Dark Bumps All Over Body, Constant Scratching. Steroid Creams Not Helping. Cure?

HI, my mother who is african american has had a skin problem for the last 10 years. There has been no diagnosis. She has been prescibed steroid creams and has tired many products on the market. She has dark bumps which have gotten bigger in size over time all over her body including her face. She is constantly scratching her skin. I now feel there might be something she is not being honest about possibly drug use, because she is young and in shape I am not sure what this skin ailment might be.