Whistle-toe!
But seriously, whistle-toe is a nasty affliction. Alongside athlete's foot, tennis elbow and Achilles' heel, whistle-toe is one of the worst impediments to have. It is a fungal infection, commonly caught due to inadequate care of hygiene in communal places, such as swimming pool showers or fountains, and is most notable for (and indeed is named because of) the characteristic whistling a diseased foot will make upon its entry into a woollen sock (and to a lesser extent, the introduction of that woollen sock-clad foot into a leather shoe or boot). It is not very contageous, but extremely difficult to cure. Healing times can take upwards of three months, with one extraordinary case where whistle-toe took seven years to disappear from a poor sufferer's body. Many folk cures exist, including the wearing of pigs' hooves as earrings and the consumption of dried figs crushed with yak's yoghurt; however doctors recommend the wearing of rubber socks (as used by sufferers of verrucas) coated internally with talcum powder and salt. Recent statistics have shown that 1 in every 50,000 adults in the USA suffer from whistle-toe, and that most suffers will not even admit their infection for fear of ridicule.
Have a very merry Christmas.