Food allergy and eczema
Question:
10/29/2020
I am curious as to how other allergists are managing evaluation of potential food allergy in infants/toddlers eczema. Although most patients with eczema don’t have food allergy some may. As eczema may be related to a non-IgE immunologic mechanism, some patients skin/immunocap test NEGative for IgE hypersenstivity to a food. A parent may still have a feeling that their toddler's eczema is worsened since introduction to a food ie milk etc. I am curious if other physicians who see such toddlers with negative skin/blood test and eczema are suggesting to such parents that they withdraw the food in question to see improvement in eczema or do they increase the food to see if eczema worsens? An in-office challenge won’t be beneficial for immediate hypersensitivty in this case if skin test negative but of course could bring about a delayed reaction.
Answer:
I am not aware of any significant studies that ask or answer the specific question posed - "... if other physicians who see such toddlers with negative skin/blood test and eczema are suggesting to such parents that they withdraw the food in question to see improvement in eczema or do they increase the food to see if eczema worsens?" If a ST and sIgE done to a food is negative then this would strongly suggest that IgE to that food is not present in the patient and, based upon this, does not need to be avoided. If the parents insist a particular food is etiologic then one could consider food avoidance.
I also asked Dr Ong to comment on this scenario:
Based on published data and clinical experience, the possibility of a food-induced non-IgE-mediated worsening of eczema is likely lower or rarer, as compared to a late eczema worsening from an immediate IgE-mediated food reaction. Due to the time involved in food challenge and follow-ups, many clinicians including myself would first evaluate the severity of the eczema in order to balance of risks and benefits of food elimination. If a child’s eczema is moderate to severe, in spite of standard eczema treatments, and parent is adamant that elimination of a certain food results in eczema improvement but reintroducing the food worsens it, then I would not take the complaint lightly. To prove it would still take a food challenge, controlling for other variables such skin treatments and other environmental triggers, and close follow-up for up to a week. More studies are needed in this area as there is no standardized test including atopy patch tests. I would refer you to the following articles for further reading on this interesting topic.
1. Campana R, Dzoro S, Mittermann I, Fedenko E, Elisyutina O, Khaitov M, Karaulov A, Valenta R. Molecular aspects of allergens in atopic dermatitis. Curr Opin Allergy Clin Immunol. 2017 Aug;17(4):269-277. doi: 10.1097/ACI.0000000000000378. PMID: 28622169; PMCID: PMC6392175.
2. Wassmann-Otto A, Heratizadeh A, Wichmann K, Werfel T. Birch pollen-related foods can cause late eczematous reactions in patients with atopic dermatitis. Allergy. 2018 Oct;73(10):2046-2054. doi: 10.1111/all.13454. Epub 2018 Oct 2. PMID: 29654628.
Dr. Peck Ong
I hope this has been helpful.
Andrew Murphy, MD, FAAAAI