Seborrheic dermatitis , also known as "dandruff", "cradle cap", is an inflammatory skin disease in which scaly, red, itchy patches appear over scalp. These patches may also appear on the face & upper body. These are the areas with many sebaceous glands, which produce oil. It can result from different factors, depending on your skin type and sensitivities. Your dermatologist can help you find one that’s suitable including shmpoo, cream/lotion & tablets.