Are recurrent purulent infections or boils sufficient to presume Methicillin-resistant Staphylococcus aureus (MRSA) colonization and initiate treatment with chlorhexidine (CHG) wash without a positive MRSA culture?

Recurrent Purulent Infections and Presumptive MRSA Management

No, recurrent purulent infections or boils alone are not sufficient to presume MRSA colonization or initiate chlorhexidine decolonization without culture confirmation—you must first culture the infection, optimize hygiene measures, and only consider decolonization if infections recur despite these interventions. 1

Initial Management of Recurrent Abscesses

Step 1: Culture and Drain Early

• Recurrent abscesses should be drained and cultured early in the course of infection to identify the causative pathogen 1
• Incision and drainage is the primary treatment for simple abscesses or boils, and antibiotics are not routinely needed for simple abscesses 1
• Cultures are particularly important in recurrent cases to guide targeted antibiotic therapy rather than presumptive treatment 1

Step 2: Rule Out Local Anatomic Causes

• A recurrent abscess at the same site should prompt evaluation for pilonidal cyst, hidradenitis suppurativa, or foreign material—addressing these local factors can be curative 1, 2
• Adult patients with recurrent abscesses that began in early childhood should be evaluated for neutrophil disorders 1

Step 3: Consider Targeted Antibiotic Therapy

• After obtaining cultures, treat with a 5-10 day course of an antibiotic active against the isolated pathogen 1
• This is a weak recommendation with low-quality evidence, but it provides pathogen-directed therapy rather than empiric MRSA coverage 1

When to Consider Decolonization (Not Before)

Prerequisites Before Decolonization

Decolonization should only be considered after the following conditions are met:

1. The patient has documented MRSA infection (at least one prior culture-confirmed MRSA infection) 1, 3
2. Hygiene measures have been optimized and failed to prevent recurrence 1, 3
3. Either: The patient continues to develop recurrent SSTI despite wound care optimization, OR ongoing transmission is occurring among household members 1, 3

The Decolonization Regimen (If Indicated)

• Intranasal mupirocin 2% ointment twice daily for 5-10 days PLUS daily chlorhexidine gluconate body washes for 5-14 days (or dilute bleach baths: 1 teaspoon per gallon of water for 15 minutes twice weekly for 3 months) 1, 3
• Decolonization must be offered in conjunction with ongoing reinforcement of hygiene measures, not as a replacement 3

Hygiene Measures That Must Be Implemented First

Personal Hygiene Requirements

• Keep all draining wounds covered with clean, dry bandages 1, 3
• Maintain hand hygiene with soap and water or alcohol-based hand gel, particularly after touching infected skin 1, 3
• Avoid sharing personal items such as towels, sheets, razors, and clothing 1, 2
• Wash towels, sheets, and clothing in hot water daily during active infection 2

Environmental Cleaning

• Clean high-touch surfaces that contact bare skin daily with commercially available cleaners 1, 3
• Focus on surfaces like doorknobs, light switches, and bathroom fixtures 3

Critical Pitfalls to Avoid

The Evidence Is Weak for Community-Acquired MRSA

• Most studies showing benefit of decolonization were conducted in healthcare settings or with MSSA, not community-acquired MRSA 1, 3
• The pathogenesis of recurrent CA-MRSA infection is unclear and likely involves complex interplay between pathogen, host colonization, patient behavior, and environmental exposures 1
• Decolonization may only provide temporary clearance, with recolonization occurring after discontinuation 2

Don't Skip Cultures

• Screening cultures prior to decolonization are not routinely recommended if at least one prior infection was documented as MRSA 1, 3
• However, you cannot presume MRSA without ever having obtained a culture—at least one documented MRSA infection is needed before considering decolonization 1, 3
• Surveillance cultures following decolonization are not routinely recommended in the absence of active infection 1, 3

Chlorhexidine Alone Is Insufficient

• Whole-body washing with chlorhexidine can reduce skin colonization but appears insufficient for complete eradication without addressing other colonized sites (gastrointestinal tract, wounds) 4
• A randomized controlled trial found no significant difference in 30-day MRSA eradication between chlorhexidine body washing plus mupirocin versus placebo plus mupirocin (7% vs 11%, p=0.47) 4
• Chlorhexidine is most effective when combined with intranasal mupirocin as part of a comprehensive decolonization strategy 1, 3

Household Contact Management

When to Evaluate Contacts

• Symptomatic contacts should be evaluated and treated for possible MRSA infection 1
• Nasal and topical body decolonization of asymptomatic household contacts may be considered if ongoing transmission is occurring despite hygiene measures 1
• A pediatric study found that employing preventive measures for both the patient and household contacts resulted in significantly fewer recurrences than treating the patient alone 2