Q&A: strangest allergy question ever

First, if your child was fed any formula as a baby, please help your child and other kids by taking a short survey. Amanda from Environmental Working Group says:

"Environmental Working Group is collecting data on babies' exposureto Bisphenol A (BPA), a plastic resin used to line food and formula cans, and found in low levels in formula samples. We are concerned that formula-fed babies have the most intense exposures to BPA of any age group. We've created a survey to gather food and weight information for real babies:

http://www.ewg.org/bpasurvey

EWG is preparing an independent analysis of infant exposures to BPA to present to the National Institutes of Health. When the analysis is complete, EWG will send parents a customized report for their child.

The more data we collect, the more accurate our analysis will be."

Thank you!

Now, on to today's question. A mom who I'm not going to name writes:

"My five-year-old daughter has some pretty bad vaginal irritation. We've been to the doctor twice for it in the past year, and the doctor is convinced the irritation stems from my daughter playing with her genitals at night (as I don't see her doing it during the day). But my mommy instincts say this isn't the answer. My daughter sucks her thumb with one hand and usually cuddles her blanket with the other. The thought that she's also working self-stimulation into the picture in her sleep is a little much. So, the question is, if she isn't causing the rawness herself, what is?

Let me start by saying I've already ruled out molestation (it's a sad commentary on our society when this was my first thought).

I've thought about a detergent allergy, but as the redness is not on the outside skin but more inside, I'm not sure this can be the answer (though feel free to correct me). I've also considered toilet paper, but she only does a cursory wipe--that is, she doesn't dig in there--so I'm not sure that's the answer either.

Then I started wondering if something in her urine could be causing it. I know that babies can get a red ring around their anus with food allergies. Could my daughter's vaginal irritation be caused by a food allergy?

Allergies are new territory for me, so I'm not even sure where to start.  As her uncle is a celiac, I've looked into a gluten allergy, but gluten appears to be more related to the intestines. Could it be a dairy allergy? She drinks more water than anything else, so it's not acid from juice that's irritating her. She's also had some behavioral change that started about the same time the vaginal irritation did (that is, she seems almost bi-polar--happy one minute, throwing a tantrum the next). Ugh, I'm just at a total loss. I'm hoping that one of your readers might have solved a similar issue with a daughter or have some ideas about what I can try to help my little girl. Vaginal pain is a terrible thing to live with."

Let me express my sincerest sympathies to your daughter. I don't think I can imagine the pain and irritation she must be suffering.

It sounds like you've ruled out the big things (gluten, dairy). Have you looked at artificial colors and flavors? What else happened around the same time this started? Did you go on a trip or anything like that?

I really need to go to the readers here, because I just can't think of anything that would cause behavioral changes and also this strange irritation that's not either sexual abuse or some of the classic behavioral triggers (artificial flavors, colors, and sweeteners). Does anyone else have suggestions? Hedra? Enu? Anyone else?