Seborrheic dermatitis – symptoms, causes and effective treatment

Seborrheic dermatitis or seborrhea manifests itself as scales on the scalp or face and in most cases is the cause of dandruff accompanied by redness and itching of varying intensity on the scalp, while on the face it appears as redness with small scales. Which can also be accompanied by an itchy feeling. And what are the causes of this skin disease and how is it treated?