Nut allergy

Frequent food allergy, usually not defined in terms of calories, which refers to nuts, seeds and kernels (see below) and requires subtle clinical clarification. The anamnesis and skin tests are the most important factors in establishing a diagnosis. In addition, the detection of specific IgE antibodies in serum is required. The test method with the greatest predictive power is the very complex, ultimately often indispensable, double-blind placebo-controlled oral provocation test.

Nut allergies, like all other food allergies, can also be divided into 3 subgroups (type A-C):

• Type A: occurs mainly in small children who are sensitised via the gastrointestinal tract. After months or years, a tolerance to these foods often develops.
• Type B (older children and adults): Primarily sensitized to air (e.g. to pollen), food allergies may occur due to a cross-allergy (structural similarity of the allergens). This sensitization pathway is mostly found in allergies to nuts, seeds and kernels.
• Type C: occurs mainly in non-atopic women. Sensitization is via the gastrointestinal tract. These allergies are often present for life.

In an English collective, a STAT6 3'UTR polymorphism has been shown to be associated with susceptibility and severity in patients with nut allergy in our population (Amoli MM et al. 2002).

Reactions to the storage proteins and PF10 proteins or profilins must be distinguished.

Storage proteins are common allergens, especially in children: Severe symptoms with life-threatening anaphylaxis possible in primary sensitization to prtoein components of the nut. These proteins are possibly heat-stable, i.e. even after heating the symptoms develop, often traces of the allergen are sufficient to trigger the symptoms.

PR10 proteins and profilins, common allergens in adults, show milder symptoms such as oral allergy syndrome, often triggered by cross-allergies with pollen. These proteins are usually heat labile, i.e. they are no longer allergenic after heating. Traces do not have a corresponding effect.

Avoidance of the triggering allergen, prescription of emergency kit, if necessary therapy s, under anaphylactic shock.

For peanut allergy, oral hyposensitization with Palforzia has been approved since December 2020, from the age of 4!

The strict elimination of allergy-causing foods is the most important prevention. This is often difficult, as food is often insufficiently declared.

1. Amoli MM et al. (2002) Polymorphism in the STAT6 gene encodes risk for nut allergy. Genes Immun 3:220-224.

2. Senti G et al. (2000) Nuts, seeds and kernels from an allergological point of view. Schweiz Med Wochenschr 130: 1795-1804.
3. Schneider S (2022) Nut allergy is not equal to nut allergy clinic, diagnosis and therapy. Dermatologist 73:399