Seborrhoeic dermatitis, also known as seborrhoeic eczema, is a chronic dermatological condition. Seborrhoeic dermatitis is a common reason for visits to dermatology offices. It is estimated that 3 per cent of the general population suffers from it. The disease most often appears during adolescence, which is when the sebaceous glands are overactive. A large number of new cases are also diagnosed in people over the age of 50. Seborrhoeic dermatitis slightly more often affects the male sex, regardless of age. The lesions - especially those on the face - are a serious cosmetic and psychosocial problem for patients. The causes of seborrhoeic dermatitis are complex and not fully understood. Overactivity of the cutaneous sebaceous glands, leading to increased sebum production and changes in sebum composition, is considered to be one of the most important.