My Scrotum Also Called Balls Or Testicle Skin Was Reddish

My scrotum also called balls or testicle skin was reddish black and moist on the upper left side of the scrotum by the left thigh nothing on my penis i washed it with soap yesterday and put a little hydrocortisone cream in it the skin came of in some of the areas only slightly leaving slight abrasions its only been 1 day and it looks alot better could this be heat rash i didnt have unprotected aex with anyone with sores the nurse said she thinks its a heat rash can a heat rash do that! Just confirming that