Mother knows best?

Do mom's know best? My mom told me that Justin's eczema on his arm and ears may be from me using too much Desitin. I was told not to use so much Desitin after diaper changes, when I was a kid, she didn't use much on me and I was fine. She also said that cousin Micaela was fine without the use of much Desitin. I'm not too sure where I stand. Maybe I won't use so much anymore, but if it'll prevent diaper rash, I'll keep using it.