Most fungal infections are likely to become severe only in patients who are immunocompromised in some way, as in the case of the AIDS patient in the last photo. But if the immune system defenses are down, then a fungus can wreak truly gruesom havoc on the body, as these photos demonstrate.

For additional information (and some wince-worthy photos) of fungal infections in human and non-human animals and plants, visit Doctor Fungus.

You'll never go outdoors again.