Can you put desitin (zinc oxide diaper cream) cream over top of nystop powder?

OK: Desitin (zinc oxide diaper cream) is a barrier cream (zinc oxide) and Nystop is a anti-fungal powder. For anti-fungals to work they need to be placed on the skin directly --as you have done. The desitin (zinc oxide diaper cream) will just 'seal out moisture' --so not a bad idea.

Depends: The important question is why? What rash/problem are you trying to treat? It sounds like you are dealing with some sort of yeast?. There are lots of ways to help treat it, including other topicals, shampoos, probiotics, food changes as well as powders and oral medications if need be, it may be important to find out why you are having trouble, diabetes, even hiv, can increase the risks for yeast.