Subcutaneous pyogenic infection of the pulp space compartments of the distal finger
Do not mistake for pulp erythema due to paronychia or herpetic whitlow
Infection typically begins with minor trauma to dermis overlying finger pad (e.g. foreign body such as a splinter)
May spread to flexor tendon sheath, IP joint, or underlying periosteum
May spread to flexor tendon sheath, IP joint, or underlying periosteum
The perinychium includes the nail, the nailbed, and the surrounding tissue.
The paronychia is the lateral nail folds
The hyponychium is the palmar surface skin distal to the nail.
The lunula is that white semi-moon shaped proximal portion of the nail.
The sterile matrix is deep to the nail, adheres to it and is distal to the lunule.
The germinal portion is proximal to the matrix and is responsible for nail growth.
Felon
Bed bugs
Bougie
Closed fist infection 
Stye 
Digital Mixoid Cyst 
Chilblains
Hand cellulitis