Hair a day without washing is very oily and itchy is likely to be caused by seborrheic dermatitis, can take loratadine and other anti-allergic drugs, vitamin B6, doxycycline and other drugs to treat, and at the same time to improve the habits of life. The hair is very oily and itchy when it is not washed for a day, it is likely to be seborrheic dermatitis related to excessive secretion of endocrine lipids, and there will also be erythema, dandruff and so on, you need to take loratadine and other anti-allergic drugs under the guidance of a doctor, vitamin B6, doxycycline and other drugs to regulate the use of selenium disulphide lotion, if necessary. In addition to the above medication, the occurrence of seborrheic dermatitis signs and symptoms of the above should also pay attention to the adjustment of lifestyle and dietary habits, as much as possible during the conditioning of a light diet to reduce the intake of greasy food, avoid staying up late, avoid scratching and stimulation of the scalp. It is recommended that when the symptoms and signs of life and work cause serious problems, it is necessary to consult a doctor to identify the cause of the disease in the doctor’s guidance to carry out targeted treatment.