The Pox

The is a disease that originated in the green country of Eland Jandry. Symptoms of The Pox include fatigue, dizziness, fever, and a painful rash. In serious, untreated cases the rash can form into painful welps and the fever can cause hallucinations and nightmares. It is most common in elvish and human children, though it is possible to be caught be adults and people of other races. If left untreated, the disease can be deadly.
This is a disease that the Healer's Guild have been battling for a long time. They have limited understanding of the disease and how it spreads. Scientists have been able to learn that it is a virus based on the auras within the patients' bodies they have been able to see. However, they have not been able to find a pattern in the people it afflicts. A sorcerer is sometimes able to fight the disease by manipulating the aura, but since they cannot destroy it, the best they can do is keep it from spreading while the patient's body fights the disease. 
The reason it is so widely feared by citizens of Eland Jandry is because of its association with the fae. Though it is well-known that not all fae are malicious, there is an urban legend about a mysterious fae creature that may be involved with the disease somehow. This theory comes from the common visions and hallucinations sick patients have of a tall, slender creature with long limbs and long antlers portruding from its head. SOme report the creature having glowing eyes, others report the creature having no eyes, but rather a large mouth with sharp teeth. When questioned about it, most fae deny the existence of such a creature, but some choose to stay silent or give vague responses about the possible existence of such a beast. 
Though there are no clear patterns about how one catches teh disease, the superstition has led people to believe that it is caused by the creature targeting the patient. Parents usually keep their children from wandering in the woods by themselves. People also arm themselves and their children the charms made of iron to keep the creature away when they travel.