Believe it or not, some 20 Mule Team borax will bring instant relief.

Put some in your hand, let it get wet in the shower and rub it in. You'll feel it turned into like water softener and immediately the itching and irritation will go away as it has a high pH level and will kill any bacteria or fungus.

Milk of Magnesia is slightly higher at a pH of 10.5 and works as well. I used it as a remedy for foot itch due to damp boots while hiking and when I told the pharmacist about it they said, "Wow you're pretty smart guy to think of that".