The body itchy scratch a lot of small grains may be hives, contact dermatitis, scabies, etc., need to be specifically analyzed. 1. urticaria: urticaria is caused by the expansion of small blood vessels in the skin and mucous membranes and increased permeability, clinical manifestations of the skin surface of varying sizes of confined lumps, lumps of white or red, accompanied by obvious itching. 2. Contact dermatitis: contact dermatitis refers to the skin or mucous membrane contact with some external sensitizing substances caused by acute or chronic inflammatory skin reactions, clinical manifestations of papules, blisters, erythema, itching. 3. Scabies: human scabies mite parasites in the skin can lead to the occurrence of scabies, commonly found in the thin and tender skin, erythema, papules, herpes and other lesions. The body itchy scratch a lot of small grains may also be caused by other reasons, it is recommended that patients go to the hospital in a timely manner to clarify the cause of the disease.