Thank you for your recent inquiry.
Dr. Dana Wallace recently reviewed the literature on this subject related to a recent presentation. I am therefore asking Dr. Wallace to share her thoughts with us regarding your questions.
As soon as I receive a response from Dr. Wallace, I will send it to you.
Thank you again for your inquiry.
Sincerely,
Phil Lieberman, M.D.
We have received the response from Dr. Dana Wallace. Thank you again for your inquiry and we hope this response is helpful to you.
Sincerely,
Phil Lieberman, M.D.
Response from Dr. Dana Wallace:
Unfortunately, as your astute questions suggest, there is more that we DO NOT know about Pollen Food Allergy Syndrome than what we DO know. The preferred term Pollen Food Allergy Syndrome (replacing Oral Allergy Syndrome) emphasizes that while symptoms are usually limited to the oropharyngeal area, systemic symptoms can occur in 2-10 % of patients. Peach, peanut, tree nuts, and mustard are high-risk foods for progressing to systemic symptoms when they have originally been described to produce only oropharyngeal symptoms. But, unfortunately we cannot always predict exactly which foods can progress to systemic reactions. It becomes even more complicated when we take into account that ripeness, varietal differences, and changes induced by storage can affect the degree to which a patient can react to these foods, especially the fruits and vegetables.
While the symptoms are usually associated only with raw foods, cooked plant foods may provoke symptoms. When this occurs, higher risk is present and the patient should be advised to avoid the food in all forms. For the same reason, a positive prick test using commercial extracts may indicate a higher level of sensitivity than when only the prick-prick testing using the fresh fruit or vegetable is positive.
As for this 16-year-old patient, we will address each food at a time. As for peanuts, although the sIgE is elevated, the patient is eating this food and not having any reaction. I would thus allow her to continue to eat peanut butter. I would think that she could eat peanuts in any form but I am not say this for sure. Thus, if she has not been eating fresh or roasted peanuts and desires to do so, I would likely do an in-office challenge as I am not aware of any studies that absolutely guarantee that peanut butter has not undergone some allergen modification or degradation with processing while the raw or roasted peanut allergens remain unaltered.
As almonds fall into one of the higher risk categories described above and one could never be sure just how much "roasting" the almonds have undergone, I would likely ask the patient to avoid eating almonds in any form.
Nutella, which has hazelnuts as the main ingredient, seems to be tolerated. Although we know that all tree nuts MAY cross-react, this is not always the case in all individuals. Given the markedly elevated sIgE, I would suggest an in-office challenge to hazelnuts if she does not currently ingest them separate from Nutella. As for other tree nuts, I would suggest prick-prick skin testing to these individual nuts (using crushed up nuts) and if positive conduct an in-office challenge (preferably to the raw nut) to any other nut that she plans to ingest, if they are not currently in her diet. If any symptoms, including oropharyngeal, develop during the oral challenge, I would ask that she avoid this nut in all forms.
If you want to build in the most safety and avoid testing and challenges, the development of ANY symptom to a tree nut, including oral symptoms, is a reasonable basis on which to ask the patient to avoid ALL tree nuts.
I do not think that we can rely upon the level of sIgE to predict which foods will cause mild or severe PFAS symptoms. We just don't have the research to do so. Unfortunately, even oral challenges to foods are not 100% accurate, e.g., 33% accurate for melon and 80% accurate for foods falling into the Rosaceae family (peach, plum, almond, apple), depending upon the allergen and time of year when challenged.
For foods not considered high-risk for evolving into systemic symptoms, if the symptoms are only oropharyngeal and only to the non-cooked forms of the food, I would allow the patient to continue to ingest the cooked foods, emphasizing "well-cooked". The level of sIgE or prick skin testing would not alter these recommendations.
Given the uncertainly of when a systemic reaction may occur to a food that previously caused only oropharyngeal symptoms, it is my practice and recommendation to prescribe two epinephrine auto-injections to all of these patients.
In summary for the Pollen Food Allergy Syndrome:
1) In most instances the course is benign
2) A small percent may experience a serious event
3) Severity of subsequent reactions is often unpredictable
4) Allergists are divided on management strategy
5) NIAID guidelines as broadly interpreted would allow for administration of auto-injector