Effect of an Immune-supportive Diet on Gut Permeability and Allergic Symptoms in Children With Peanut and/or Nut Allergy

The incidence of allergic asthma, atopic dermatitis and food allergy started to grow to epidemic proportions after the 1960s. Peanut and nut allergy are common food allergies. Peanut allergy affects 1.4 to 3.0% of the children. Peanut and nut allergy are often lifelong and may be severe. Peanut allergy is the leading cause of (fatal) food anaphylaxis. Once peanut and nut allergy have developed, there is currently no cure other than adhering to an avoidance diet and carrying and using intramuscular epinephrine or oral antihistamines in the case of accidental ingestion. Oral immunotherapy with peanut or nuts is only applied in research setting, however, it has several drawbacks and is still in its infancy.

Inter- and intra-individual differences in threshold in peanut allergy:

Threshold levels for peanut and nuts, the lowest amount of peanut or nuts causing a reaction, may largely vary between allergic children, for which there is no clear explanation. Thresholds can be determined during oral food challenge tests with peanut or nuts in the hospital. An international multi-center study found that 5% of the children react to a low threshold of 1.7 mg of peanut protein during the food challenge in the hospital, 7.4 mg of cashew nut protein and 0.29 mg of hazelnut protein during a food challenge in the hospital. These are only traces, while 50% react to 67 mg of peanut protein. This is around 1⁄3 of a peanut, thus also a small amount. These threshold levels demonstrate how careful patients have to be in their dietary behavior. Patients with a low threshold are very sensitive to peanut or nuts and are at greater risk to react to traces of allergenic protein which can be intentionally or unintentionally present in prepacked or unpacked food. Studies have shown that the lower the threshold, the greater the impact on the health-related quality of life of the child and their parents. It is poorly understood how these differences in sensitivity (threshold levels) between individuals can be explained. Sensitization to peanut or nuts, as demonstrated by levels specific immunoglobulin E (IgE) for peanut by blood testing or the size of the skin prick test with peanut or nuts cannot explain the difference in threshold level, because they have a low predictive value for the threshold. Infection diseases illness, exercise and sleep deprivation significantly reduce the threshold level in allergic adults. However, these co-factors are not relevant in all patients, specifically not in children, and cannot explain the large differences in threshold levels observed.

Peanut and nut allergy coincides with other atopic disease:

Peanut and nut allergic children frequently suffer from other food allergies, such as milk and egg, and other coexisting atopic (allergic) diseases such as atopic dermatitis, allergic rhinitis (hay fever) and allergic asthma, leading to a substantial allergic burden in children with peanut and nut allergy. Because of the burden of these allergic conditions, the quality of life of children with food allergy is decreased, however underestimated. and even lower compared to chronic diseases, e.g. lower than children with diabetes. All these coexisting allergic diseases are based on immunologic and chronic inflammatory processes. Asthma is a systemic inflammatory disorder with a close link between the upper and the lower airways. The majority of patients with asthma have concomitant rhinosinusitis. The respiratory system is also under the influence by co-morbid conditions related to the gastrointestinal tract (food sensitization, bowel inflammation), the skin (eczema, barrier dysfunction) as well as the nervous system (neuroimmunologic network, cognitive dysfunction).