I had a an itch under my left armpit in Nov. after 2 weeks I went to the dr. and he gave me 100k usp nystatin. The itch went away in 2 days and I finished the tube per instructions. in Feb I had the same itchy feeling in Feb. after 2 weeks and trying creams and hydrocortisone I found a tube of Nystatin cream in my house from 11/04/94. Since it is on the outside of the body and the dr was closed for the weekend I tried it. In two days the itch was gone and I didn't have to go to the dr on that Mon. I finished the tube and the itch as not come back in the last month.
Why did the 20yr tube store in a bathroom work just as well as the new tube?