sacs.The damp skin is an ideal site for fungi to multiply.Also wear cotton underwears and change them twice a day and do not share other people’s towels.Application of local antifungal cream(terbinafine, clotrimazole, econazole, ketoconazole, miconazole) and oral antifungal drugs are the mainstay of treatment.
If the symptoms persist then pls get it evaluated from a dermatologist.
Hope it helps .Take care and pls do keep us posted in case you have any additional queries.Kind regards.