Infections of the hand require urgent medical attention and treatment. These infections spread easily and fast to surrounding structures and complications are common. Loss of finger to severe infection is the most dreaded complication. Even after the infection has resolved, problems can occur that will affect functions of the hand such as stiffness, loss of strength, and even loss of tissues such as skin, nerve and even bone. Thus early and aggressive treatment of hand infections is essential.
When seen early, some infections can be treated with antibiotics. However many infections with delayed treatment may need surgical drainage, and removal of infected tissues.
Felon is a extremely painful, throbbing infection of the finger tip and pulp. Surgical drainage and antibiotics are required. If treatment is delayed, destruction of the soft tissues and skin, as well as the bone can occur.
A paronychia is an infection of the area of the skin around the fingernail. Acute paronychia is caused by bacteria. It presents acutely with redness, swelling and pain. Pus will develop later. Early cases may be treated with soaks and antibiotics. Once pus is suspected, surgical drainage is required. Chronic paronychia is caused by fungus, and the area becomes just mildly red and swollen. Little or no drainage and mild tenderness are typical of this infection. It is common in hands which are frequently wet. It may be treated with fungal medication and elimination of exposure to moisture. Occasionally, surgery is needed to remove infected tissue. Prolonged treatment is common with chronic paronychia.
Herpetic whitlow is a herpes virus infection of the fingers and hand. It is more common among healthcare workers whose hands are exposed to the saliva of patients with herpes virus. It is characterized by presence of small, swollen, painful blood-tinged blisters, and sometimes numbness. Treatment is usually conservative and it typically resolves in several weeks.
Joint infection (Septic arthritis) / Bone infection (osteomyelitis)
A wound in or near a joint can cause an infection of the joint. The joint can be destroyed by the bacteria and inflammation reaction which erode the cartilage surface of the joint. Apart from antibiotics, surgical drainage is required.
Infection of the bone can occur via a spread from the infected joint, wound with exposed bone and from the blood spread. It is difficult to treat and typically requires one or more operations to remove infected tissue as well as weeks of antibiotics.
Tendon sheath infection
This is a potentially dangerous infection. The sheath or covering of the flexor tendon of the fingers gets infection from a small laceration or puncture wound over the finger. Patients will have acute pain along the fingers with stiffness of the finger in a slightly bent posture, diffuse swelling and redness of the finger (sausage-like appearance). This infection requires immediate surgical drainage of the tendon sheath and antibiotics. These infections can have severe complications such as finger stiffness, destruction and rupture of the tendon and destruction of the whole soft tissues of the finger including the blood supply.
Deep space infections
There are few spaces in deep in the hand which can become infected from even from a small puncture wound. There are thespace deep in the thumb area (thenar space), the palm (deep palmar space) or even the web area between the bases of fingers (collar-button or web space abscess). These infections require surgical drainage. Late drainage can result in spread of infection to other areas.
Infections from bite wounds
Infections from human bites or animal bites carry several bacteria and typically require additional antibiotics. Wounds are frequently not closed after treatment so that any infection can drain out. Deep spaces and structures such as joints may be involved. Surgical removal of infected or dead tissue is often required. Rabies infection from an infected animal may be serious, even fatal.
Atypical mycobacterial infections
These are rare infections of the tendon lining caused by rare bacteria, “atypical mycobacterium.” These develop gradually (not acutely). Patients may have minimal synptoms such as swelling and stiffness without much pain or redness. Treatment requires special combination of several antibiotics for several months. Surgical removal of the infected lining of the tendons may also be necessary. These infections may involve other soft tissues as well. Mycobacterium marinum is a common form and typically develops after puncture wounds from fish spines, or contamination of a simple wound or abrasion from stagnant water (in nature or from aquariums). Patients with impaired immune systems (AIDS patients, cancer patients, patients with long term steroid treatment) are more susceptible to these infections.