Rash turned out to be skint yeast infection, took ketonazole & calmposeptine, rash gone but itching persists, do i need more ketonazole cream?

Occasionally: the rash resolves but the infection has not so I would suggest continuing the anti fungal for a few more days after the rash has resolved.

Topical steroid: If the rash has disappeared it is likely that the itching (which is actually subliminal pain) is a residual effect of the yeast infection and a topical steroid may be of assistance.

Could be allergic: Could be an allergy to underwear or laundry detergent put some hydrocortisone cream if it does not resolved go to your doctor. Good Luck.