Unknown rash getting me down

[Bingbongbooha]

Please is someone able to help me to identify this rash? It’s symmetrical, and under arms, behind knees, inside elbows, in scalp and on the inside of my thighs. It’s INCREDIBLY itchy and after 5 days, isn’t getting any better. Antihistamines don’t touch it. I’m looking online and can’t find anything. Doctor says allergy rash but I’m almost 50, have never suffered with allergies, and haven’t eaten it used anything different. I’ve had a nasty cold, though. Any insights appreciated. Thank you :)

Regardless of what is causing the rash, your GP should be able to offer medications to treat the symptoms.
Steroid cream and stronger antihistamines will help until the rash resolves.