Necrotizing fasciitis is present when there is a bacterial infection of the skin, subcutaneous tissue, and muscles. The most common pathogens are group A streptococci, staphylococci, or clostridia. The affected tissue must be completely removed to avoid endangering the patient’s life.
What is necrotizing fasciitis?
Fasciitis is a necrotizing fascia disease. It is an inflammation in fascial tissue in which cells perish. The inflammatory disease is also known as necrotizing fasciitis. The incidence is reported to be up to one case per 100,000 population. The inflammation is bacterial in origin and shows lightning-like rapid progression. The skin and subcutaneous tissue are affected, with involvement of the fasciae. For this reason, the disease is classified as a bacterial soft tissue infection. Among the most important risk factors are circulatory disorders, as can occur in the context of higher-level metabolic diseases. Depending on the species of the bacterial pathogen, two subgroups of nacrotizing fasciitis are distinguished. These subgroups are referred to as type I and type II of the disease and may show different courses. In immunodeficient patients, the course of infection is generally more severe. If the bacteria involved reach the bloodstream of these patients, the risk of sepsis or septic shock is high. In a sequel, necrotizing fasciitis can mature into a life-threatening condition for immunodeficient patients.
Causes
People with circulatory disorders in peripheral vessels are most commonly affected by necrotizing fasciitis. Lymphatic drainage disorders and immunodeficiency also favor the development of the disease. Metabolic patients, especially diabetics, are particularly at risk. As a rule, the infection is triggered by skin injuries or abscesses of the skin, which give bacteria access to the subcutis. Intramuscular injections such as therapeutic injections for diabetes or therapeutic surgical procedures can also open the gates to the subcutis for bacteria. Group A streptococci are considered the most important pathogens of necrotizing fasciitis. Staphylococci or clostridia can also theoretically cause the infection, but are rarely involved in clinical practice. At times, the infection is also a mixed infection:
- For example, necrotizing fasciitis type 1 corresponds to a mixed aerobic-anaerobic infection and occurs primarily after surgical procedures. *Necrotizing fasciitis type 2 is caused by group A streptococci, making it the most common form of infection.
- A special form of necrotizing fasciitis is Fournier’s gangrene in the groin and genital region, which affects men in particular. Neonates with omphalitis have increased susceptibility to necrotizing fasciitis of the umbilical region.
Symptoms, complaints and signs
Patients with necrotizing fasciitis suffer from rather nonspecific symptoms at the beginning of the infection. The initial symptoms include mainly local pain and more or less high fever. In the beginning, these symptoms are often accompanied by chills, fatigue and similar signs of infection. Within the first week, the areas slowly swell up under inflammatory processes. Usually the skin over the infectious focus is discolored bluish-red and becomes bluish-gray in the course. Due to the inflammatory processes in the subcutis, the upper one overheats and often throws confluent blisters. The blisters contain a light to dark red fluid with a viscous consistency. In an advanced stage, the affected tissue necrotizes. The necrosis can be more or less extensive and usually affects not only the soft tissue but also the nerves and muscles. Pain is usually no longer present from this point onwards, as the sensitive nerves in the area die off bit by bit. In most cases, the patient’s fever still rises during these processes. When the pathogens involved reach the bloodstream, immunologically healthy patients experience a temporary bacteremia, which is compensated by the immune system. In immunocompromised patients, the bacteremia may persist and result in sepsis.
Diagnosis and course of the disease
Air pockets in the muscle fascia can be documented by CT in the diagnosis of necrotizing fasciitis. If suspected, microbiologic diagnosis takes place with puncture of the blisters or biopsies. Diagnostically, a Gram’s preparation provides decisive indications. Microbial culture is a standard diagnostic test. Early diagnosis has a positive effect on the prognosis. Because of the rapid progression, mortality is high at 20 to 50 percent if diagnosis is delayed, especially for type II. The prognosis is particularly unfavorable if the trunk is involved.
Complications
In this disease, affected individuals suffer from bacterial infection. In most cases, however, this involves surgical removal of all infected tissue, so complications are thus usually avoided. In this disease, patients suffer from a high fever and further also from fatigue and exhaustion. Pain in the limbs and headaches can also occur and significantly reduce the patient’s quality of life. There is also swelling of the skin and the skin itself usually turns brownish. Furthermore, blisters form on the skin. If the disease is not treated, the nerves die and paralysis or other disturbances of sensibility occur. This nerve damage is usually not reversible and cannot be restored. In severe cases, the disease can also lead to blood poisoning and death of the affected person. As a rule, the disease is treated without complications. With the help of antibiotics, most of the symptoms can be limited relatively well. With an early diagnosis, there is a completely positive course of the disease and no reduction in the life expectancy of the patient.
When should you see a doctor?
Symptoms such as chills, fever, and fatigue always require medical evaluation. If skin changes are added to these complaints, there may be underlying necrotizing fasciitis, which must be diagnosed and treated immediately. Risk groups include people suffering from circulatory disorders, immunodeficiency or lymphatic drainage disorders. Diabetics and patients with abscesses, skin lesions or bacterial infections are also at risk and should have the symptoms described clarified quickly. If the complaints occur in connection with therapeutic injections, the responsible physician must be informed. A physician must be consulted at the latest when visible necrosis occurs as well as associated pain in the limbs or signs of blood poisoning. Affected persons can consult their family doctor or a dermatologist. Depending on the type and severity of necrotizing fasciitis, other specialists may subsequently become involved in treatment. Advanced disease must be treated as an inpatient, with surgical removal of the necrosis. Because of the high risk of infection, any surgical wounds must also be monitored and cared for by specialists.
Treatment and therapy
Treatment of necrotizing fasciitis is surgical. All affected soft tissues must be radically removed as soon as possible. If too little tissue is removed, fasciitis spreads at a high rate and results in high tissue loss or even death. The pathogens that cause the infection are extremely aggressive, so no germs should be left in the tissue during surgery. In most cases, surgical intervention is combined with drug therapy. This therapy consists of three times daily administration of clindamycin, which is often given in combination with penicillin. Many of the pathogens are antibiotic resistant. Therefore, pure antibiotic treatment is usually not effective. When all surgical and drug measures have been exhausted and no improvement has been brought about, the affected limb must be amputated to save the patient’s life.
Outlook and prognosis
Immediate surgical therapy greatly favors the prognosis of patients. Factors such as advanced age of affected individuals, female gender, and concomitant diseases such as diabetes mellitus also influence the prognosis. It has also been shown that necrotizing fasciitis of the trunk of the body is associated with a significantly worse outlook for those affected.Likewise, a significantly increased amputation rate as well as mortality can be mentioned for necrotizing fasciitis, especially after injection therapy. Therefore, knowledge of all these different prognostic conditions should already be the basis for the physician’s quick decision at the time of hospital admission. After surgical therapy, intensive medical complex therapy as well as antibiotic administration are in the foreground for affected patients. Due to surgery, patients may require large amounts of intravenous fluids. Therapy in a high-pressure oxygen chamber is also recommended afterwards. However, the extent to which this is helpful has not been established. If toxic shock syndrome develops during the course of the disease, immunoglobulin is administered. The overall death rate averages 30%. In older patients, as well as in the company of other medical disorders and when the disease is advanced, the prognosis is worse. Delay in diagnosis and treatment, as well as inadequate removal from dead tissue, worsens a prognosis.
Prevention
Because poor circulation and immunodeficiency are considered risk factors for necrotizing fasciitis, immune-enhancing and circulation-enhancing measures can be broadly interpreted as preventive measures.
Follow-up
After surgical removal of necrotizing fasciitis, intensive follow-up of the tissue is very important. Tissue samples taken at regular intervals are used to determine whether bacteria can still be detected. Affected patients are also prescribed antibiotics. One problem, however, is that many bacteria that cause necrotizing fasciitis are resistant to conventional antibiotics. There is a risk that new sores will form and rapidly enlarge. For this reason, in the first days after surgery, various preparations are administered and examined to see if possible bacteria are attacked. If a suitable antibiotic is found, patients are instructed to take the preparation for several weeks. This is the only way to reduce the risk of a recurrence of necrotizing fasciitis. If the disease has already affected organs or limbs, further surgery and therapy may be required to treat the late effects of the disease. Patients with diabetes mellitus are a risk group. Since diabetes significantly increases the incidence of wounds, patients with diabetes mellitus require intensive care. A regular examination by a diabetologist, for example, should rule out the possibility of even small wounds forming. This is to rule out the possibility of bacteria becoming established in the tissue and causing necrotizing fasciitis.
This is what you can do yourself
Necrotizing fasciitis is life-threatening, and affected individuals should never attempt to treat the disorder themselves. However, this does not mean that patients cannot help reduce the risk and mitigate the consequences of the disease’s progression. The sooner fasciitis is recognized as such, the higher the chances that amputation can be avoided. Members of at-risk groups, including in particular diabetics and people with immune deficiencies, should therefore keep a close eye on even minor everyday injuries and recognize the symptoms of fasciitis. Anyone suffering from diabetes who suddenly develops a fever shortly after a minor injury while peeling a potato should not dismiss this as the onset of a cold, but should consult a doctor as a precaution. High-risk patients should also reduce their risk of injury. Minor cuts or abrasions cannot always be avoided. However, the probability of occurrence can be reduced. In particular, protective gloves should always be worn when gardening or performing manual tasks. If an injury does occur, the wound must be cleaned and disinfected immediately. Optimal initial treatment of the wound can reduce the risk of infection and thus also fasciitis. Diabetics can also help strengthen their immune system and improve blood flow to the limbs by eating a healthy diet and exercising regularly. This also reduces the risk of fasciitis.
