Because the saponins contained in yam mucus are one of the allergens.

Contact dermatitis may occur after contact with human skin. The most common symptom is that the hands feel itchy. In severe cases, symptoms such as redness, swelling, and stinging may occur.

The time when allergic symptoms appear often varies from person to person. Some people react quickly and feel itchy when they cut their hands, while others may take a while to react. At present, there are indeed many clinical cases of contact dermatitis caused by yam.

Extended information:

Washing yam to avoid itchy hands:

1. Baking:

Due to saponins that can easily cause allergies More afraid of heat. So if you are afraid of allergies, after peeling or cutting the yam, wash your hands and then dry them on the fire to relieve the itching.

2. Wear gloves:

You can also nip it in the bud. Before handling yams, you might as well wear rubber gloves or put a plastic bag on your hands, and then Peel or cut into pieces to prevent contact with substances that may trigger allergies, and you don't have to worry about itchy hands.

3. Vinegar soaking:

Use boiling hot water to wash the yams and boil them directly in the water. In this way, the yam skin is basically cooked, the original allergens are destroyed, and you will not be allergic if you touch it again. Soak your hands in dilute vinegar for a while before handling the yams.

People's Health Network - What to do if your hands are itchy after washing yam?