1 - Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, E.P.E., Rua Jacinta Marto, Lisboa, Portugal
2 - CEDOC, Integrated Pathophysiological Mechanisms Research Group, Nova Medical School, Campo dos Mártires da Pátria, 1150-190 Lisboa, Portugal
Divulgação: Reunião Internacional, apresentação sob a forma de póster em Food Allergy and Anaphylaxis Meeting, Copenhaga, Dinamarca, 18 a 20 de Outubro 2018
Introduction: Sesame seeds are a clinical relevant food allergen. However, its diagnosis can be challenging because skin-prick-tests (SPT) and Prick-Prick tests (PPT) with sesame seeds are often falsely negative. The use of PPT with Tahini (a paste of 100% roasted and ground sesame seeds) has been suggested as a potential option to evaluate sesame seed-induced allergy in the absence of positive skin tests. This fact seems to be explained by the presence of lipophilic allergens (oleosins) and/or a possible increment of the allergenicity of sesame proteins during the roasting process.
Clinical Case: We report a case of a healthy 29-year old female who was referred for a severe anaphylactic reaction - angioedema, cough, dyspnea, generalized urticaria and abdominal pain - after having a steak tartare with unknown sauce ingredients. She had previous episodes of scalp urticaria after eating bread with various types of seeds and also episodes of edema, dysphonia, dyspnea and palpitations after eating sesame bars. The patient tolerated other tree nuts and seeds and ate sesame seeds until 4 years ago without any reaction. We started the investigation by doing SPT with commercial extracts of sesame and other tree nuts, which tested negative. However, given the fact that the clinical history was very suggestive, avoidance of sesame seeds until further investigation was recommended and an emergency epinephrine autoinjector was prescribed. In the following appointment we performed PPT with sesame seeds that didn’t fulfill the criteria for a positive test (only erythema, no wheal), so we programmed to do an oral food challenge. Meanwhile the patient suffered a new episode of generalized urticaria and shortness of breath after eating Hummus (a chickpea paste containing Tahini).Given this episode, we performed PPT with Hummus and Tahini, which tested both positive. The patient eats regularly chickpeas, without symptoms. We assumed the diagnosis of sesame seed allergy and alerted the patient for the importance of fully avoidance of sesame seeds. Afterwards, she still had 2 mild reactions, one after eating sushi and another one after eating toasts, which she later on verified to contain sesame seeds.
Conclusions: Our report supports the potential role of PPT with Tahini as a diagnostic tool for sesame seed hypersensitivity when other tests like SPT and PPT with sesame seeds are negative.