Seborrheic dermatitis is an inflammatory change of the skin that occurs in the seborrheic (oily) areas such as the upper chest and armpits of the scalp, and there is a difference between dry seborrheic dermatitis and oily seborrheic dermatitis. Dry seborrheic dermatitis has dry skin and is characterized by itchy, flaky skin on the scalp. The face is usually seen in children, for coin-shaped light-colored spots, a little flakes, also known as simple pityriasis. Oily seborrheic dermatitis occurs in those with a lot of oil, commonly as greasy erythema, papules, heavy may have vesicles, exudation and greasy crust, for cases with exudation is called seborrheic eczema. For the treatment of dry seborrheic dermatitis, usually try not to use alkaline cleansers, and use skin creams and conditioners topically after washing. You can usually take vitamin B6 orally and eat more vegetables. The onset of oily seborrheic dermatitis is related to the overgrowth of Malassezia and other bacteria. As Malassezia is the normal flora of the human body, so oily seborrheic dermatitis is easy to recur. Treatment principles: 1, reduce oil, pay attention to skin cleanliness; 2, antibacterial drugs, preferred azole topical drugs such as clotrimazole ointment, miconazole ointment, bifenazole ointment or ointment, terbinafine ointment, etc.. 3, if there is osmosis, seborrheic scabs, then antibiotics should be taken .