Itchy hands after cutting yams need to be promptly cleaned of alkaloids on the hands and medicated with allergy symptoms.
Yam contains alkaloids that are irritating to the skin and can cause itching when they come into contact with the skin on the hands. Alkaloids are chemically unstable and decompose when exposed to heat. When itching occurs, the alkaloids can be broken down by adding white vinegar to hot water that is not too hot for your hands and soaking your hands in hot water for a few minutes.
Alkaloids can sometimes cause an allergic reaction with redness and intense itching. It can be treated with topical glucocorticoid creams such as mometasone furoate cream and hydrocortisone butyrate cream.
Take precautions when cutting yams, preferably wear plastic gloves. If itching starts on your hands do not hit the skin or rub your eyes to avoid getting alkaloids on normal skin.