Sesame is especially problematic as it falls outside of the “Top 8” allergens that must be disclosed as ingredients under the Food Allergy Labeling and Consumer Protection Act of 2004 (FALCPA). As such, food products containing sesame do not need to disclose that fact in the more straightforward ways other allergens must be disclosed.
The exact prevalence of sesame allergy in the US is unknown, and the diagnosis is challenging as there are no identified sesame-specific IgE or skin prick test thresholds that predict clinical reactivity.
In a study authored by Dr Kristin C Sokol et al and published this month in the Journal of Allergy and Clinical Immunology (JACI), 72 consecutive children with a mean age of 9.5 years and a known IgE-mediated food allergy were tested for sesame reactivity as well as reactivity to peanuts and tree nuts. For the purpose of the study, sesame allergy was defined as an immediate hypersensitivity to sesame at home or via clinic food challenge, and tolerance as the ability to ingest concentrated sesame (tahini) with no symptoms.
Of the 72 patients, 12 (16.6%) were found to be allergic to sesame while the remaining 60 were deemed tolerant.
Of the sesame allergic group, 9 of 12 (75%) were found to also be allergic to peanuts or a tree nut, compared to 26 (43%) in the sesame tolerant group.
The conclusion of the authors was that sesame allergy was common in this (small) cohort and often coincided with a peanut or tree nut allergy.
Further study will examine the age of sesame introduction into the diet, the ability of sesame allergic patients to tolerate seeds/oil, and the effect of eczema and elevated total IgE on modifying the utility of sesame IgE in predicting allergy.