Soft-Tissue and Hand Infections


Chapter 21

Soft-Tissue and Hand Infections



Bites



1. Human bites


Generally polymicrobial: Staphylococcus aureus, Streptococcus, Corynebacterium, Eikenella corrodens, and anaerobics


Eikenella species unique to human bites


Treat with penicillin including ampicillin and amoxicillin


Eikenella species are resistant to clindamycin.


Note that fight bites require operative exploration and washout because bacteria can be inoculated into joint spaces and spread proximally by extensor tendon motion.


2. Dog bites


Immediately irrigate wounds with saline and wash with soap and/or Betadine


Leave puncture wounds open to heal by secondary intent.


Lacerations can be repaired after copious irrigation if wound appears clean.


Penicillin antibiotics most commonly used


Must be concerned about rabies


If a known animal, it should be quarantined for at least 10 days.


If an unknown animal, rabies prophylaxis is indicated.


Rabies prophylaxis


If prior vaccination: Wash wound thoroughly and provide booster vaccine.


If no prior vaccination: Wash wound thoroughly, administer rabies vaccine and rabies immunoglobulin.


3. Cat bites


Cat bites tend to result in puncture wounds that can seal quickly; therefore, incision and drainage is recommended.


High rate of infection from cat bites


Many infections are polymicrobial; however, Pasteurella multocida is unique to cat bites.


Pasteurella is resistant to cephalexin and cefazolin.


Treat with amoxicillin-clavulanate or fluoroquinolone and clindamycin for penicillin-allergic patients.


Preferred treatment for pediatric patients is trimethoprim-sulfamethoxazole (Bactrim) and clindamycin.


4. Snake bites


The majority of snakebites are from pit vipers.


Treat with immediate immobilization to prevent spread of venom, tetanus prophylaxis, broad-spectrum antibiotics, and observation for venom inoculation (worsening edema, pain, ecchymosis, altered mental status, coagulopathy, compartment syndrome).


Antivenin is indicated for progressive injury or symptoms.


If nonurgent, skin test first for hypersensitivity reaction is preferred.


Avoid debridement and/or tourniquet application


5. Spider bites


Brown recluse spider


Venom inoculation causes a dermonecrotic reaction: Blistering, ischemia, ulceration at the bite site.


Treat with Dapsone.


Watch for hematologic side effects.


Black widow spider


Venom is a neurotoxin that causes severe muscle pain and cramping. Late findings include abdominal pain, tremors, emesis, excessive salivation, and shock.


Treat with calcium gluconate and benzodiazepines (e.g., diazepam).


Spider antivenin can be used in immunocompromised patients.


6. Scorpion stings


Stings are typically self-limiting in adults.


Symptoms include severe localized pain and hyperesthesia and can progress to blurry vision, strabismus, dyspnea, dysphagia, incontinence, fevers, and muscle contraction.


Treat initially with cold compresses and observation.


In children, symptoms can be more severe.


Treat with admission, monitoring, and potentially intubation for airway protection.


Avoid debridement and tourniquet application.


7. Special considerations


Tetanus prophylaxis


If prior vaccination


Tetanus-prone wound (contaminated, etc.): Administer tetanus booster if last dose occurred more than 5 years before new injury.


Non-tetanus-prone wound (clean): Administer tetanus booster if last dose occurred more than 10 years from new injury.


If no prior vaccination


Tetanus immunoglobulin



Necrotizing Soft-Tissue Infections



1. Necrotizing fasciitis: A progressive soft-tissue infection affecting skin, subcutaneous tissue, and fascia and sparing muscle


Extremely high mortality and rapid progression


Can result from minor trauma or hematogenous spread


Most patients have predisposing morbidity, placing them at risk.


Immunocompromised


Diabetes


Renal failure


Substance abuse


Head and neck infections can result from pharyngeal abscesses, tonsillar abscesses, and dental abscesses.


Requires emergent debridement of all devitalized tissue


2. Classification


Type 1 (75% of cases): Polymicrobial, mixed aerobic and anaerobic infections (non-group-A Streptococcus)


Treat with ampicillin-sulbactam, clindamycin, ciprofloxacin, or gentamicin.


Type 2: Monomicrobial, group-A Streptococcus (Streptococcus pyogenes)


Treat with clindamycin and penicillin.


3. Progression of infection


Initial cellulitis stage: Tenderness, erythema, edema, warm skin, fever


May have increased white blood cells (WBCs), thrombocytopenia, hyperkalemia


Cellulitis progresses to ischemia with severe pain, crepitus, and bullae formation.


Final stage characterized by frank necrosis, anesthesia, and “dishwater” drainage.


4. Principles of management


Fluid resuscitation


Intravenous antibiotics


Emergent surgical debridement


Include fasciotomies in setting of compartment syndrome.


Many require multiple trips to the operating room for serial debridement.


Hyperbaric oxygen is indicated as an adjunct to surgical debridement for patients with persistent or extensive necrosis.


Negative pressure wound therapy (NPWT) is often used as a bridge to reconstruction after debridement.


5. Fournier’s gangrene


A necrotizing soft-tissue infection of the perineum


Risk factors: Diabetes, alcoholism, smoking, leukemia, immunocompromised


Rapid progression and high mortality


Treat as above and include antibiotic coverage for anaerobic clostridium species.



Other Common Soft-Tissue Infections



1. Methicillin-resistant Staphylococcus aureus (MRSA)


Increasingly common flora, especially in the nares


More virulent and resistant to penicillins and cephalosporins


Suspect in patient with persistent infection in setting of penicillin antibiotic treatment.


Treat with vancomycin, linezolid, trimethoprim-sulfamethoxazole (Bactrim), or clindamycin.


Nasal mupirocin (Bactroban) can be used to decolonize patients who are noted to be carriers by nasal culture.


2. Orbital cellulitis


Signs


Edema of the upper and lower eyelids


Erythema and cellulitis in the periorbital region


Proptosis


Pain with globe movement


Diagnosis: Computed tomography (CT) scan


Treatment: Broad-spectrum intravenous antibiotics and operative drainage


3. Purpura fulminans


Signs: Acute onset of hemorrhagic bullae formation, desquamation, bilateral symmetric gangrene, and shock


Rapid progression, with high mortality


Most common pathogens are Neisseria meningitides and MRSA


Typically involves pediatric patients


Treatment: Supportive care, broad-spectrum intravenous antibiotics, and activated protein C


Delay surgery until demarcation occurs, except in the setting of acute wound infection or compartment syndrome.


4. Hidradenitis suppurativa


A defect of the follicular epithelium causing follicle occlusion, rupture, and formation of abscesses and sinus tracts, which leads to chronic apocrine gland inflammation and secondary bacterial infections


Commonly affects hair-bearing regions with apocrine glands and skin folds (e.g., axilla, groin, perineum).


Most common pathogens are Staphylococcus aureus and Streptococcus viridans.


Treatment: Antibiotics and incision and drainage of acute abscesses followed by wide excision of all involved skin and sinus tracts with healing by secondary intent or grafting


5. Toxic shock syndrome


Signs: Fever, hypotension, diffuse macular rash, and desquamation of the palms and soles 2 weeks after onset of symptoms


Can occur after surgery, trauma, or retained foreign bodies (e.g., nasal packing, tampons, etc.)


Most common pathogens are Staphylococcus aureus and group-A Streptococcus pyogenes.


Streptococcal toxic shock syndrome characterized by severe disproportionate pain, with potential progression to coagulopathy and organ failure


Treatment: Supportive care and antibiotics


6. Wound infections


Can develop after surgery, trauma, injury


Risk factors can include host (diabetes, malnutrition, obesity, ischemia, steroid use, immunosuppression), wound (presence of nonviable tissue, foreign bodies, contamination), and procedural (length of operation) characteristics.


Of the wound factors, contamination portends the highest risk.


Treatment: Drainage and/or debridement, antibiotics, supportive care

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Sep 2, 2016 | Posted by in Aesthetic plastic surgery | Comments Off on Soft-Tissue and Hand Infections

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