A severe skin irritation caused by excess sebum production in densely hairy areas, such as the scalp, neck and back, complicated by the presence of the same yeast ( Malassezia furfur) that is associated with dandruff
appears to relate to Malassezia furfur yeasts that live on the scalp, face and sometimes elsewhere. It is a common, harmless, scaling rash affecting the face, scalp and other areas. Dandruff (also called pityriasis capitis) is seborrhoeic dermatitis of the scalp.
Seborrhoeic dermatitis, commonly known as cradle cap, is a condition of the skin (usually on a baby's scalp) which causes crusting, scaling, and discolouration. It usually disappears during the baby's first year.