Just after washing the scalp itchy, may be related to contact dermatitis, may also be due to folliculitis, seborrheic dermatitis and other causes. 1. Contact dermatitis: common in allergic people, may be allergic to shampoo, conditioner, etc., there may be just after washing scalp itching, there may also be scalp erythema, pimples and so on. 2. Folliculitis: may not pay attention to scalp hygiene leading to bacterial infection of the hair follicle and its surrounding tissues and so on. When the scalp area suffers from folliculitis, under the stimulating effect of inflammation, resulting in pain, itchy pimples and pustules on the scalp area, which may cause itchy scalp just after washing the scalp. 3. Seborrheic dermatitis: the cause is unknown, may be related to environmental factors, genetic factors. It occurs in the head, face, armpits and other parts of the head, when the head appeared seborrheic dermatitis, there will be scalp greasy scales, accompanied by itching, may cause the scalp itchy just after washing the head. Itchy scalp just after washing the head, may also be caused by other diseases. It is recommended that patients seek medical attention as soon as possible, after a clear diagnosis, to give targeted treatment.