You can treat it with Monistat-7 antifungal cream.
You can get this from the pharmacy without a prescription.
Additional measures that will help:
You can also do a Sitz bath daily to soothe the area. It is done using a shallow tub with lukewarm water, with some Epsom salts added. 15 minutes twice a day.
Instructions on how to do Sitz baths:
It's always a good idea to restore the normal good vaginal bacteria, by using natural probiotics. Active culture yogurt is an excellent source, or you can use a commercial product, like Rephresh.
The skin can also be irritated by cosmetic products, like perfumed douches, soaps, washes, etc, and they can also alter the normal bacteria and acidic vaginal pH, so should be avoided.
Tampons should be avoided for the same reasons.
Underwear should be well-ventilated, cotton. Avoid synthetics.
Keep the area as dry as possible, and change any liners every 5 hours. They should be cotton-based.
These measures are going to be as important as the treatment with Monistat, as they will prevent recurrences.
I hope this helps?
Please let me know if you have any questions about this.