How do we know when peanut and tree nut allergy have resolved, and how do we keep it resolved?

Abstract

Over the last two decades, the prevalence of peanut and tree nut allergy has increased throughout the western world. Adverse reactions to these foods account for over 50% of all deaths resulting from food-related anaphylaxis. Until recently, evidence suggested that all peanut and tree nut allergy were permanent. It is now known that about 20% and 10%, respectively, of young patients outgrow peanut and tree nut allergies. Achieving tolerance is associated with increasing circulating T regulatory cells and reduced production of allergen-specific IgE. Reliable predictors of resolution are not yet available. A direct correlation between skin test weal size and allergen-specific IgE, at the time of diagnosis and likelihood of resolution, has been reported. Resolution of peanut or tree nut allergy cannot be determined conclusively by either allergen-specific IgE analysis or by skin prick testing. Oral food challenge is the gold standard for determining resolution of food allergy. Food challenges should only be undertaken in a clinical setting fully equipped to deal with a potential severe adverse reaction. Approximately 8% of patients who outgrow peanut allergy may suffer a recurrence, but recurrent tree nut allergy has not been reported to date. Infrequent ingestion of peanut may be related to the re-emergence of allergy. Induction of tolerance through oral immunotherapy or sublingual immunotherapy is now being actively studied, but remains experimental. Studies have reported short-term desensitization to peanut, but ongoing follow-up will determine whether tolerance is achieved long term.

Extended boiling of peanut progressively reduces IgE allergenicity while retaining T cell reactivity

“…Peanut allergy tends to be persistent [8] with a 10-year remission rate of less than 20% [9]. Avoidance of peanuts cannot be guaranteed and accidental ingestion may be dangerous or even fatal [10].…”

Sensitization patterns of cow’s milk and major components in young children with atopic dermatitis

“…Several studies have shown a correlation between the concentration of allergen-specific IgE and the probability of clinical reactivity [15, 16]. Lower IgE levels are associated with earlier resolution of food allergy, and the rate of the decrease of serum IgE levels can be a predictor of when challenges are appropriate [21, 22]. However, without a history of a suspected allergic reaction, a "diagnostic" point alone cannot be used to diagnose a definite food allergy.…”

Thermal and Nonthermal Methods for Food Allergen Control

“…Using SPT to test for allergies is not considered quantitative and is used only to determine the presence or absence of an allergy. However, this test is not always an infallible method for determining allergy, for patients with atopic dermatitis may develop false-positive wheals [12]. Subjects must also abstain from using drugs, such as antihistamines, that will affect the results of the test.…”

“…In this type of study, the subjects are required to consume foods that may potentially cause an allergic reaction. This can prove dangerous, since patients must be directly subjected to allergens, and those who are susceptible to anaphylaxis should not be included in this type of study [12]. Perry et al [88] tested the safety of OFC studies and found that 28% of OFC participants had severe reactions.…”