The big red bumps on the body are very itchy, considering the insect bite dermatitis, urticaria, folliculitis and other diseases. 1. insect bite dermatitis: itchy red bumps on the body may be the insect bite reaction, is the skin caused by insect bites, manifested in the bite of the skin lesions, accompanied by itching, lesions manifested in red doughnut-like damage, localized edema, erythema, blisters and other changes. 2. Urticaria: Urticaria is a limited raised in the skin, mucous membrane surface edematous mass, for the size of the white or pale white wind, often accompanied by itching and other symptoms. The cause of the disease is related to physical stimulation, food, drugs and so on. 3. Folliculitis: Folliculitis is mainly caused by bacterial and fungal infections, and the triggers include skin damage, hair plucking, sweating and other bad habits, which is manifested as red papules centered on hair follicles, accompanied by itching. If the skin suffers from folliculitis, large red bumps on the body that are itchy can also occur. There are more causes of itchy red bumps, so it is recommended to consult a doctor for a clear diagnosis.