Seborrheic dermatitis, also known as seborrheic eczema, is a chronic, papular, scaly superficial inflammatory skin disease that occurs in areas where sebum is excessively secreted. It is more common in adults and newborns, but can occur at any age. The main symptoms include follicular papules appearing on the scalp, face, chest, and back, which then merge into large, yellowish-red or dark red patches. These patches are covered with greasy scales and crusts, and may be accompanied by exudation, crusting, erosion, and eczema-like changes. In severe cases, it can spread throughout the body, causing diffuse erythema and significant scaling all over, along with varying degrees of itching. This disease is a chronic condition that can recur repeatedly. It is one of the most common diseases in dermatological practice. Therefore, patients with seborrheic dermatitis should consult a dermatologist.