Sounds like Contact Dermititis, I copy and pasted some info from the web
You call it a
rash. Your doctor calls it
dermatitis. Either way, your
skin gets red and tender after you've touched something.
It could be caused by an
allergy, or because the protective layer of your skin got damaged.
Usually, you won't get a rash the first time your skin touches something you're allergic to. But that touch sensitizes your skin, and you could have a reaction the next time. If you got a rash on first contact, chances are you've touched that trigger before and just didn't know it.
When something is irritating or damaging your skin, you'll probably see a rash right away. With an
allergy, it may be a day or two before the rash shows up.
Symptoms of a contact allergy are usually right around where you touched the thing you're allergic to.
Irritant contact dermatitis (skin damage) tends to burn and be more painful than itchy.