure for a peanut or nut allergy. You can grow out of it.

The best way to prevent complaints is to avoid foods with nuts. That’s relatively easy when it comes to eating peanuts and tree nuts as a snack. It becomes more difficult when nuts and peanuts are processed in products such as almond paste, marzipan, breakfast cereals, cookies, bonbons, sauces, stocks, pesto and marinades. And even peanut-derived ingredients can be found in products like lotion, shampoo, detergent and cosmetics.

Cross-contamination can occur in a factory when a food (without peanuts or nuts) is processed near a product that does contain peanuts or nuts. For example, “traces” (very small amounts) of nuts can get into the food if the machine has not been cleaned properly. Nowadays, the packaging must state whether a product is peanut or nut-free or whether the product was made in a company that also processes nuts and peanuts.

In case of emergency

In anaphylactic shock it is important that epinephrine is administered as soon as possible. This adrenaline is injected (by a bystander) with an adrenaline pen. This causes the blood vessels to narrow again, making the injection life-saving.