I got a friction burn/scratch on the head of my penis after morning erection rubbed against boxers. it does not seem to heal and there is no itching. ?

Balanitis: Friction rub unlikely. Balanitis is term for inflammation of head of penis: infectious and non-infectious causes. Infectious include std (herpes) and yeast (common in diabetics and uncircumcised). Non-infectious include eczema, fixed drug eruption, dermatitis (allergic, irritant), or other type of skin lesion. If std unlikely and persists, can see md for DX or trial of otc 1% Hydrocortisone cream.