The feeling of obvious itching caused by yam touching the skin is actually skin allergy. Because there will be tiny burrs on the surface of yam, it will pierce the skin on the hand and make the patient feel severe itching. If some patients have sensitive skin, local redness and swelling will occur, accompanied by obvious papules. In this case, patients can repeatedly rinse their skin with soapy water, which can slightly relieve severe itching, and can also use calamine lotion and glucocorticoid ointment for external use. At the same time, oral antihistamines can also relieve severe itching, such as loratadine, cetirizine, chlorpheniramine and ebastine tablets are all optional drugs. However, if the patient has allergic reaction to yam, he must pay attention to skin protection in the process of washing vegetables in the future.