Itchy scalp caused by cervical osteoarthritis?

For the past 18 months I have dealt with an itchy scalp, but no dandruff, no redness or other symptoms. I tried every shampoo imaginable and finally today went to my Dermatologist, who after examining my scalp, asked if I had arthritis in my neck! I do! I have cervical osteoarthritis. Imagine my surprise when he quickly diagnosed and all the pieces of the puzzle came together. He smiled when he said none of the shampoos I bought would help this. He prescribed a topical application - Clobetasol 0.05% twice a day for 2 weeks then 3x a week. He said it might help--the cost to me is $154.63 for one month. I have now asked if there is a more cost effective med. Have any of you experienced this--and if so, how do you deal with it? Is it permanent and will it get even worse as I age?