Dandruff is particularly abundant and large pieces may be caused by seborrheic dermatitis, according to the different symptoms, can be divided into scaly and crusty type. 1. Seborrheic dermatitis is a chronic, recurrent, inflammatory skin disease commonly found in seborrheic areas such as the head, face and chest and back, often accompanied by varying degrees of itching, and the scalp damage can be divided into two main types: scaly and crusty. (1) Scaly: often erythematous with small flakes of bran-like flakes and thinning or loss of hair. (2) crust type: mostly in obese people, scalp thick accumulation of flaky, sticky greasy scabs, scabs under the inflammation is obvious, the scalp gap has erosion, oozing. 2. The etiology of seborrheic dermatitis may be related to Malassezia colonization, impaired skin barrier, diet, lack of vitamin B and so on. Patients need to maintain a regular diet, get enough sleep, reduce the intake of fatty and sugary diets, and avoid alcohol and spicy foods. Use mild cleansing products to take care of the scalp, avoid over-cleaning, and strengthen oil control and moisturizing. It is recommended that patients with the above symptoms go to the hospital in a timely manner for a clear diagnosis and standardized treatment as prescribed by the doctor.