How long is Molluscum contagiosum contagious?

Molluscum Contagiosum: Contagious Period and Management

Molluscum contagiosum remains contagious from the time lesions appear until they have completely resolved, which typically takes 6-12 months but can last up to 4 years in some cases. 1

Contagious Period and Transmission

• Molluscum contagiosum is a viral skin infection that spreads through:
  • Direct skin-to-skin contact
  • Contact with contaminated objects (fomites)
  • Autoinoculation (spreading to other parts of one's own body)
• The virus remains transmissible as long as visible lesions are present 2
• Complete resolution typically occurs within:
  • 6-12 months in most cases 1
  • Up to 4 years in some individuals 1
  • 6 months to 5 years according to some reports 2

Risk Factors for Prolonged Contagious Period

• Immunocompromised status (significantly longer duration) 2
• Multiple or extensive lesions
• Continued autoinoculation through scratching
• Delayed or no treatment intervention

Treatment Considerations to Reduce Contagious Period

The American Academy of Pediatrics recommends different approaches based on clinical presentation:

For Limited, Asymptomatic Lesions:

• Observation for spontaneous resolution with monitoring for 3-6 months is appropriate for uncomplicated cases 1

For Bothersome, Extensive, or Symptomatic Lesions:

1. First-line treatments:

   • Cantharidin application (well-tolerated and effective) 1, 3
   • 10% potassium hydroxide (comparable efficacy to cryotherapy with 86.6% complete response rate) 1

2. Alternative treatments:

   • Cryotherapy with liquid nitrogen (93.3% complete response rate) 1
   • Caution: May cause postinflammatory hyperpigmentation or scarring
   • May require weekly applications for up to 4 weeks

3. Not recommended:

   • Imiquimod (randomized controlled trials show it is not more effective than placebo) 1, 4

Special Populations Requiring More Aggressive Treatment:

• Athletes in contact sports (to prevent transmission) 1
• Immunocompromised patients (more extensive disease) 1
• Patients with ocular involvement (to prevent conjunctivitis) 1

Prevention of Transmission

While lesions are present:

• Avoid touching or scratching lesions
• Cover lesions when possible, especially during contact activities
• Avoid sharing personal items (towels, clothing, bathing equipment)
• Avoid swimming pools until lesions resolve
• For sexually transmitted cases, avoid intimate contact until complete resolution 1

Important Clinical Considerations

• Treatment does not immediately eliminate contagiousness - lesions remain contagious until they have completely resolved
• Multiple treatment sessions may be needed for complete clearance
• New lesions may continue to appear during treatment as previously inoculated virus emerges
• Patient education about preventing spread is essential during the entire contagious period
• For children or anxious patients, 10% KOH or cantharidin are preferred due to better tolerability 1

Remember that even with treatment, the virus remains contagious until all lesions have completely resolved, making prevention measures important throughout the entire course of the infection.