HI you probably are suffering from fungal infection
of skin called tenia corporis.keep your body dry avoid humidity as much as possible.
you should apply topically clotrimazole
cream or terbinafin cream daily till clear of rash if it is spreading then you should take oral itraconazole
or terbinafine 250 mg daily for about2 wks.
lotion/shampoo while bathing.