Pathology + Treatment
Infections about the wrist are diseases caused by micro-organisms that invade tissue and cause destruction with the consequent loss of function.
An infection can be seeded by a direct penetrating trauma to the skin as simple as an inadvertent scratch with dirty finger nails, or by organisms traveling through the blood stream from another site of infection.
Subdividing Infections
- Superficial and deep
- Localized and diffuse
- Fluctuant – Soft center
- Indurated – Firm consistency
Infections are progressive and aggressive. If the infection process is not interrupted in time, destruction of the local tissues ensues and risks a person’s life. Infection is deadly, with damage advancing quickly. Progression can be measured in hours or days.
The severity of the infection depends on the aggressiveness of the micro-organism and the patient’s ability to mount an appropriate immune system defense response against the infection. In general, patients with diabetes, cancer, HIV, Hepatitis, those receiving chemotherapy or other immunosuppressant drugs cannot mount a normal defensive response against infections and at a higher risk for the infection getting out of control.
Infections are classified as acute or chronic. Chronic infections are indolent and have a more prolonged course. They often present with less obvious clinical symptoms. Organisms causing chronic infections include mycobacteria and fungi. Acute infections are more easily recognized and symptoms present more rapidly.
The classic cardinal signs of infection include:
- Pain
- Redness
- Warmth
- Swelling
- Red streaking up the forearm or shoulder called lymphangitis or cellulitis
- Cellulitis is a superficial infection in the subcutaneous tissue. It can be treated in the early phases with warm compresses, oral antibiotics, hand elevation and initial immobilization.
Patients also experience systemic signs of infection if the infection is more serious and not contained.
Systemic Signs of Infection
- Fever
- Chills
- Generalized discomfort (malaise)
- Nausea
- Weakness
- Mental status changes of dizziness and confusion
Admission to the hospital will depend on the severity of the infection which is demonstrated by the systemic symptoms described above and how rapidly the infection is spreading.
Localized infections begin with pain and induration which subsequently becomes fluctuant, forming an abscess where a pocket of pus develops.
Once an abscess develops, prompt surgical decompression and debridement is performed as antibiotics alone will not resolve the problem. Sometimes the patient may require several trips to the operating room for repeat debridement if significant tissue necrosis is present. Appropriate debridement combined with the correct antibiotics should resolve most cases.
During the procedure, your ROC surgeon will obtain cultures from the infected tissue to identify the infecting organism for selection of the appropriate antibiotic regimen.
Antibiotic treatment is often withheld in chronic infections, loculated infections, or infections associated with an implant, until cultures are obtained. This is to avoid the antibiotic falsely producing a negative culture result, which makes choosing optimal antibiotics difficult.
The most frequent organism causing an infection is usually skin flora in Staphylococcus Aureus and Streptococcus being the most common organisms. The organism’s susceptibility to antibiotic treatment has changed over the years. Resistant strains have emerged, commonly known as MRSA (Methicillin Resistant Staphylococcus Aureus). Careful selection of final antibiotic treatment is critical and consultation with an Infectious Disease specialist may be required.
Joint infections are emergencies. If left to brew, they quickly destroy the joint articular surface, resulting in infectious arthritis.
When a joint infection is suspected, joint x-rays and aspiration of the joint for a culture, or crystal identification, assists in making the diagnosis. Early diagnosis and treatment is critical for a successful outcome.
Conditions that Closely Mimic Infections
- Gout
- Pseudo-gout
- Other crystalline deposition diseases
This is why crystal identification is important when an aspirate is obtained. These crystalline conditions are not infections but present identically to an infection. They also may require surgical treatment in the form of a careful debridement to avoid joint destruction.
A special consideration should be made for a very aggressive form of infection named Necrotizing Fasciitis. Necrotizing Fasciitis is a rapidly advancing infection within the fascial planes. It is characterized by quick destruction of tissues with or without cellulitis spreading within hours. It is also associated with severe generalized symptoms caused by the micro-organism and the toxins it produces. Necrotizing fasciitis is more frequently seen in immunocompromised patients.
Symptoms of Necrotizing Fasciitis
Initially:
- Localized pain
- Minimal swelling
- Induration
- Redness followed by lymphangitis (red streaking)
Progressively:
- Decreased motion with worsening of current symptoms
- Severe tenderness
- Fever
- Chills
- Blistering and peeling of skin
- Tissue crepitance (a crunchy feeling under the skin) may be present when the infective organism forms gas
Multi-organ failure follows with a condition called “disseminated intravascular coagulation,” where the entire blood clotting mechanism is out of control.
If Necrotizing Fasciitis is treated inappropriately, or if treatment is delayed after a diagnosis is made, the results may be fatal to the patient.
A high index of suspicion and experience at recognizing this potentially lethal condition is critical for a successful outcome. Your ROC surgeon should be immediately contacted if this condition is suspected.
The hallmark of treatment is radical surgical removal of infected tissue and the endotoxins at the site of entry and sometimes an amputation is necessary to save the patient’s life.