There are several reasons why you may be experiencing dandruff, including poor hair hygiene, using harsh hair products, or having a scalp that is sensitive to certain ingredients. Stress and hormonal imbalances can also contribute to dandruff, as can certain medical conditions like psoriasis or eczema. Vichy Dercos Dermo-Soothing Shampoo is specifically designed for those with a sensitive scalp and can help to relieve itching and irritation.