Necrotizing Fasciitis

Definition

Necrotizing Fasciitis is an inflammation of the connective tissue, which may be caused by streptococcal or other types of infection, an injury, or an autoimmune reaction.

Description

Necrotizing fasciitis is a severe infection that leads to necrosis of the subcutaneous tissue and adjacent fascia. The usual cause is a mixture of aerobic and anaerobic organisms, although group A streptococcus alone may be responsible. The organisms reach the subcutaneous tissue by extension from a contiguous infection or trauma to the area, includings surgery. There is widespread damage to the surrounding tissue, and occlusion of small subcutaneous vessels leads to dermal gangrene.

Extensive surgical incision and debridement is the mainstay of treatment, with concomitant antibiotic therapy. There are various other necrotizing conditions that are clinically very difficult to distinguish from one another and from necrotizing fasciitis.

Causes and Risk Factors

This disease is caused by one or more aggressively multiplying bacterial species, most often group A strep. It usually occurs in someone with some kind of underlying illness or severe injury.

Symptoms

There are four principal symptom categories associated with invasive strep infections. These are:

• Fever with shock and light-headedness

• Fever with a sunburn rash

• Fever with a cough and difficulty breathing

• Fever with cellulitis that can progress to necrotizing fasciitis or myositis

The classic warning signals are unusually severe pain at the site of a wound or cut, or in the lymph nodes, and flu-like symptoms, surfacing a few hours after an injury or surgical operation. Common sense dictates that wounds and cuts be well cleansed, kept scrupulously clean, disinfected, and bandaged.

Minor wounds are best cleaned with soap and water, avoiding creams and ointments. Dressings put on wounds should be sterile and act as a filter - keeping out bacteria but allowing air to reach the wound. If sweat cannot evaporate and the cut stays moist, infection easily sets in.

Diagnosis

This problem is diagnosed both clinically by an experienced clinician, based upon the rapid and severe progression of an infection, and by culturing the offending bacteria.

Treatment

Treatment of necrotizing fasciitis is most effective if the infection is recognized in time. Antibiotics and surgical removal of dead tissue are required. If the tissue destruction is widespread, extensive surgery or amputation might be the only way to prevent death.

While early diagnosis and treatment are the key to preventing devastating tissue destruction, physicians and patients often fail to recognize necrotizing fasciitis and its severity.

Being rare, and with an onset that resembles flu-like symptoms, it is often missed until the infection has advanced. One alerting sign is unusually severe pain - far greater than normal for a cut or wound - and painful lymph nodes. For example, a cut on the toe or a surgical leg wound, followed some hours later by severe pain either in the toe, leg, or in the groin (as the infection travels to the lymph nodes), can warn of this potentially deadly, fast-spreading infection.

Questions to Ask Your Doctor

Is it a streptococcal infection?

What is the probable cause?

Will you prescribe antibiotics?

Is surgical removal of any skin or tissue necessary?

Is a dressing required?

How can streptococcal infections be avoided?