What is the recommended management for a superficial skin infection presenting as an infected bump after shaving and laser hair removal in a healthy adult without penicillin allergy?

Treatment of Infected Bump After Shaving and Laser Hair Removal

For a simple infected bump (furuncle/boil) after shaving or laser hair removal, incision and drainage is the primary treatment, and antibiotics are NOT needed unless there is extensive surrounding cellulitis (>5 cm), systemic signs of infection, or immunocompromise. 1, 2

Initial Assessment and Classification

Determine whether you're dealing with:

• Simple abscess/furuncle: A localized, fluctuant collection with minimal surrounding erythema (<5 cm) and no systemic symptoms 1, 2
• Folliculitis with cellulitis: Spreading erythema, warmth, and tenderness extending beyond the initial bump 1
• Multiple lesions or carbuncle: Coalescent inflammatory mass involving multiple follicles 1

The most common pathogen is Staphylococcus aureus from the patient's skin flora, with increasing prevalence of community-acquired MRSA (CA-MRSA) 1

Primary Treatment Approach

For Simple Abscess/Furuncle (Most Common Scenario)

• Incision and drainage (I&D) is the definitive treatment - open the abscess, evacuate all pus, probe to break up loculations, and apply a dry dressing 1, 3
• Do NOT prescribe antibiotics for simple abscesses with minimal surrounding erythema - they provide no clinical benefit and contribute to resistance 1, 2
• Moist heat application may promote drainage for very small furuncles 1

For Small Superficial Folliculitis Without Abscess Formation

• Topical mupirocin ointment applied three times daily for 8-12 days is highly effective, with 71-93% clinical efficacy rates 4, 5
• This is appropriate when there is superficial infection without a drainable collection 4, 5

When to Add Antibiotics

Add systemic antibiotics ONLY if any of these criteria are present: 1, 2

• Surrounding erythema extending >5 cm beyond the lesion
• Systemic inflammatory response (fever >38.5°C, pulse >100 bpm, hypotension, oliguria, altered mental status)
• Immunocompromised patient
• Incomplete drainage or inability to achieve adequate source control
• Multiple lesions or carbuncle formation 1

Antibiotic Selection When Indicated

First-line oral options targeting Gram-positive bacteria: 1

• Cephalexin or dicloxacillin for typical community-acquired infections
• Clindamycin or trimethoprim-sulfamethoxazole if CA-MRSA is suspected (prior MRSA infection, failed first-line therapy, high local prevalence) 1, 5
• Avoid penicillin alone - it is inadequate for S. aureus 5

Important caveat: Trimethoprim-sulfamethoxazole covers MRSA but is inadequate for streptococcal infections, so consider clindamycin if streptococcal infection is possible 5

Common Pitfalls to Avoid

• Do not prescribe antibiotics for simple abscesses - this is the most common error and contributes to antibiotic resistance without improving outcomes 1, 2
• Do not use topical disinfectants as primary treatment - they are inferior to appropriate antibiotics when antibiotics are indicated 5
• Do not culture routine simple abscesses - cultures are only needed if antibiotics become necessary or if there are recurrent infections 1, 2
• Do not simply aspirate - adequate I&D with probing to break loculations is essential for treatment success 1, 3

Special Considerations for Recurrent Infections

If the patient experiences repeated infections after shaving/laser hair removal: 1

• Check for nasal S. aureus colonization (20-40% of population are carriers)
• Consider nasal mupirocin application twice daily for 5-10 days to eradicate carriage
• Recommend bathing with chlorhexidine soap
• Ensure thorough laundering of towels and clothing
• Evaluate for underlying conditions like diabetes or immunosuppression

Follow-Up Expectations

• Simple abscesses typically resolve within 2-3 weeks without scarring after adequate drainage 5
• If no improvement within 48-72 hours after I&D, reassess for inadequate drainage, deeper infection, or need for antibiotics 1
• Wounds can be managed with simple dry dressings and heal by secondary intention 1, 2