Getting tested- what am intolerant to?

[Peachyscream]

Ive been taking 1 certirizine daily for years, otherwise I get itchy, all over my body. Now they're not working and the gp gave me BDJDJ but they're not working AT ALL. My whole body is covered in welts from scratching so much, even my scalp hurts. The palms of my hands look fine but they feel like they're burning.
I know I need to take a test to figure out what it is, but I have no idea where to start. The gp tested me years ago- I think it was for the 7 most common things and they were all fine.

Can someone advise where I should get tested from? I know there's tests you can purchase, some advice would be appreciated, and how much should i expect it to cost?

The gibberish was meant to say 'Fexofenadine' 120mg

The sort of tests you can purchase for intolerances (York tests and the like) are junk science.

Only proper IgE testing by a properly qualified doctor can identify actual allergens.

Do you keep a diary of what you eat/use etc? Have you done exclusion diets?

What has your GP diagnosed you with? I'm guessing chronic urticaria? A typical meds regime for that would be 4 x 10mg cetirizine daily. Not all urticaria is the result of an identifiable allergen though, which makes it particularly tricky.

Thanks for the swift reply!
GP hasn't diagnosed me with anything he just said try these tablets for 2 months. It's the 2nd day and I'm red raw.
I haven't tried eliminating anything tbh, where do I start, I'm itchy alllll the time

Years ago, I had acupressure tests done by a dietician that are supposed to indicate food intolérances/allergies.

I wonder if a dermatologist referral would be worth asking for, as you don't actually know if it's even an allergic rash, so that really needs checking out first before going down the route of allergy testing.

Do not waste money on crappy tests though!

The thing is, it's not a rash! The welts are caused by my scratching (should have clarified that) but I'll ask the GP what I can do about seeing a specialist.
Last night I had a cold shower, took 3 certirizine and a Fexofenadine and slathered myself in coconut oil. Then it calmed down enough for me to sleep