I have an 8 month baby girl who has diaper rash. it is bright red with a few little blisters. what do i do?

Go see doctor: Sounds like an infection. It could be fungal or bacterial. Have your family doc or pediatrician check it out and prescribe the proper treatment.

Yeast/bacterial: Actually, there are several potential causes for what you describe, including a yeast infection, a bacterial infection (like staph, strep, or others), or a herpes infection. It could even be an irritant or allergic reaction to something that's been applied to the area. I think it'd be best to seek medical attention.