"It sounds to me as though you may have contracted Dragon Pox"
-- Professor Helbert Spleen (DP3)
A Healer at St. Mungo’s Hospital of Magical Maladies, he also writes for the Daily Prophet (DP3)
Professor Spleen gave advice to wizard Howland Coopey, whose alarming symptoms indicated a possible case of Dragon Pox (which the professor said would go away of its own accord). He also recommended that the sufferer immerse his spark-emitting nose continually into ice-cold water while waiting (DP3)
Other canon notes and references
A cure for Dragon Pox was discovered in the 16th century by a famous healer, Gunhilda of Gorsemoor (FW), but Professor Spleen hasn't mentioned this in his reply, or that there have been deaths from Dragon Pox (HBP9, Pm)
A person's spleen is located in their abdomen, but the word also means spite, ill temper or annoyance. Maybe that is why he gives the wrong advice to Mr Coopey.
While the date printed on DP3 is 1 June 1999, the timeframe for these events is 1992-1993.