Rash under arm (pic)

[Polkadotties]

Anyone know what this could be, obviously if it gets worse will go to the GP.
I noticed a couple of little patches a few days ago, thought nothing of it.
Was putting deodorant on this morning and noticed that it's spread and there is now a big patch.
I've had pityriasis rosea before. That started off with a definite herald patch on my back.
It doesn't itch, wouldn't know it was there if I hadn't have seen it.
No change to shower gel, washing powder etc

Might help if I attach pic

Could be ringworm? Pharmacist would be able to take a look if you ask for a consult.

Do you catch ringworm off animals?
I have a horse, a cat and recently got two rabbits

Have been having a good look everytime I go to the toilet, office is like a fridge so I have a cardigan on. Not sure if the bigger patch has a ring or not.
Will pop to the chemist at lunch and see what they say, if not there's a walk in centre near where I work.
I won't be able to get a GP appointment at my actual doctors next week and don't feel like seeing them at the moment as I am seeing a private GP for depression and my notes haven't been transferred over yet

Try a tube of Daktarin or similar from the chemist in case it's a fungal rash, that should clear it up in a couple of days. Won't do any harm anyway.

If you think it might be spreading make a GP appt just as a backup. When I had it I needed a stronger antifungal cream and tablets from the GP.