Bumps on the back of the head, and especially itchy, may be related to folliculitis, eczema, hives, contact dermatitis and other diseases. 1. Folliculitis is an inflammatory skin disease that is usually characterized by pain and redness, and some people may also experience itching. 2. Eczema is an inflammatory skin disease caused by a variety of factors, in addition to the rash, in the clinic will be manifested as recurrent episodes and intense itching. 3. Urticaria is due to allergens into the body after the expansion of capillaries, increased permeability and the formation of a kind of allergic reaction disease, to the main features of the wind, and will be accompanied by intense itching. 4. Contact dermatitis is due to local skin contact with some kind of goods and produce an allergic reaction, often occurs in the exposed parts, mainly manifested as itching and skin rash. Due to the many factors affecting the condition, it is necessary to consult a doctor first.