Pink inflamed patch like rash that spreads from inner thighs to outer thighs to buttocks & starting down legs. foreskin is inflamed but no rash. some groin pain. itchy. no blisters, no smell, no unusual discharge. penis looks fine. yeast infection?

Probably tinea: Tinea is a type of fungus that commonly causes the rash like you describe, and is less likely to cause an odor than Candida, which causes most vaginal yeast infections. Try applying a small amount of over-the-counter terbinafine cream daily. You cannot "kill" the fungus, the cream "paralyzes" it, and with regular daily use, your body will shed the fungus off your skin.