Could DS have a dairy AND a soya allergy?? How to get him tested?

[jennijones]

This is my first post here.
I suspect my DS (3 1/2 yrs old) has a dairy allergy and possibly a soya allergy too, but I'm not sure how common this is, or how to get it diagnosed properly.
Last summer, my DS developed a horrendous rash on his legs and elbows. Within days, it got so bad he had to be hospitalised and was put on intravenous antibiotics, as bacteria had gotten into the open sores and caused his legs to become severely infected. We were seen by several specialists who were all puzzled as to the cause of the rash.
Since the initial infection settled, he has had small, itchy spots on his elbows and knees and several flare-ups of large, itchy blotches, which have required steroids and/or antibiotics.
To cut a long and very frustrating story short, we were told that the rash was most likely an allergic reaction but no-one was sure what might have caused it, and none of the specialists were willing to investigate further. It was suggested that it could be anything, from any food to grass, to pollen, to animal hair, to washing powder, to chemicals,...the list was endless.
It was recommended that we kept a diary of "everything" to help us establish the root cause (I'm assuming this was suggested by people who do not live in the real world!?).
Anyway, we started to exclude some food groups and, just before Christmas seemed to strike lucky with dairy - within days of cutting out all dairy products, the rash on his elbows and knees disappeared completely. During this time, I tried giving him soya milk, but he hated it, so we ended up using goats cheese and yoghurt and almond milk with brilliant effect.
Over Christmas, we let his diet slip a bit. Ok, quite a lot - he has two older sisters and I just let him eat whatever they had for about 3 weeks. His rash gradually reappeared during this time.
Since the new year, we have cut out dairy again but the rash is still there. It has been driving me crazy - I was so sure we knew the source of his allergy, but the rash just hasn't shifted! It only just occurred to me that the only difference to before Christmas is the fact that I have finally convinced him to have some soya products - he now loves soya ice-cream and the flavoured soya drinks you can get, like strawberry and chocolate.
So, my questions are:
Does anyone have experience with allergies/rashes developing at this age? Most existing posts seem to be about babies diagnosed when they are tiny.
Is it common to have a soya AND a dairy allergy?? Do a lot of children suffer from both?
How do I get my DS tested? I have been to my GP as well as the pediatricians in the hospital with this problem, but they all seem to just sit on their hands and shrug the problem off - nobody seems to care or to be willing to do any further testing at all!
Sorry this post ended up so long!

[trixymalixy]

It's very very common to be allergic to both dairy and soya. The proteins are very similar.

You will need to get a referral to be tested. However tests just give an indication of whether they are likely to be allergic, the only true test is the reaction when eating the food.

[Bert2e]

1/3 of babies with a dairy allergy are also allergic to soy so it is very possible. Many GPs wont test, remove both from his diet and if the symptoms go away that will be proof enough. Ask to see a dietician via your GP and go from there.

[frazzledbutcalm]

The only way to test for milk and soya allergy is to remove them completely from the diet, then when all symptoms have gone, introduce 1 of them back in and see if there's a reaction. Then start all over again and reintroduce the 2nd one. Ds busy going through allergy testing. He's now on a wheat, milk, soya and egg free diet!

[chloejaynemummy]

my LG has cmp but also reacts to soya she's ok with tiny amounts but soya milk and yogurt make her sick and bad nappys xxx

[jennijones]

Thank you all very much for the advice. As of this morning I've excluded both dairy and soya from his diet and will take it from here... xxx