Exercise induced hives

[CherryLeaf]

I’ve exercised quite a bit before... gentle jogging/classes etc periodically over the years.. had a bit of a break when the weather was rainy lately and just restarted. The last two runs (no longer than 30 mins, no different to previous) I’ve started to get hives all over my body! Doesn’t match where my clothing is but worse in groin and armpits. Doesn’t affect my breathing or anything. It gradually goes after a cool shower and an hour later.
Am I ok to keep running? This time I ran in vest and shorts so trying to keep clothes minimal to not over heat, plus ran at 7am so not running in heat. I don’t really understand the sudden change.
Has anyone had this? Does it tend to just right itself? I’ll get some anti-histamines on standby. It’s a bit odd tbh. Any advice gratefully received

Sounds like sweat plus pollen irritating your skin?
I find hot sweaty skin gets irritated more easily anyway (eczema sufferer) but I get a rash if I go near grass when I'm at all "moist" from exercise
DS's hay fever has just started this week so I'm guessing pollen?

It may be an allergy called urticaria.
It's a reaction to temperature change. You could try an anti- histamine before you exercise? (Non drowsy of course!!)

I suffer from chronic idiopathic urticaria but exercise definitely makes it worse. I take a low dose of antihistamine (5ml of kids benedryl) and it keeps them at bay including after exercise. I used to have to take fexofenedine daily but don't need that as much anymore

Still can't have red wine though...

did you have covid?
I know a couple of people who developed this after they recovered.
coolish shower after exercise & antihistamines seem to help them.

DD had this for a few months after the flu. It’s urticaria. Take antihistamines and do exercise gradually. It did go away but it took several months