In the early 90’s a new street drug started it’s journey from the west coast of North America to the east. Many rave going young people tried the new drug and became hopelessly addicted. The drugs destructive effects are visible in the photos here. The outward effect is only half the story as the drug destroys mental function. The reason for the open sores that appear on the face are due to the user having the feeling that something is crawling on their skin. They begin by scratching at the hallucinations and the sores gradually worsen.
You can see more photos and read more here