Dandruff is a harmless condition in which dead skin is shed from the scalp, accumulating in the hair and sometimes causing itching. It is commonly due to seborrheic dermatitiswhich is associated with overgrowth of a yeast that normally lives on the skin. Other causes include eczema), psoriasis and scalp ringworm (tinea capitis).
Dandruff usually clears up with regular use of an antidandruff shampoo.
If it persists despite such treatment or is accompanied by other symptoms, a doctor should be consulted to investigate possible causes or prescribe a stronger treatment.