P.M.
My 5 yr old daughter does this and has super-sensitive skin. We found that Weleda's Calendula cream (diaper or baby) works best. She doesn't like the heavy, greasy feeling of things like Vaseline or Aquaphor. Like so many others have suggested, we apply it at night before story time. She calls it her "healing cream". By morning, there's barely a hint of the redness and she's no longer in pain. We've tried other creams & ointments but she responds best to this one. It is expensive when compared to other options but it works wonderfully. In the summer, she gets raw dry patches of skin so we use this for that too. It's great stuff!