Wound Care Algorithm Diagnosis and Treatment: A Comprehensive Guide to Skin and Soft Tissue Infections

I. Impetigo and Ecthyma

1. Evaluation and Diagnosis

• Gram stain and culture: Recommended for pus or exudates to identify Staphylococcus aureus and/or β-hemolytic Streptococcus. However, treatment can proceed without these studies in typical cases.

2. Treatment

• Topical vs. Oral Antimicrobials:
  • Impetigo (bullous and nonbullous): Topical or oral antimicrobials are effective. Oral therapy is preferred for numerous lesions or outbreaks to reduce transmission.
  • Ecthyma: Oral antimicrobials are necessary due to deeper infection.
• Specific Antimicrobial Agents:
  • Topical (Impetigo): Mupirocin or retapamulin twice daily for 5 days.
  • Oral (Ecthyma or Impetigo): 7-day regimen with S. aureus coverage.
    • MSSA suspected: Dicloxacillin or cephalexin.
    • MRSA suspected/confirmed: Doxycycline, clindamycin, or sulfamethoxazole-trimethoprim (SMX-TMP).
  • Poststreptococcal glomerulonephritis outbreaks: Systemic antimicrobials to eliminate nephritogenic S. pyogenes strains.

II. Purulent Skin and Soft Tissue Infections (SSTIs)

1. Evaluation and Diagnosis

• Gram stain and culture: Recommended for pus from carbuncles and abscesses but not mandatory in typical cases. Not recommended for inflamed epidermoid cysts.

2. Treatment Algorithm (Figure 1)

• Incision and Drainage: Primary treatment for inflamed epidermoid cysts, carbuncles, abscesses, and large furuncles (mild cases).
• Antibiotics as Adjunct to Incision and Drainage:
  • Consider antibiotics if: Systemic Inflammatory Response Syndrome (SIRS) is present (temperature >38°C, heart rate >90 bpm, respiratory rate >24 breaths/min, WBC count >12,000/µL).
  • MRSA coverage: Recommended for carbuncles or abscesses with:
    • Failed initial antibiotic treatment.
    • Markedly impaired host defenses.
    • SIRS and hypotension (severe cases).

Figure 1: Algorithm for management of patients with purulent skin and soft tissue infections.

III. Recurrent Skin Abscesses

1. Evaluation and Diagnosis

• Local Cause Investigation: Rule out pilonidal cyst, hidradenitis suppurativa, or foreign material at recurrent sites.
• Culture: Drain and culture recurrent abscesses early in infection.

2. Treatment

• Antibiotic Therapy: 5- to 10-day course based on culture results.
• Decolonization Regimen (for recurrent S. aureus infection):
  • Intranasal mupirocin twice daily for 5 days.
  • Daily chlorhexidine washes.
  • Daily decontamination of personal items (towels, sheets, clothes).
• Neutrophil Disorder Evaluation: Consider in adult patients with early childhood onset of recurrent abscesses.

IV. Erysipelas and Cellulitis

1. Evaluation and Diagnosis

• Routine Cultures: Blood or cutaneous aspirates/biopsies/swabs are not routinely recommended.
• Selective Cultures:
  • Blood cultures: Recommended.
  • Cutaneous aspirates/biopsies/swabs: Consider in malignancy on chemotherapy, neutropenia, severe cell-mediated immunodeficiency, immersion injuries, and animal bites.

2. Treatment Algorithm (Figure 1)

• Antimicrobial Therapy:
  • Mild Cellulitis (no systemic signs): Antibiotic active against streptococci.
  • Moderate Cellulitis (systemic signs): Systemic antibiotics, consider MSSA coverage.
  • Severe Cellulitis (penetrating trauma, MRSA risk factors, SIRS): Vancomycin or MRSA/streptococci effective agent.
  • Severely Compromised Patients: Broad-spectrum antimicrobial coverage may be considered. Vancomycin plus piperacillin-tazobactam or imipenem/meropenem for severe infections.
• Duration: 5 days, extend if no improvement.
• Adjunctive Measures:
  • Elevation of affected area.
  • Treat predisposing factors (edema, cutaneous disorders).
  • Interdigital toe space examination and treatment in lower-extremity cellulitis.
• Outpatient vs. Inpatient Therapy:
  • Outpatient: No SIRS, altered mental status, hemodynamic instability (mild cases).
  • Inpatient: Deeper/necrotizing infection concern, poor therapy adherence, immunocompromised, outpatient failure (moderate/severe cases).

V. Anti-inflammatory Agents for Cellulitis

1. Recommendation

• Systemic Corticosteroids: Consider in nondiabetic adult cellulitis patients (e.g., prednisone 40 mg daily for 7 days).

VI. Recurrent Cellulitis Management

1. Evaluation and Management

• Predisposing Condition Management: Identify and treat edema, obesity, eczema, venous insufficiency, toe web abnormalities.
• Prophylactic Antibiotics (for ≥3-4 episodes/year):
  • Oral penicillin or erythromycin twice daily for 4–52 weeks.
  • Intramuscular benzathine penicillin every 2–4 weeks.
  • Continue prophylaxis as long as predisposing factors persist.

VII. Surgical Site Infections (SSIs)

1. Treatment Algorithm (Figure 2)

• Incision and Drainage & Suture Removal: Essential for SSIs.
• Systemic Antimicrobial Therapy:
  • Not routine: Unless significant systemic response (erythema/induration >5cm, temperature >38.5°C, heart rate >110 bpm, WBC >12,000/µL).
  • Indicated: SSIs post-clean operations (trunk, head/neck, extremities) with systemic signs.
• Antibiotic Selection:
  • MSSA coverage: First-generation cephalosporin or antistaphylococcal penicillin.
  • MRSA risk factors: Vancomycin, linezolid, daptomycin, telavancin, or ceftaroline.
  • Axilla, GI tract, perineum, female genital tract operations: Agents against gram-negative bacteria and anaerobes (cephalosporin/fluoroquinolone + metronidazole).

Figure 2: Algorithm for management of surgical site infections.

VIII. Necrotizing Fasciitis

1. Evaluation and Treatment

• Urgent Surgical Consultation: For aggressive infections, systemic toxicity, necrotizing fasciitis or gas gangrene suspicion.
• Broad-Spectrum Empiric Antibiotics:
  • Vancomycin or linezolid PLUS piperacillin-tazobactam or carbapenem.
  • OR Vancomycin or linezolid PLUS ceftriaxone and metronidazole.
• Specific Therapy (documented group A streptococcal necrotizing fasciitis): Penicillin plus clindamycin.

IX. Pyomyositis

1. Diagnosis

• MRI: Recommended imaging modality. CT scan and ultrasound are also useful.
• Culture: Blood and abscess material cultures.

2. Treatment

• Empirical Therapy: Vancomycin initially. Add gram-negative bacilli agent for immunocompromised or post-trauma patients.
• MSSA-Specific Therapy: Cefazolin or antistaphylococcal penicillin.
• Drainage: Early drainage of purulent material.
• Repeat Imaging: For persistent bacteremia to find undrained foci.
• Duration: 2-3 weeks. IV antibiotics initially, oral switch when clinically improved.

X. Clostridial Gas Gangrene and Myonecrosis

1. Evaluation and Treatment

• Urgent Surgical Exploration and Debridement: Essential for suspected gas gangrene.
• Empiric Antibiotics (no definitive diagnosis): Vancomycin plus piperacillin/tazobactam, ampicillin/sulbactam, or carbapenem.
• Specific Therapy (clostridial myonecrosis): Penicillin and clindamycin.
• Hyperbaric Oxygen (HBO) Therapy: Not recommended due to lack of proven benefit and potential delay of surgical treatment.

XI. Animal and Human Bite Wounds Prevention

1. Preemptive Antimicrobial Therapy (Dog or Cat Bites – 3-5 days) Recommended for:

• Immunocompromised patients.
• Asplenic patients.
• Advanced liver disease patients.
• Preexisting/resultant edema in affected area.
• Moderate to severe injuries (especially hand/face).
• Injuries penetrating periosteum or joint capsule.
• Rabies Prophylaxis: Consider postexposure prophylaxis; consult local health officials.

XII. Infected Animal Bite Wound Treatment

1. Antimicrobial Therapy

• Agents active against aerobic and anaerobic bacteria (e.g., amoxicillin-clavulanate).

XIII. Tetanus Toxoid for Animal Bites

1. Administration

• Administer to patients without toxoid vaccination within 10 years. Tdap preferred over Td if not previously given.

XIV. Primary Wound Closure for Animal Bites

1. Recommendation

• Not generally recommended, except for facial wounds (copious irrigation, cautious debridement, preemptive antibiotics). Other wounds may be approximated cautiously.

XV. Cutaneous Anthrax Treatment

1. Naturally Acquired

• Oral penicillin V 500mg qid for 7–10 days.

2. Bioterrorism Cases (presumed aerosol exposure)

• Ciprofloxacin 500mg po bid or levofloxacin 500mg IV/po every 24 hours × 60 days.

XVI. Bacillary Angiomatosis and Cat Scratch Disease

1. Cat Scratch Disease Treatment

• Azithromycin:

  • 45 kg: 500 mg day 1, then 250 mg for 4 days.

  • <45 kg: 10 mg/kg day 1, then 5 mg/kg for 4 days.

2. Bacillary Angiomatosis Treatment

• Erythromycin 500 mg qid or doxycycline 100 mg bid for 2 weeks to 2 months.

XVII. Erysipeloid Treatment

1. Antimicrobial Therapy

• Penicillin (500 mg qid) or amoxicillin (500 mg tid) for 7–10 days.

XVIII. Glanders Treatment

1. Antimicrobial Therapy

• Ceftazidime, gentamicin, imipenem, doxycycline, or ciprofloxacin (based on in vitro susceptibility).

XIX. Bubonic Plague Diagnosis and Treatment

1. Diagnosis

• Gram stain and culture of aspirated material from suppurative lymph node.

2. Treatment

• Streptomycin (15 mg/kg IM every 12 hours) or doxycycline (100 mg bid po). Gentamicin is an alternative to streptomycin.

XX. Tularemia Diagnosis and Treatment

1. Diagnosis

• Serologic tests are preferred.

2. Treatment

• Severe cases: Streptomycin (15 mg/kg IM every 12 hours) or gentamicin (1.5 mg/kg IV every 8 hours).
• Mild cases: Tetracycline (500 mg qid) or doxycycline (100 mg bid po).
• Laboratory Notification: Notify lab if tularemia suspected.

XXI. SSTIs in Immunocompromised Patients – Assessment

1. Differential Diagnosis

• Consider non-infectious causes: drug eruption, malignancy infiltration, chemotherapy/radiation reactions, Sweet syndrome, erythema multiforme, leukocytoclastic vasculitis, graft-vs-host disease.
• Consider infectious causes: bacterial, fungal, viral, parasitic agents.

2. Diagnostic Approach

• Biopsy or aspiration of lesion for histology and microbiology as early diagnostic step.

XXII. SSTIs in Cancer Patients with Fever and Neutropenia – Assessment

1. Evaluation

• Determine episode type: initial, persistent, or recurrent fever and neutropenia.
• Aggressive etiology determination: aspiration/biopsy of SSTIs for cytology/histology, microbial staining, cultures.
• Risk stratification: High-risk (prolonged/profound neutropenia) vs. low-risk.
• Extent of infection: Thorough physical exam, blood cultures, chest radiograph, CT as needed.

XXIII. SSTIs in Initial Fever and Neutropenia Episodes – Antibiotic Therapy

1. Empiric Therapy

• Hospitalization and empiric antibacterial therapy: Vancomycin plus antipseudomonal antibiotics (cefepime, carbapenem, or piperacillin-tazobactam).

2. Directed Therapy

• Documented SSTIs: Treat based on antimicrobial susceptibilities.

3. Duration

• 7–14 days for most bacterial SSTIs.

4. Surgical Intervention

• Drainage of soft tissue abscess after marrow recovery or for progressive necrotizing fasciitis/myonecrosis.

5. Adjunct Therapy

• Colony-stimulating factors or granulocyte transfusions: Not routinely recommended.
• Acyclovir: For suspected/confirmed cutaneous/disseminated varicella zoster virus (HSV/VZV) infection.

XXIV. SSTIs in Persistent/Recurrent Fever and Neutropenia – Antimicrobial Therapy

1. Empiric Therapy

• Add empiric antifungal therapy (Table 6).
  • Consider vancomycin or gram-positive agents (linezolid, daptomycin, ceftaroline) if not already used.
  • Candida SSTIs: Echinocandin (or lipid amphotericin B if C. parapsilosis, fluconazole alternative). Treat for 2 weeks post-clearance/resolution.
  • Aspergillus SSTIs: Voriconazole (or lipid amphotericin B, posaconazole, echinocandin). Treat for 6–12 weeks.
  • Mucor/Rhizopus infections: Lipid amphotericin B (or posaconazole, consider echinocandin adjunct).
  • Fusarium species infections: High-dose IV voriconazole or posaconazole.
  • Antibiotic-resistant bacteria: Treat accordingly (Table 7).
  • Acyclovir: For suspected/confirmed cutaneous/disseminated HSV/VZV infections.

2. Diagnostic Evaluation

• Blood cultures and aggressive evaluation of skin lesions (culture, aspiration, biopsy, excision) for resistant microbes, yeast, molds.

3. Fungal Antigen Tests

• Single-serum fungal antigen tests (1,3-β-D-glucan or galactomannan): Low sensitivity, especially on antifungals.

4. PCR for HSV/VZV

• Peripheral blood PCR: Helpful for disseminated infection diagnosis in unexplained skin lesions.

XXV. SSTIs in Cellular Immunodeficiency – Assessment

1. Consultation

• Dermatologist consultation (familiar with cutaneous manifestations in cellular immunodeficiency).

2. Early Intervention

• Early biopsy and surgical debridement.

3. Empiric Therapy (Life-Threatening Situations)

• Consider empiric antibiotics, antifungals, and/or antivirals. Agent selection with primary team, dermatology, infectious disease, and other consultants.

This guideline provides a detailed algorithm for the diagnosis and treatment of various skin and soft tissue infections, emphasizing prompt diagnosis, appropriate antimicrobial selection, and surgical intervention when necessary, especially in immunocompromised individuals. The recommendations are based on expert consensus and evidence-based medicine, aiming to optimize patient outcomes and reduce complications from SSTIs.