Scorched Plague

The Scorched Plague is caused by a fungus found underground in Appalachia in 2102.

Background
Research logs at Arktos Pharma seems to suggest that the Scorched plague was created by them before the war. Whether it was designed as a disease or accidently created as a byproduct is currently unknown.(source?)

The Scorched Plague is spread by a fungus found underground in Appalachia. It was spread to the surface by scorchbeasts and was influential in creating the Scorched, causing crystalline green growths in the latter.

Appearances
The Scorched Plague appears only in Fallout 76.