Yuzu is a citrus fruit in the Rutaceae family, which includes lemons, limes, oranges and grapefruit.
It used to be primarily associated with Japanese cuisine, but it is now being used more as an ingredient in everyday items.
There have been case studies of anaphylaxis from eating yuzu. The link has not yet been established, but could either be linked to pectin, which yuzu contains a lot of or due to the seeds in yuzu, which contain 2S Seed Storage Proteins, which are usually associated with seed and nut allergies.
Like lemons, yuzu contains limonene, which is a component of the oils found in the peel of certain fruits. Limonene is a well known skin irritant, so it may cause sufferers to react to the skin while being able to eat or drink the fruit.
Like other citrus fruits, yuzu contains furanocoumarins (but to a lesser extent than other fruits). These chemicals can get on the skin and in combination with ultraviolet light (sunlight), they can cause a sunburn-like rash. Furanocoumarins are found in higher concentrations in fresh herbs and are natural irritants which can cause allergic contact dermatitis. This is more common in occupations where you are frequently come into contact with food, like chefs, cooks, growers and pickers.
I have put together some more comprehensive resources at https://www.allergyresources.co.uk/Yuzu.php
The allergy resources page for yuzu covers the types of jewellery that contain it, which allergic syndromes are linked to this allergy and other metals that are commonly cross-reactive with yuzu.
There are also regularly updated links to useful websites specifically for yuzu allergies and the latest research papers on the topic.
If you have multiple allergies and are interested in how they are linked or want to find out more about food allergies outside the usual top 14 then you can follow me on Facebook or Twitter, where I share a food allergy card every day of the week.
JeLuDa Allergy 