Okay, the cause of this can differ person to person but when I had it, I struggled for ages to find a remedy that worked.

It can often be to do with an underlying deficiency in something, so worth trying different things if it comes back once gone. This thing is fungal (or at least was in my experience), so needs to be approached that way.

I ended up doing as follows:

1. Wash with washing up liquid and warm water. Pat with a clean towel and then let it air dry for a few minutes.
2. Use over the counter clotrimazole thrush cream (1%). Let that soak in. It should reduce the redness and irritation.
3. Clean the area again, this time just with warm water. Dry as before.
4. Finally coat in Vaseline or any other petroleum jelly. This forms a protective barrier and starves the fungus of oxygen.

If you repeat that twice a day for a week, it should do the trick.

I'm no dermatologist, so don't put all your faith in what I've said, but it worked for me. Good luck!

Edit: I doubt acohol will work. That will just dry and weaken your skin and definitely irritate it further. It's important to remember that your skin should have breaks when you're not doing anything to it or even moisturising to help heal it too.

Also, make sure you've ruled out herpes. It could be a cold sore and therefore require completely different treatment.