Finger Infection Causes

Bacteria cause most of these finger infections. The exception to this is the herpetic whitlow, which is caused by a virus. How the infection starts and is found in a particular location is what makes each specific type of infection unique. Usually some form of trauma is the initial event. This may be a cut, animal bite, or puncture wound.

• Paronychia: The offending bacteria are usually staphylococcal and streptococcal organisms. Rarely, a fungus causes this infection, which usually begins as a hangnail. Often a person will attempt to bite off the piece of nail that is at the corner. This results in an open wound that allows the bacteria found on the skin and the bacteria found in the mouth to infect the wound. The infection can then spread to the surrounding tissue next to the nail and cuticle.

• Felon: This bacterial infection of the finger pad, caused by the same organisms that cause paronychia, is usually the result of a puncture wound. The wound allows the introduction of bacteria deep into the fingertip pad. Because the fingertip has multiple compartments, the infection is contained in this area.

• Herpetic whitlow: The offending viral organism is the herpes simplex virus type I or II. This is the same virus that causes oral or genital herpes infections. People in certain occupations are more at risk for this infection. These include dentists, hygienists, physicians, nurses, or any other person who may have contact with saliva or body fluids that contain the virus. People with oral or genital herpes may also infect their own fingers.

• Cellulitis: The most common causes of this bacterial infection are staphylococcal and streptococcal organisms. This infection is usually the result of an open wound that allows the bacteria to infect the local skin and tissue. The infection can also spread to the hand and fingers by bloodflow carrying the organisms.

• Flexor tenosynovitis: This bacterial infection is usually the result of penetrating trauma that introduces bacteria into the deep structures and tendon sheaths, which allows the spread along the tendon and associated sheath.

• Deep space infection: This bacterial infection is usually the result of a puncture wound or deep cut that introduces the bacteria to the deep tissue. The collar button abscess is associated with the web space between the fingers. The deep structures of the hand create many potential compartments for this infection to invade.