Hello. Thank you for writing to us at healthcaremagic Going by your description of the patch and judging from the location of it, I am of the opinion that this is most likely a patch of Fungal Infecton/Tinea cruris. Tinea classically presents as annular or circular patches with raised margins which extend peripherally and central clearing. Fungal infections are common at sites of body folds, specially in hot, humid weather because the anatomy favors fungal growth. You may try an OTC antifungal e.g clotrimazole 1% cream, twice daily for 4-6 weeks. Adding an Oral antifungal would produce faster results. Oral antifungals e.g fluconazole Or terbinafine are prescription products and therefore you need to talk to your doctor for the needful. An OTC oral antihistamine e.g cetrizine 10 mg once daily will provide you symptomatic relief from itching. Regards