My daughter has allergies/intolerances & I can't figure it out

[Bluemum29]

My daughter is almost 2. When she was about a year old I suspected something wasn't right with her diet, as she had never done a solid poo and she had patchy rashes on her skin. Its taken me almost a year to see a specialist, who has advised that they don't test for allergies/intolerances anymore (in Edinburgh) and we have to keep trying eliminating things. We have tried eliminating various things over the past year, and we are fairly certain she has a dairy and a gluten intolerance (dairy stronger than gluten), but I'm not 100% as even when these items are eliminated, although we see improvements, every now and again, she has runny yellow poo, with rashes over her body. I would just love to know what is wrong for certain, and I'm at a loss what to do next.
I already know she can't have egg - as she had spots all over her body when she tried just a tiny amount at 6 months. (Her sister has the same allergy).
Are there any tests that are actually reliable?
Does any one have any advice on what to do next?

There are tests for immediate reactions but these are unreliable in young children.
Delayed allergies, those that would affect digestion can only be diagnosed by removing a food and seeing if things get better
Stools can take a long time to improve. My daughter has multiple delayed food allergies. We started removing foods at 4 months when breastfed but it took until 14 months to get her symptom free. Allergies are just one of many things that cause her bowels to be upset other things include teething, colds and stress. The night before we moved house she did 8 poos in 2h!
She's 4 now and it's only in the last few months that she has consistently had solid poos! She still has regular rashes that take weeks to clear after a reaction and are clearly triggered by other things too. It was painful but food diaries and removing foods, tweaking her diet, paying close attention to what we replaced removed foods with is how we slowly got a handle on her allergies. I replaced dairy with more tomato and coconut based foods but she was allergic to both of them too. We tried the petit filous almond yoghurts and discovered a tapioca allergy. She reacts to the pea protein in alpro oat milks. Had we not previously safely given almonds and oats we would have assumed they were the culprits as they are much more common allergens. Absolutely anything can cause a reaction. The hardest one for us to identify was an allium allergy. She can't have any onion or garlic.

You need to remove the potential allergen for a good length of time. It can take a couple of months for it to leave her system and then more time for her body to recover without the allergen. My dd is celiac. Once we removed gluten from her diet we saw an immediate improvement but it took months for it to fully show obvious difference. My dd did have allergy testing as a baby and did come back positive for a couple of things. She eats these now without issue so it is unreliable. Her bloods for celiac disease came back as normal and negative. We ended up going private because I was convinced and the dr explained this is not uncommon and these tests are known to be unreliable.

Look up other symptoms for the suspected allergy and see if you can spot any lesser known symptoms that you may have missed as this could give you a better idea. I didn't realise how much my DDs gluten allergy was as affecting her moods for example.

Remove one at a time and keep it away for a good couple of months at least. Slowly reintroduce and monitor symptoms. You have to also be very careful about cross contamination and the allergen being in products you may not realise. You will need to become a pro at reading labels.

The mood and being irritable play a big factor for us.
My teenage son has sudden onset suspected dairy allergy. He was so cranky, but guess some of it could be related to pain and not feeling well.
If he has a mishap and it’s in something bizarre he’s not realised I can sometimes tell by the way he is!

"Her bloods for celiac disease came back as normal and negative. We ended up going private because I was convinced and the dr explained this is not uncommon and these tests are known to be unreliable."

That's strange. We thought my DD was celiac, as there is a lot in my family (6 people including my sister and father). When we saw the gastroenterologist consultant he said her celiac tests were negative, I asked - having seen it on Mumsnet - if it is possible to be celiac but get negative blood testing. He said it is theoretically possible but it is very rare. Of course she turned out to have inflammatory bowel disease.