Hi Truthsweet.
Your pediatric doctor sounds like she's too far up her own arse!
I would be asking demanding a referral to see an pediatric allergist. Your DD's reaction to wheat is not normal and if it's doing that to her bottom it's no wonder she's so upset whilst it's still inside her - poor thing. It must be so upsetting for you too.
I really think that as you have allergies and your other DD does too, then this needs to be taken more seriously. I really think that for some people diet can really aggravate eczema, so the doctor is a bit mad to look at one without even considering diet esp if you have the evidence.
If you can, have a look at the NICE guidelines here the PDF tells you what sorts of things require a referral to a specialist.
Also, if you speak to the Allergy UK Helpline, they may be able to help with some advice, and will also be able to tell you where your nearest specialist clinic is. Most allergy clinics have specialist dieticians who work with the allergists so you'd get to see both if you were referred.
We were under a dietician at our local hospital for about 18 months before I realised that we had to ask to be referred to a specialist. They were nice but just not specialist enough. They also organised skin prick tests and DD also tested negative to wheat. After 2 they decided to do a challenge and she was so so ill with a really bad reaction. They didn't even know to confirm the Skin Prick tests wiith blood tests. In the end I had to ask to be referred to see an allergist and they have been so so much better.
If you request this from your GP he/she has to refer you. With what your DD is going through and your family history I think you've got a good reason to be asking. Also, if your GP is negative or dismissive, take the Nice Guidelines with you.
I've learnt the hard way that if you don't ask you don't get :(
Sorry if I sound a bit tetchy, but I'm getting wound up on your behalf.
Good Luck with this and hope your pregnancy is going well and that this isn't stressing you out too much. (my post I mean. It's not meant to, honest)
Take care xxx