In House of the Dragon, it was revealed that King Viserys Targaryen has a skin disease that "refuses to heal." I'm wondering if it's one of the fictional diseases in the A Song of Ice and Fire series, or if it's a real-life disease.
Viserys: Is it healing?
Grand Maester Mellos: It has grown slightly, Your Grace.
Viserys: Can you say yet what it is?
Young maester: We've sent inquiries to the Citadel. They are searching the texts for similar cases.
Viserys: It's a small cut from sitting the throne. It's nothing.
Mellos: The King has been under heavy stresses preparing for the birth. Bad humors of the mind can adversely affect the body.
Otto Hightower: Whatever it is, it needs to be kept quiet.
Mellos: We should leech it again, maester.
Young maester: It's a wound that refuses to heal, Grand Maester. Might I suggest cauterization?
Mellos: Cauterization would be a wise course of treatment, Your Grace.
- House of the Dragon S01E01 "The Heirs of the Dragon"
Viserys' wound looks like a skin ulcer. Viserys would later get another cut, on his finger, from the iron throne. In episode 2, the maesters attempt to treat the wound with maggots.
Grand Maester Mellos: This is our best chance to save the digit, Your Grace. The maggots will remove the dead flesh and hopefully stop the advance of the rot.
- House of the Dragon S01E02 "The Rogue Prince"
Normally, cuts should heal over time and not grow, without the need for cauterization or having maggots eat the dead flesh. It seems that Viserys has a serious disease aggravating his wounds. What is the nature of King Viserys Targaryen's skin disease?