What is the appropriate treatment for a molluscum contagiosum lesion that is secondarily infected with pus?

Treatment of Secondarily Infected Molluscum Contagiosum

For molluscum contagiosum lesions with purulent drainage indicating true bacterial superinfection, initiate appropriate antibiotic therapy based on culture results while simultaneously performing physical removal of the lesion (curettage, excision, or cryotherapy) to eliminate the viral reservoir. 1

Distinguishing True Bacterial Superinfection from Inflammatory Response

The critical first step is determining whether you're dealing with true bacterial superinfection versus normal inflammatory erythema:

• True bacterial superinfection presents with purulent drainage, marked surrounding cellulitis, or systemic signs like fever—these require culture confirmation before starting antibiotics 1
• Simple inflammatory erythema around molluscum lesions often represents a normal immune response as the body clears the virus and does not require antibiotics 1
• In immunocompromised patients with atypical presentations (large, necrotic, or minimally inflamed lesions), consider cryptococcal infection in your differential and obtain fungal cultures 1

Treatment Algorithm for Infected Lesions

Step 1: Culture and Antibiotic Selection

• Obtain bacterial culture from purulent drainage before initiating antibiotics 1
• Start empiric antibiotics covering common skin pathogens (typically Staphylococcus aureus and Streptococcus species) if cellulitis or systemic signs are present
• Adjust antibiotic therapy based on culture results and clinical response

Step 2: Definitive Lesion Removal

Once infection is controlled or concurrently with antibiotic therapy, perform physical removal:

• Incision and curettage is the recommended first-line physical removal method 1, 2
• Simple excision or excision with cautery are equally effective alternatives 1, 2
• Cryotherapy with liquid nitrogen achieves approximately 93% complete response and is another first-line option 1, 2

Step 3: Comprehensive Lesion Treatment

• Identify and treat ALL lesions, including nascent ones that may not yet be visible, to reduce recurrence risk 1, 2
• Reducing viral load through complete treatment allows the host immune response to eliminate residual virus 1, 2

Special Considerations for Immunocompromised Patients

• Immunosuppressed individuals may develop chronic ulcerated molluscum lesions with ongoing viral replication that become complicated by secondary bacterial AND fungal superinfections 1
• Multiple large lesions with minimal inflammation should prompt screening for immunocompromised state 1, 2
• These patients require more aggressive treatment as lesions persist for prolonged periods and spontaneous resolution is unlikely 1
• Consider dermatology referral for extensive or recalcitrant disease 1, 2

Critical Pitfalls to Avoid

• Do not delay physical removal while treating bacterial superinfection—the viral reservoir must be eliminated to prevent ongoing complications 1, 2
• Do not miss nascent lesions during initial treatment, as this is a common cause of recurrence 1
• Do not assume all purulent-appearing lesions are infected—many represent normal inflammatory responses that don't require antibiotics 1
• Do not use imiquimod as it has not shown benefit compared to placebo in randomized controlled trials 1

Follow-Up Monitoring

• Follow-up is generally not necessary unless conjunctivitis persists (if lesions were periocular) or new lesions develop 1, 2
• Monitor for resolution of cellulitis within 48-72 hours of appropriate antibiotic therapy
• If lesions recur, re-examine carefully for missed nascent lesions 1