My back, and sometimes other places, itches nearly always. I don’t have a rash unless I scratch it. I’ve had several rounds of allergy testing, and I’m not allergic to anything.
I do, however have AERD, which in a nutshell is overproduction of leukotrienes. I don’t notice a difference with heat, but I think stress really aggravates the itching.
So far, doctors have not given me good answers, and Allegra, which used to keep it at bay, is not helping anymore.