Rising Concerns over Multiple Food Allergies
Food allergy is considered one of the most significant public health issues of the 21st century. Among common allergens, tree nuts such as hazelnuts, walnuts, cashews, and pistachios account for the majority of severe allergic reactions. Hazelnuts, in particular, are among the most common allergens in children and adolescents.
Doctors increasingly use oral immunotherapy (OIT) to reduce sensitivity to these allergens. But does treating hazelnut allergy help reduce sensitivity to other tree nuts as well?
1. Rise in Multiple Allergies
Many children are allergic to more than one type of tree nut.
2. Importance of Informed Treatment Decisions
Physicians need to understand which therapies provide cross-protection and which do not.
3. Managing Daily Life Risks
Families need clear information about the level of safety provided to their allergic child.
Key Findings from a Healio Study
In a recent study published by a team of researchers in Healio, it was revealed that oral immunotherapy for hazelnut allergy only affects sensitivity to hazelnuts, and does not reduce immune response to other tree nuts such as walnuts or cashews.
This finding contradicts some earlier studies suggesting that treating walnut allergy might also reduce hazelnut sensitivity. In fact, the researchers concluded that oral immunotherapy does not consistently offer cross-protection among all types of tree nuts.
A Closer Look at Oral Immunotherapy (OIT)
OIT involves gradually administering controlled doses of the allergen to the allergic individual. The goal is to train the immune system to tolerate the allergen and reduce the severity of allergic reactions in case of accidental exposure.
In this study, patients received increasing doses of hazelnut protein. By the end of the treatment, 96.7% of participants could tolerate up to 4,000 mg of hazelnut protein. However, their tolerance to walnut and cashew remained unchanged.
Why Does This Matter?
The Difference Between Allergy and Cross-Reactivity
Why don’t similar tree nuts provide mutual therapeutic benefit?
Although hazelnuts, walnuts, and cashews share some structural protein similarities, the immune system recognizes and responds to their proteins differently. The allergenic proteins differ significantly in their structure.
Cross-Reactivity Among Tree Nuts
Walnut ↔ Hazelnut: Significant cross-reactivity
Cashew ↔ Pistachio: High cross-reactivity
Walnut ↔ Cashew: Low or no cross-reactivity
Thus, treating a walnut allergy may help with hazelnut, but the reverse is not true. This was clearly confirmed by the Healio study.
Expert Recommendations Based on New Findings
Dr. Arnon Elizur, a pediatric allergy specialist involved in the study, recommends:
“For patients with multiple tree nut allergies, it's best to start OIT with the nut that provides the broadest cross-protection. In this case, walnut is a better starting point than hazelnut.”
Hazelnut OIT: Benefits, Limitations, and Risks
Benefits:
Reduced severity of allergic reactions upon accidental exposure
Improved quality of life
Ability to consume foods with cross-contamination risk
Limitations:
Effective only for the specific allergen
Requires long-term monitoring
No effect on concurrent allergies
Risks:
Possible anaphylaxis during treatment
Requires daily and consistent intake
Must be administered in a medically supervised environment
The Future of Allergy Treatments: A Need for Combined Therapies?
This study suggests that for people with multiple allergies, combined immunotherapy may be necessary—treatments tailored to two or more allergens simultaneously.
Current research is exploring multi-allergen formulations to induce broader immune tolerance.
The Role of Parents in Treatment
For children undergoing immunotherapy, parents play a critical role:
Ensuring accurate dosage
Reporting side effects
Attending regular follow-ups
Being prepared with an epinephrine auto-injector (EpiPen)
Key Takeaways for Paknamad Users
If your child is allergic to hazelnuts, treatment is only effective for hazelnuts.
Treating walnut or cashew allergies won’t automatically provide hazelnut tolerance, and vice versa.
Always consult an allergy specialist before starting any treatment.
Conclusion
The recent study published in Healio makes it clear that oral immunotherapy for hazelnuts does not reduce sensitivity to other tree nuts. These findings pave the way for more precise and effective treatment planning for both doctors and patients.
In an era of rising food allergies, understanding such scientific insights is crucial—for families, healthcare professionals, and even health policy-makers.
Source: Healio
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