A dry scalp may be caused by excessive washing of the hair. This occurs particularly with medicated or perfumed shampoos and soaps. All soaps and shampoos tend to remove oil from the skin.
The first step in treatment is to recommend washing the hair no more than twice a week and to use a very mild baby shampoo.
After washing, massage a small amount of baby oil into the scalp. This will help replace any lost oil and reduce dryness and itching. It will take several weeks for the scalp to recover but if done consistently should return to normal.
In severe cases, gels or lotions containing a steroid can be prescribed to settle the scalp inflammation. These should only be used short term until the discomfort and skin flaking have settled, and then the sensible shampooing methods outlined above should be followed.
This problem often becomes more acute as the hair becomes thin with age, therefore more of the soap or shampoo can penetrate the unprotected scalp.