It is a kind of contact dermatitis in medicine. Since not everyone has this symptom when exposed to yams, it could also be an allergic reaction.

It is currently believed that the factors that cause this kind of contact dermatitis are the saponin contained in the yam skin or the plant alkaloids contained in the mucus. The skin will itch when it comes into contact with these two ingredients. If the skin is dry and chapped or the skin is damaged, it is more likely to cause a stinging reaction, and you should avoid contact.

If you have symptoms of itchy hands, you can try the following methods: 1. Apply your hands first Wash your hands, and then apply vinegar on your hands, even under your nails. The itching will gradually disappear after a while. This is due to acid-base neutralization. 2. You can also roast it on the fire and turn your palms repeatedly to heat your hands, which can decompose the saponin that has penetrated into your hands. But be careful and don't burn your skin. 3. Putting your hands in rice and rubbing them repeatedly can also relieve itching