Summer sores/scratches/dew poisoning on muzzle? How to treat?

Hello! Hoping someone may have some ideas about what might be plaguing my appy. Last summer, he got some scratches on his heels, and my vet had me mix desitin, dmso, and Nolviasan to apply 1-2x daily… this seemed to clear them up. This summer, they’re back, and the same formula is being applied, but there are also some new symptoms (or maybe a completely different ailment?) he started getting the little oozey sores on legs or in folds, and dabbing the dmso/desitin mix on these has them pretty much cleared up, but Now there are a few dots on his pink muzzle… and I’m a little hesitant to put dmso there… is this okay? any better ideas?
thank you!

It’s likely an allergy to something in turnout - weed, fungus on the plants, etc. that he is either ingesting our just touching. Keep doing at least desitin to protect the blisters from the sun. If you mix up an ointment, I’d leave out the DMSO.

See if you can mow the pasture or switch to a different field too.

Try panalog ointment, or 1% triamcinalone ointment (that’s the steroid ingredient and strength in panalog). Both are prescription items.

I’ve just used straight extra strength Desitin on mine. It is hard to rub off, so it stays put, and works well.

Equiderma