Dear Doctor, My 14-year-old son always returns from school with serious dandruff. What exactly causes this and I wonder whether it can be treated permanently. Can dieting help? Olivier Dear Olivier, Dandruff is a skin condition affecting the scalp. It causes a itchy and flaky scalp. It occurs more in boys and at a young age. The exact cause of dandruff is unknown. It is said to be due to genetic and environmental factors causing overgrowth of skin cells. Excess dryness of the scalp is said to be one such predisposing factor. Use of hot water for hair wash, use of harsh shampoos for the hair, lack of oiling, poor hygiene, all these are said to contribute to dandruff formation. Some cases occur due to yeast-like fungus. Psoriasis or eczema of the scalp can also cause dandruff. It can be due to allergy to some haircare product used over the scalp. Food allergy can also cause dandruff. High sugar diet is also implicated. As such, there is no permanent cure for dandruff. Improving scalp hygiene, avoiding use of hot water for head bath, avoiding strong shampoos, are some measures that are useful. Massage of the scalp with coconut, olive or almond oil is useful. Medicated shampoos containing selenium sulphide or salicylic acid, among other ingredients, are used for treating dandruff. It can clear it for some time, but if the underlying cause persists, it can come back again. A diet rich in antioxidants, vitamin B and zinc is useful in providing a healthy skin and scalp. Foods rich in Omega 3 and Omega 6, fatty acids like flaxseeds and flaxseed oil, sunflower seeds, fish, walnuts, are some of the sources of these fatty acids. Dieting has no role in treatment of dandruff. Avoiding a high sugar diet is good for overall health of an individual and also for dandruff.