whitlow

n. painful abscess on the side of the nail at the end of a finger or toe

The nail disease paronychia (commonly known as felon or whitlow) is an often tender bacterial or fungal infection where the nail and skin meet at the side or the base of a finger or toenail. It can start suddenly (acute paronychia) or gradually (chronic paronychia).
See more at Wikipedia.org...

Whitlow /whit·low/ felon. herpetic whitlow primary herpes simplex infection of the terminal segment of a finger, with extensive tissue [more]Whitlow - Community and Resources

Noun
1. a purulent infection at the end of a finger or toe in the area surrounding the nail
(synonym) felon
(hypernym) infection

(a.)
An inflammatory disease of the feet. It occurs round the hoof, where an acrid matter is collected.
  

(a.)
An inflammation of the fingers or toes, generally of the last phalanx, terminating usually in suppuration. The inflammation may occupy any seat between the skin and the bone, but is usually applied to a felon or inflammation of the periosteal structures of the bone.