Dandruff is a mild form of seborrheic dermatitis that is characterized by a flaky, itchy scalp; it affects approximately 50% of adults worldwide. It commonly begins during puberty and is more prevalent in men and boys, with no link to poor hygiene.

The main signs and symptoms of dandruff include skin flakes on the scalp and other areas, as well as an itchy scalp. Dandruff can occur independently or may indicate underlying health issues such as HIV/AIDS, neurological disorders, or congenital disorders.

Dandruff is typically diagnosed through a visual examination of the scalp. It is essential to differentiate it from other similar conditions like atopic dermatitis, tinea capitis, rosacea, and systemic lupus erythematosus.

Dandruff is primarily treated with hair and scalp products, particularly shampoos that contain antifungals, corticosteroids, or compounds that reduce skin turnover and flake accumulation. Many of these treatments are available over the counter, but some may require a prescription.

There is limited research on supplements for dandruff, but vitamin A may help by reducing sebum production. Although micronutrients like biotin and vitamin B are often recommended, evidence of their effectiveness is lacking, though some studies suggest that oral probiotics might improve dandruff.

The relationship between diet and dandruff is not clearly defined, but reducing intakes of dietary fats, glucose, and acetate may help decrease sebaceous gland activity and improve dandruff. Additionally, caloric restriction could lower sebum production, potentially alleviating the condition.

Shampoos with tea tree oil have demonstrated positive effects on dandruff, although further research is needed to confirm these findings.

Dandruff is thought to be caused by a combination of factors, including high sebum secretion, the presence of Malassezia yeast, and individual characteristics such as skin barrier strength, immune response, genetics, and stress levels. The fact that Malassezia yeast is also found on individuals without dandruff indicates that personal factors play a significant role in the condition's development.