Dandruff called seborrhea is often recurrent. Some special shampoos contain anti-fungal meds and others have cortisone cream. The standard prep contains zinc, but others may have selenium (Head and Shoulders vs. Selsum preparations).

Use a shampoo containing 2%-4% selenium sulfide. Lather scalp and rinse off. Lather again and leave shampoo on for 5-7 minutes. Using this regularly should control your dandruff.

Nizoral (ketoconazole 1%), Head and shoulders, Selsun blue, Neutrogena Tgel/Tsal, DHS are all good brands. Ensure you are using the products as recommended on the label (often twice a week depending on the product). If not clearing I recommend seeing your local board certified dermatologist. This is a recurrent problem easier to keep clear with maintenance therapy than to clear it when active.

Now is the time to spend money seeing a specialist dermatologist to get a proper assessment.

I would recommend ketoconazole shampoo.