Glurnin

A strange skin disease causing peoples skin to begin to turn gray and become hairy and thick has come about in the world of Karenth. Its origin is unknown, but it appears to be mildy contagious, but many people are immune to it. Others are highly affected.
The term Glurnin comes from the orc word for the disease. However, the orcs have refused to share the cure for the disease with the Displaced due to the constant war between the groups.
The disease usually affects a small part of the body, often in exposed areas, but in a handful of people it has spread throughout the body. It often affects halflings, and rarely the remaining races, but never affects the fey.
The disease has existed almost since the time the Displaced arrived in Karenth.
Adventurers have noted that the orc and goblin populations are immune to the disease and there are even rumors that the orcs created a cure for the malidy.

The Real Story

The disease is a plague unleashed by the Displaced when they first began to explore the castle near modern day Ironholm. When they were exploring the castle, one of the rooms they broke into was infested with a fungus which is the cause of the disease. It had been entombed by the Nethen in that room in the hopes it would never be released.
The orcs and goblins have been aware of a rare natural fungus for millenia, and as such created a cure for the disease long ago.
Strangely, the Living Stone People are highly affected by the disease, and even the orc cure fails to work on them. In the cases where the living stone people (LSP) get the disease, their entire body will be covered with long thick hair.