An emerging food allergy over the last few decades in the UK.

Sometimes isolated, but 25% of peanut allergic are also sesame allergic.

Black, white, red varieties are found – in allergy terms identical.

Other co-sensitivities are pine nut (!), brazil nut and macadamia [Helen Brough, JACI 2020].

Sesame often used in bakery products, also in Far Eastern (gomashio, furikake are sprinkled over Japanese food) and Middle eastern food. Typical white seeds are obvious (and stick to everything, which makes cross contamination a big problem) but black sesame seeds found in Japanese cooking, and tahini (sesame paste, used in hummus and dressings), are not recognisably sesame seeds at all.

Sesame oil is generally unrefined, which is to say that it is likely to contain significant amounts of sesame protein and therefore trigger reactions. With many other kinds of oil, this isn’t the case because they are refined and lack proteins.

Evidence exists that ingested whole seeds can pass through digestive tract of allergic person without causing a reaction – which can confuse diagnosis and/or suggest tolerance when it isn’t. Or delayed rupture of seed case may cause delayed but severe reactions (90 mins plus after ingestion)

Some sesame allergic appear to be sensitized to oleosins, which are not water soluble so are not found in standard skin prick and IgE test solutions, potentially giving a false negative result. In 2020 study from Israel, SPT only 33% sensitive, cf 86% (although specificity also drops to 50%). So recommended that you test with both commercial solution and shop bought tahini – if never eaten/reacted, they recommend avoiding, especially if eczema and/or other food allergies.