While checking out what [someone said about soy sauce in a comment in another post](https://www.reddit.com/r/japanlife/comments/x13xkb/soy_sauce_and_allergic_skin_reaction/?utm_source=share&utm_medium=ios_app&utm_name=iossmf) about about allergies. I came across this paper. I had no idea that this was a thing.
> I describe the difficulties of diagnosing soy sauce allergies, since soy sauce produces histamine during brewing and storing. Some Japanese people develop irritation, itching and cellulitis after consuming foods with soy sauce. These symptoms could be caused by soy sauce allergy, histamine poisoning and/or other factors.
> My diagnostic criteria were suitable to evaluate soy sauce allergies using skin tests by decreasing the number of false-positive reactions. Soy sauce typically contains histamine since it can cause various symptoms including histamine poisoning, urticaria [hives] and flushing. These histamines are made during the brewing process because shoyu-flavones inhibit histidine decarboxylase. It is interesting to note that our patients did not appear any symptoms after eating histamine-containing foods (e.g. beer, wine and tuna) or histamine-releasing foods (e.g. additives, strawberries, tomatoes and peanuts).
[Soy Sauce and Allergic Skin Reaction](https://clinmedjournals.org/articles/ijam/ijam-1-004e.pdf)
2 comments
Most Japanese people don’t know that this is a thing unless they are directly affected
I have it and it makes eating out here basically impossible.