Sesame Allergy – To Challenge or not to Challenge that is the Question

Background: Sesame is the third most common food allergen in Israel, and a major cause of fatal allergic reactions. Oral food challenge with sesame is frequently avoided as this allergy is considered persistent and challenges withhold high-risk of anaphylaxis.

Methods: Children with a history of an immediate allergic reaction to sesame were included in this study. All children underwent skin prick test (SPT) and a gradual open food challenge (OFC) with sesame regardless of SPT results. Children who completed the OFC, and ate 4 grams of sesame protein with no-allergic reaction were defined as tolerant. Children with allergic reactions during OFC were defined as OFC failure.

Results: 102 children with a history of sesame allergy, 44(43%) girls and 58(57%) boys, ages 6 months to 17 years of age, were evaluated. Following OFC 55(54%) were tolerant and 47(46%) were allergic to sesame. SPT size to natural sesame paste and commercial reagent correlated with the risk of OFC failure (p<0.001). Notably, 13/47 children who exhibited allergy to natural sesame protein underwent OFC with backed sesame food of which 11/13 (85%) were tolerant to backed sesame.

Conclusion: Open food challenge, although encompass the risk of anaphylaxis, is essential for the diagnosis of sesame allergy as unexpectedly 47% of children with a suggestive history and a positive SPT could tolerate 4 gram of sesame natural protein. SPT size to sesame could predict OFC outcome. Interestingly 85% of sesame allergic children could tolerated backed sesame. Further studies are required for evaluating the role of backed sesame for oral immunotherapy of this protein.