Section 5. Bone, Joint, and Muscle Disorders

Chapter 71. Hand Disorders

Topics: Introduction | Ganglia | Deformities | Carpal Tunnel Syndrome | Cubital Tunnel Syndrome | Radial Tunnel Syndrome | Kienböck's Disease | Shoulder-Hand Syndrome | Injuries | Infections

Infections

Human and animal bites can cause an infection of the hands; some other infections are felon, paronychia, and herpetic whitlow.

Infections Caused By Bites

The most common cause is injury to the knuckles by the teeth from a punch to the mouth. Animal bites are also common causes. Wound contamination by a number of types of bacteria can result from human and animal bites. All bite injuries are potentially dangerous and can cause significant infection. The injured area should be cleaned surgically, with the wound left open. Antibiotics should be given to prevent joint infection (septic arthritis), which can otherwise lead to permanent destruction of the knuckle joints. Bacteria in human and animal bites are resistant to many antibiotics but are generally sensitive to ampicillin and penicillin.

Felon

A felon is infection of the soft tissue (pulp) at the fingertip.

An infection of the fingertip can lead to an abscess, which creates pressure and death of nearby tissues. The fingertip becomes very swollen and firm with intense throbbing pain. The doctor makes the diagnosis by examining the affected finger. If a felon is not treated promptly, the underlying bone, joint, or tendons may become infected. Minor felons may be treated with warm soaks several times a day to increase blood flow. An antibiotic is usually needed. Treatment may require prompt surgical drainage of the abscess as well.

Herpetic Whitlow

Herpetic whitlow is a viral infection of the fingertip.

Herpes simplex virus may cause an intense, painful skin infection. The fingertip is sore and swollen but is not as firm as in a felon. The appearance of tiny fluid-filled blebs (vesicles) on the fingers is diagnostic. A herpetic whitlow is often mistaken for a felon. The disorder eventually goes away on its own. Surgery is not needed.

Paronychia

Paronychia is infection of the cuticle.

This very common hand infection can be caused by an injury to the nail and cuticle, nail biting, or aggressive manipulation of the cuticle during a manicure. Paronychia can be caused by many different bacteria, including Pseudomonas and Proteus. The cuticle and tissue at the margin of the nail become red, swollen, and intensely painful. If left untreated, an abscess will develop and can spread to the fingertip (leading to a felon) or to the bone.

The doctor makes the diagnosis by examining the affected finger. In its earliest stage, paronychia may be treated with oral antibiotics and frequent warm soaks to increase the blood flow. If an abscess develops, it must be surgically drained.

Hand Abscess

A hand abscess is an accumulation of pus affecting the hand, usually caused by a bacterial infection.

Abscesses in the hands are fairly common and usually result from injury. An abscess in the soft pad at the tip of a finger nearly always results from a minor injury, such as a splinter or needle prick. Severe pain, warmth, and redness develop over the abscess, often with swelling of nearby lymph nodes in the arm. Infection of the bone underneath the abscess may cause more pain.

Abscesses may occur around the tendons that run along the inside of the fingers. This type of abscess is caused by an injury that penetrates one of the creases on the palm side of a finger. Infection and pus form around the tendon and rapidly destroy tissue. The gliding mechanism of the tendon becomes damaged, so the finger can barely move. Symptoms include swelling and inflammation of the finger, tenderness over the tendon sheath, and extreme pain when trying to move the finger. Swollen lymph nodes near the abscess are common. Fever is also common.

An abscess may occur in any part of the palm and spread between the metacarpal bones (the hand bones between the wrist and fingers). Such an infection may occur after the skin is ripped or the hand is punctured by something sharp. Palm abscesses (also called collar-button abscesses) may develop from an infected callus. Palm abscesses begin as intense throbbing pain with swelling and severe tenderness to touch.

Treatment involves surgically draining the pus. Laboratory cultures of the pus are carried out to determine which antibiotic is best for treatment (usually a cephalosporin).

Infection of the Tendon Sheath

An infection of the flexor tendon sheath is characterized by pain and swelling, with tenderness along the length of the tendon sheath and pain when straightening the finger. Pus may spread inside the hand to form a horseshoe-shaped abscess. Surgical drainage of the abscess is required. Antibiotic therapy is also required (the choice depending on the results of laboratory cultures of the pus).