Food allergies are gaining more visibility than ever before. But unless you're from Japan, you've likely never had to think about whether or not you're allergic to buckwheat (the seeds used to make soba noodles). In an effort to raise awareness of the allergy, a group of soba restaurants near Sapporo on the island of Hokkaido distributed temporary tattoos created to detect allergic reactions, Spoon & Tamago reports.

The tattoos, which were designed by the ad agency J. Walter Thompson with help from a dermatologist, were inspired by traditional Japanese art styles. To apply them, wearers used the warm broth left over from boiling soba noodles instead of regular water. If they had a reaction, the skin beneath the tattoo would turn red and add elements to the design. 

Buckwheat is one of the most common allergens among children in Japan, and if the ingredient became more popular in other parts of the world you might see more cases being reported. Symptoms range from gastrointestinal distress to anaphylaxis, which can cause the throat to swell. Two hundred of the allergy-detecting tattoos were passed out at an event last month, and now Hokkaido's soba association hopes to spread them throughout the country.

[h/t Spoon & Tamago]

All images courtesy of 230 Buckwheat Road Promotion Committee.