Large bumps on the body and itchy is usually caused by pathologic reasons, common eczema, urticaria, contact dermatitis and so on. 1. Eczema: Eczema is caused by a variety of internal and external factors of the superficial dermis and epidermal inflammation, often manifested as skin erythema, papules, pimples and other symptoms, often fused into a piece and accompanied by itching. 2. Urticaria: Urticaria is stimulated by various foods, drugs or other factors, resulting in temporary expansion of small blood vessels in the skin and mucous membranes and increased permeability and the emergence of limited edema, often manifested as a large area of the body, accompanied by itching symptoms. 3. Contact dermatitis: contact dermatitis is the skin in contact with certain exogenous substances, in the skin and mucous membrane contact sites occurring in the acute or chronic inflammatory reaction, often manifested in contact with the site of pimples, erythema and other lesions, accompanied by itching. It is recommended that patients go to the hospital in a timely manner, by the doctor to clarify the cause of the targeted treatment. Daily pay more attention to personal hygiene, change and wash personal clothing, avoid scratching the skin repeatedly.