Itchy hairline may be caused by physiological factors such as not paying attention to hygiene, or it may be caused by seborrheic dermatitis, atopic dermatitis and other diseases. 1. Physiological factors: If you don’t wash your scalp for a long time in your daily life, it will lead to poor local hygiene, which will lead to itchy hairline. 2. Seborrheic dermatitis: the etiology is still unclear, and may be related to heredity, microbial infection and other factors. Patients will appear local erythema, flaking and other symptoms, accompanied by itching, can be seen in the scalp, face and other parts. 3. Atopic dermatitis: the cause of the disease may be related to heredity, immune abnormalities and other factors, patients will appear dry skin, itching and other symptoms, can be seen in the hands, scalp, trunk and other parts. There are more reasons for itchy hairline, after excluding physiological factors, it is recommended to consult a doctor for examination to clarify the cause of the disease.