The Dreaded Lurgi

Came home this rainy evening to a distinctly unwell feeling. Crawling into Caroline's arms for comfort after a particularly disgusting Thai take-out I leaned forward for a kiss and encountered a turned cheek.

"You've got the Lurgi", she said.

"Huh?"

What follows is an explanation ripped from the pages of Wikipedia, or Wikipaedia as they might spell it here:

The lurgy (also spelled lurgi) is British English slang for an unspecified or mythical contagious disease, generally one considered inconvenient and non-fatal with obvious symptoms, such as influenza or the common cold. Phrases like "I've got the lurgi" are commonly heard when somebody is explaining why they cannot attend a social occasion, come to work, etc. It is also often referred to as "The Dreaded Lurgi", based on a Goon Show episode of 1954.

The term is also used in the context of playground games, where lurgi is often used as a phantom contagion or unclean quality, in a manner similar to the North American concept of cooties. For example, "You can't play with us, you've got the lurgi!" could be used when excluding another child from a group.

Etymology
There is some suggestion that it is a corruption and contraction of the word "allergy". This is not supported by the use of the hard 'g' in Lurgy (rhyming with Fergie), as allergy has a softer 'g' sound.

There is also the theory that it is based on the Northern English dialectic phrase "fever-lurgy" meaning lazy or idle.

Another possible origin of the word, and certainly the reason it has become widespread in British culture, can be found in the 1950s BBC radio programme, The Goon Show.

In a 1954 programme of The Goon Show, "Lurgi Strikes Britain", Ned Seagoon must deal with a national outbreak of a highly dangerous, highly infectious and — as it turns out — highly fictitious disease known as the Dreaded Lurgie.[1] It eventually becomes apparent that the disease is merely a convoluted ruse perpetrated by the arch-criminals Count Moriarty and Hercules Grytpype-Thynne in order to sell large numbers of brass band instruments, the playing of which is claimed to be the only cure. In the show, the symptoms of lurgi manifested as an uncontrollable urge to shout "EEEE-YACKABOO!" without realising. It was implied that the disease was fatal; Moriarty claims that the British Isles could be wiped out in as little as six weeks.

References
^ Quinion, Michael. The Dreaded Lurgi. World Wide Words.
Retrieved from "http://en.wikipedia.org/wiki/Lurgy"