Rash

A rash was a symptom of eczema suggested by Elton Pope. (TV: Love & Monsters)

The Thirteenth Doctor obtained synthetic intelligent collagen from Titan to cure Graham O'Brien's rash. (PROSE: Combat Magicks)

Information from invalid sources
Upon hearing of the Doctor's main alias, a human identifying himself as one of the UB60,000,000 mentioned a "really nasty rash" on his back in the hopes that he could help. (NOTVALID: Untitled)