What is the best treatment approach for a patient presenting with multiple cysts or abscesses on the head, considering potential underlying conditions and possible Methicillin-resistant Staphylococcus aureus (MRSA) infection?

Management of Multiple Cysts or Abscesses on the Head

For multiple cysts or abscesses on the scalp, incision and drainage is the primary treatment, with adjunctive antibiotics recommended when systemic signs are present, the patient is immunocompromised, or significant surrounding cellulitis exists. 1

Initial Assessment and Diagnosis

When evaluating multiple head lesions, distinguish between true abscesses (purulent collections requiring drainage) versus cellulitis (diffuse inflammation requiring antibiotics as primary therapy). 1 Key clinical features to assess include:

• Presence of fluctuance indicating drainable pus collection 1
• Systemic signs: fever, tachycardia, hypotension, altered mental status 1
• Extent of surrounding cellulitis beyond the abscess borders 1
• Patient risk factors: immunosuppression, diabetes, injection drug use, known MRSA colonization 1
• Size and number of lesions to guide drainage approach 2

Primary Treatment: Incision and Drainage

Incision and drainage alone achieves 85-90% cure rates for simple abscesses, regardless of antibiotic use. 1 For scalp abscesses:

• Perform drainage on all accessible lesions as the cornerstone of therapy 1
• Simple abscesses with limited surrounding erythema confined to the abscess borders may not require antibiotics 1
• Multiple aspirations may be needed for larger volume abscesses (>10 cc) 3

Antibiotic Therapy Indications

Add antibiotics when any of the following conditions are present: 1

• Systemic signs of infection (fever, SIRS criteria) 1
• Significant cellulitis extending beyond abscess borders 1
• Multiple abscesses or extensive disease involving multiple sites 1
• Immunocompromised state (diabetes, HIV, neutropenia, immunosuppressive therapy) 1
• Abscess >5 cm diameter 2
• Failed response to drainage alone 1
• Extremes of age (very young or elderly) 1
• Areas difficult to drain completely (near critical structures) 1

Empirical Antibiotic Selection

For Outpatient Management (Mild Cases)

First-line oral options for CA-MRSA coverage: 1

• Trimethoprim-sulfamethoxazole (TMP-SMX): preferred first-line agent 1
• Doxycycline or minocycline: effective alternatives 1
• Clindamycin: provides both MRSA and streptococcal coverage, but check local resistance rates (use only if <10% inducible resistance) 1
• Linezolid: effective but expensive, reserve for resistant cases 1

Important caveat: TMP-SMX and doxycycline have excellent CA-MRSA activity but uncertain activity against β-hemolytic streptococci. 1 Consider adding or switching to clindamycin if streptococcal infection is suspected based on clinical presentation (rapidly spreading erythema, well-demarcated borders suggesting erysipelas). 1

For Hospitalized Patients (Severe Cases)

For severe infections with systemic toxicity or rapid progression: 1

• Vancomycin: 15-20 mg/kg IV every 8-12 hours for MRSA and streptococcal coverage 1
• Alternative: Linezolid 600 mg IV/PO twice daily 1
• Duration: minimum 5 days, extend if not improved 1

For severely compromised patients with concern for polymicrobial infection: 1

• Vancomycin PLUS piperacillin-tazobactam or imipenem-meropenem for broad-spectrum coverage 1

Evaluation for Underlying Conditions

Recurrent abscesses at the same site warrant investigation for: 1

• Hidradenitis suppurativa: chronic inflammatory condition of apocrine glands 1
• Pilonidal cysts: particularly in occipital scalp region 1
• Foreign material: retained hair or debris 1
• Neutrophil dysfunction: if recurrent since early childhood 1

Decolonization for Recurrent Infections

For patients with recurrent MRSA skin infections, consider decolonization: 1

• Intranasal mupirocin 2% twice daily for 5 days 1
• PLUS daily bathing with chlorhexidine or dilute bleach (1/4-1/2 cup per full bath) for 5 days 1
• Extend measures to household contacts for better efficacy 1
• Evidence for effectiveness in the CA-MRSA era is limited, but may be attempted 1

Critical Pitfalls to Avoid

• Do not use "cellulitis" terminology for infections with purulent collections—this leads to antibiotic-only treatment when drainage is required 1
• Do not use rifampin as monotherapy—resistance develops rapidly 1
• Avoid clindamycin for serious infections if inducible resistance is present 1
• Do not assume antibiotics alone will cure abscesses—inadequate drainage is the primary cause of treatment failure, not antibiotic choice 4, 2
• For abscesses <5 cm in immunocompetent patients, drainage alone is usually sufficient; antibiotics may not provide additional benefit 2

Follow-up and Monitoring

• Reassess within 48-72 hours to ensure clinical improvement 1
• Hospitalize if: SIRS criteria present, hemodynamic instability, altered mental status, concern for deeper/necrotizing infection, or poor adherence anticipated 1
• Culture all drained material to guide targeted therapy and track local resistance patterns 1