Necrotizing infections:
Bacteria spread along the fascial layer, resulting in the death of soft tissues, which is in part due to the extensive blood vessel thrombosis that occurs. An inciting event is not always identified. Immunocompromised patients and those who abuse drugs or alcohol are at greater risk, with intravenous drug users having the highest increased risk. The infection can by mono- or polymicrobial, with group A P-hemolytic Streptococcus being the most common pathogen, followed by a-hemolytic Streptococcus, Staphylococcus aureus, and anaerobes. Prompt clinical diagnosis and treatment are the most important factors for salvaging limbs and saving life. Patients will present with pain out of proportion with findings. Appearance of skin may range from normal to erythematous or maroon with edema, induration, and blistering. Crepitus may occur if a gas-forming organism is involved. "Dirty dishwater fluid" may be encountered as a scant grayish fluid, but often there is little to no discharge. There may be no appreciable leukocytosis. The infection can progress rapidly and can lead to septic shock and disseminated intravascular coagulation. Radiographs may reveal gas formation, but they must not delay emergent debridement once the diagnosis is suspected. Intravenous antibiotics should be started immediately to cover gram-positive, gram-negative, and anaerobic bacteria. Patients will require multiple debridements, and the spread of infection is normally wider than expected based on initial assessment. Necrotizing myositis, or myonecrosis, is usually caused by Clostridium perfringens due to heavily contaminated wounds. Unlike necrotizing fasciitis, muscle is universally involved and found to be necrotic. Treatment includes emergent debridement of all necrotic tissue along with empirical intravenous antibiotics.
The majority of acute cases of infections flexor tenosynovitis (FTS) are due to:
Flexor tenosynovitis (FTS) is a severe pathophysiologic state causing disruption of normal flexor tendon function in the hand. A variety of etiologies are responsible for this process. Most acute cases of FTS are due to purulent infection. FTS also can occur secondary to chronic inflammation as a result of diabetes, rheumatoid arthritis, crystalline deposition, overuse syndromes, amyloidosis, psoriatic arthritis, systemic lupus erythematosus, and sarcoidosis.
The most common soft tissue tumor of the wrist is:
Ganglion cyst is the most common soft tissue tumor of the hand and wrist, comprising 50 to 70% of all soft tissue tumors in this region. They can occur at any age but are most common in the second to fourth decades with a slight predilection toward females.
All hand infections EXCEPT the following require surgical management:
All hand infections other than cellulitis will require surgical management. Clinical examination, particularly noting the area of greatest tenderness and/or inflammation, is the single most useful diagnostic tool to localize any purulence requiring drainage. Specific recommendations for differentiating among the possible locations of hand infection are included in the diagnostic algorithm shown in Fig. below.
Diagnostic algorithm. Diagnostic workup for a patient with hand inflammation to evaluate for infection. See text for details a bout particular infectious diagnoses. Abx = antibiotics; exam = examination; FTS = flexor tenosynovitis; IFMC = i ndex finger metacarpal; IV = intravenous; MRI = magnetic resonance imaging; SF MC = small finger metacarpal.
Which of the following patient groups has a 1000-fold increased risk of developing squamous cell carcinoma (SCC)?
SCC is the most common primary malignant tumor of the hand, accounting for 75 to 90% of all malignancies of the hand. Eleven percent of all cutaneous SCC occurs in the hand. It is the most common malignancy of the nail bed. Risk factors include sun exposure, radiation exposure, chronic ulcers, immunosuppression, xeroderma pigmentosa, and actinic keratosis. Marjolin's ulcers represent malignant degeneration of old burn or traumatic wounds into an sec and are a more aggressive type. Transplant patients on immunosuppression have a fourfold increased risk and patients with xeroderma pigmentosa have a 1000-fold increased risk of developing an SCC. They often develop as small, firm nodules or plaques with indistinct margins and surface irregularities ranging from smooth to verruciform or ulcerated (Fig. below). They are locally invasive, with 2 to 5% lymph node involvement. Metastasis rates of up to 20% have been reported in radiation or burn wounds. Standard treatment is excision with 0.5- to 1.0-cm margins. Other treatment options include curettage and electrodessication, cryotherapy, and radiotherapy.
Squamous cell carcinoma involving the nail fold and nail bed. Note the wart-like and ulcerated appearance.
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