After peeling the yam arm is very itchy is mainly due to the yam contains plant alkali irritation of the skin caused by, you can first use a lot of water to rinse the affected area, the local can be coated with edible vinegar; if the itching is more serious and there are erythema, then the use of anti-allergy drugs for treatment. As yam contains plant bases, some people may experience itching, erythema, pimples, swelling and pain after contact with yam. If the itching is only mild, the affected area can be rinsed with plenty of water, and then some edible vinegar can be applied locally, which can play the role of neutralizing the phytochemical alkaloids and relieve the symptoms. If the symptoms are severe, you can use mometasone furoate ointment to apply externally, or use drugs such as levocetirizine hydrochloride oral solution for anti-allergy treatment. Those with severe symptoms should go to the hospital and use medication under the guidance of a physician. Gloves should be worn as much as possible when touching the yam to prevent recurrence of symptoms.