Sesame allergies: clinical significance, diagnosis, and therapy

Abstract

Sesame (Sesameum indicum) belongs to the pedalium family (Pedaliaceae) and is used primarily in the preparation of food, especially in oriental and Asian cuisine. As a so-called emerging allergen, it is becoming increasingly relevant in the everyday routine of physicians active in the field of allergology in the wake of the globalization of dietary habits and the general trend towards vegetarian and vegan lifestyles. Due to the increased occurrence of anaphylactic reactions to sesame, the European Union has included sesame in the list of food allergens requiring labeling. In addition to its use in private and industrial food preparation, sesame is also utilized in the cosmetics and pharmaceutical industries. This paper is an overview of selected scientific articles and is based on research in PubMed and specialist databases. Immediate-type IgE-mediated reactions (type I according to Coombs and Gell), as well as delayed-type contact allergic reactions (type IV according to Coombs and Gell), to products containing sesame and sesame oil have been described. The clinical spectrum is broad and ranges from contact urticaria and dermatitis to fatal anaphylaxis. Important allergens in immediate-type allergy include albumins, vicilins, oleosins, and globulins; relevant contact allergens include sesamolin, sesamin, and sesamol. The diagnostic work-up for suspected sesame allergy includes skin tests, which should preferentially be carried out with native allergens due to their higher sensitivity and specificity, as well as determination of sesame-specific IgE antibodies. However, lipophilic oleosins in particular are underrepresented in analytical methods. Differentiated, component-based IgE diagnostic testing is desirable. Oral provocation is the gold standard, whereby it is important to ensure low and safe initial doses as well as adequate maximum doses. Beside diagnostic measurements including skin tests, detection of IgE antibodies and oral provocation tests, the education of patients with sesame allergy is of particular importance. This serves, firstly, to prevent recurrence of allergen exposure and, secondly, should contain information on self-management in the case of repeated reactions. The value of oral tolerance induction and preventive measures such as early introduction as a dietary supplement remains to be clarified in the future.