Hello. Thank you for writing to us at healthcaremagic I will suggest a possibility of Tinea Cruris/Fungal Infection of the groins. The location of the rash goes in favor of fungal infection; fungal infections being specially common in the body folds. The fungal growth is favored by occlusion and warmth. Being overweight does add to the predisposition. Chaffing and itching are part of fungal infections. A KOH wet preparation made from a small amount of scale scraped from the surface to look for fungal elements would be confirmatory. If I was the treating doctor I would suggest an OTC topical antifungal e.g clotrimazole 1% cream Or one of the prescription antifungals e.g sertaconazole, luliconazole or bifonazole. Since the involvement seems to be quite extensive therefore I am also in favour of Oral antifungals in addition to the topical antifungals. Oral antifungals are faster acting and any one of either fuconazole , terbinafine or itraconazole may be started. Oral as well as topical treatment should be continued for at least 4- weeks. An OTC oral antihistamine e.g cetrizine 10 mg once daily will provide you symptomatic relief from itching. Once the symptoms resolve, an antifungal dusting powder e.g clotrimazole dusting powder would prevent a recurrence by keeping the folds dry therefore inhibitory to fungal growth. Regards