Sounds like a yeast infection....stick with the vagicil or the nystatin ointment and feed her a little yogurt every day.
Linda C

I agree with Linda, yeast infection. Good luck, Christy

My DD has food allergies. The diaper reaction was the first clue we had (i.e. wherever the poopie touched her little bottom, she had what looked like a sunburn).

It started when she moved from formula to people food.

In DD's case it's Yellow Dye #5 and #6. This is commonly found in Kraft products (like mac n cheese, most every instant pudding, etc), drinks like Sunny-D, a lot of junk foods, etc.

It is also in shampoos, bubble baths, etc.

Other symptoms she had was bad exczema on her face, and recurring upper respiratory issues bordering on asthma.

Hope this helps!

My daughter has something very similar, and according to her doctor, it's exczema (she gets it where her thighs meet her vaginal area, where her underwear lies). She also gets it on her feet, and sometimes her belly button. We use Aquaphora baby soap and she has been prescribed elidil cream. She will do okay for awhile, and then have a big flare up. My husband had exczema as a kid, so we at least had a clue to what it was. Does she get this rash anywhere else?

I know it's probably too simple, but could it be from her drinking/eating a lot of Orange Juice or something in the Tomato Sauce family?

Forgot also to add, that it could be the type/brand of diaper. Even if she hasn't had a problem before, some are so drying on their sensitive skin that they can cause a rash. I know you said you changed sizes, but have you tried a different brand? Try a generic brand that isn't too absorbant and see if it helps.

Try this site, it is to help diagnose a rash. Good luck :) Christy

Here is a link that might be useful: Family Doctor

Here's another site about Diaper rash in general. Maybe it will give you some ideas or things to try. Be sure to check with your doctor if it keeps coming back.

Here is a link that might be useful: Diaper Rash

I'm thinking too yeast infection. Let her run around bare bottomed for a while after changing her or use a hair dryer (on cool) to make sure she's throughly dry. Make your own diaper wipes with a vinegar water soulution (gets the PH back in balance). Yogurt with active cultures in it (also gets PH in balance). Change her diaper more often...keep her bottom as dry as possible. May have to push potty training as a way to get that bottom dry (I know she's young for it, but keeping the bottom dry in key here).

Vickey-MN

My son has a similar rash from time to time. Now that he's a little older, he'll communicate that he has a "boo boo" on his tooshie. When this happens, instead of irritating it and using diaper wipes, I'll give him a bath with a little baking soda in the water. After the bath, we found a product called Bordeaux's Butt Paste, we slather that on and add a little baby power on top of that, and amazingly the rash will diappear within the next couple of diaper changes. I have tried to track exactly what's causing the rash and it seems to appear when he drinks fruit juices. He doesn't seem to have any issues wuth fresh fruit, so I know it must be something that's being added to the juice.

For similar situations I've been using a diaper cream that seems to be a great solution. It's called BabyPaste5.0 and you can look at the ingredient list, it contains no toxins or allergens. It actually uses a small amount of vinegar to keep the cream at the same pH as skin (pH imbalance is supposed to help cause diaper rash). You can buy it online, you can even get it in this push up one ounce container that I keep in my pocket book for easy on the go use. Hope I helped. BabyPaste Link below.

Here is a link that might be useful: diaper rash treatment