Hello. Thank you for writing to us at healthcaremagic
I suggest a possibility of Fungal Infection/
Tinea cruris. Chaffing and itching are suggestive of fungal infection
Body folds being a common site for fungal infections because they provide an ideal environment for the fungus to proliferate which grows well in moist and warm condition.
A KOH wet preparation made from scraping a small amount of scale from the surface of skin lesions to look for fungal elements would be confirmatory of fungal infection.
If KOH scraping is positive for fungal elements I would suggest you to apply a
topical antifungal.
Either an OTC topical antifungal e.g
clotrimazole 1% cream can be tried or one of the prescription antifungals like
sertaconazole, luliconazole, bifonazole etc. Thye need to be used twice daily for 4 weeks.
An OTC oral antihistamine e.g
cetrizine 10 mg once daily will provide you symptomatic relief from itching.
Regards