I think there are only two ways of a possible reason of getting gangrene on the foreskin which 1 . paraphimosis improper treatment which gangrene could hapen on the foreskin and the glans besides . Paraphimosis can be easily taken care of but many doctors believe circ is the answer for paraphimosis which it isn't . Paraphimosis can be treated manual if the 'swelling isn't too much yet', otherwise sugar injection shot to reduce swelling . Paraphimosis can be prevented avoid forced retraction especially during a catheter time because some nurses /professionals forget that a intact male is intact meaning forgetting to cover him back up so the person gets what you call iagoteneric(sp) doctor caused paraphimosis .
The reason why paraphimosis if not treated can lead to gangrene of the penis which includes foreskin and glans is because when the foreskin is trapped behind the glans it cuts off the circulation so I imagine the gangrene would proably hit the glans of the penis first before it hit the foreskin but I'm not totally sure.
The other thing is there could be gangrene on one part of the body that can lead to other part of the body . my great great grandpa he died from gangrene so gangrene can cause death .
Fournier's gangrene, sometimes called Fournier's disease, is a bacterial infection of the skin that affects the genitals and perineum (i.e., area between the scrotum and anus in men and between the vulva and anus in women). The disease develops after a wound or abrasion becomes infected.
I also imagine since some diabetics get gangrene on their feet/legs that they may end up possibly getting gangrene on other parts of their body besides but I think the legs/feet are more likely first than the genitila part .
Very rare to get gangrene from a burn or an insect bite