Seborrhoeic dermatitis

Seborrhoeic dermatitis is a common, long-term skin condition that affects the areas where oil glands are most active: the scalp, eyebrows, the sides of the nose, behind the ears, and sometimes the chest and upper back. It usually shows up as redness with flaky scales that look white or slightly yellow and feel greasy rather than dry, often accompanied by itching or a burning sensation. On the scalp it is frequently mistaken for ordinary dandruff, and in babies the same condition appears as cradle cap. Although the exact cause is not fully settled, it is generally linked to an overgrowth of Malassezia, a yeast that lives naturally on the skin, combined with how strongly an individual’s immune system reacts to it. Sebum levels play a part too, which is why the condition favours oily areas rather than dry ones.