In general, physicians do not have strict recommendations as to how often hair should be washed. This is because there is a lot of variation in individual hair textures, activities which would dirty the hair, and individual oil secretion. In general, it is a good rule of thumb not to wash your hair too much (more than once per day) and not to little (at least once every few days). Anything in between these two is probably acceptable. Washing your hair simply removes dirt and oil from it, and if done correctly should not have any detrimental effects. If your scalp itches after a few days of not washing your hair, then you may have a problem with your scalp such as a dandruff and may benefit from using a ketoconazole or selenium shampoo. I suggest as a first step you should schedule an appointment with your primary care physician
. He or she can take a close look at your scalp and see if you have flaking skin, or even a fungal infection that could explain your itching. If you do have this problem, them your doctor
can recommend treatment. If you don't have this problem, then you should wash your hair as frequently as makes you comfortable.