Bald and red scalp may be related to seborrheic dermatitis, ringworm of the head or bald folliculitis and other diseases. 1. Seborrheic dermatitis: when there is more sebum overflow in the scalp area, the skin damage can be scaly, with erythema and furfuraceous flaking on the scalp, making the hair fall out or thinning. 2. Tinea capitis: when there is dermatophyte infection in the scalp, four types of tinea capitis can appear in the scalp: tinea cruris, tinea alba, tinea cruris or tinea nigra. Such as ringworm, skin lesions at first for red spots, covered with scales, later formed yellow scabs, remove the scabs, the following can be seen flushed vesicular surface, and can cause permanent hair loss. 3. Bald folliculitis: red follicular papules can be formed on the head, pustules can be formed, rupture or dry up after the formation of yellow scabs, for bald folliculitis scalp prognosis leave hair loss and scarring. Scalp baldness and redness as early as possible to the hospital specialist consultation, clear cause after targeted treatment.