What are the treatment options for molluscum contagiosum?

Treatment Options for Molluscum Contagiosum

Molluscum contagiosum typically resolves spontaneously within 6-12 months without treatment, but several treatment options are available for cases that are cosmetically bothersome, symptomatic, or to reduce transmission risk.

Natural Course and When to Treat

• Molluscum contagiosum is a common, benign viral skin infection presenting as skin-colored papules with central umbilication 1
• Affects 5-11% of children aged 0-16 years, most commonly on the trunk, face, and extremities 1
• Spontaneous resolution typically occurs within 6-12 months, though complete resolution can take up to 4 years 1
• Treatment is indicated primarily for:
  • Cosmetically bothersome lesions
  • Patients with underlying skin conditions like eczema
  • Symptomatic cases (pain, itching, redness)
  • Reducing risk of transmission
  • Athletes participating in contact sports

First-Line Treatment Options

Physical Removal Methods

1. Incision and Curettage:

   • Involves aggressive curettage to cause bleeding 1
   • Effective for immediate removal of visible lesions
   • May be painful and potentially frightening for young children

2. Cryotherapy with Liquid Nitrogen:

   • Similar efficacy to other treatments in children 1
   • Caution: May cause postinflammatory hyperpigmentation or scarring 1
   • High-quality evidence from a randomized controlled trial showed cantharidin was more effective than placebo (36.2% vs 10.6% clearance rate) 2

3. Simple Excision:

   • Direct removal of lesions 1
   • Best for isolated, larger lesions

4. Excision and Cautery:

   • Combines removal with heat treatment 1
   • More definitive but potentially more painful

Topical Treatments

1. 10% Potassium Hydroxide (KOH):

   • Effective treatment option 1
   • Comparative studies show it may be more effective than 5% imiquimod (faster onset of action) 3
   • Higher incidence of side effects than imiquimod 3

2. Cantharidin:

   • Open-label and observational studies indicate effectiveness 1
   • Recent high-quality evidence from a randomized controlled trial showed 36.2% clearance rate compared to 10.6% with placebo 2
   • Well-tolerated with minimal side effects 2

Second-Line and Less Effective Options

1. Imiquimod 5% cream:

   • Multiple high-quality studies show lack of effectiveness compared to vehicle/placebo 4
   • Moderate-quality evidence shows no difference in clinical cure rates at 12,18, or 28 weeks 4
   • May cause application site reactions (erythema, itching, burning) 5, 4
   • FDA labeling indicates it was not effective in pediatric trials 5

2. Other Topical Agents:

   • 10% Australian lemon myrtle oil (limited evidence) 4
   • 10% benzoyl peroxide cream 4
   • 5% sodium nitrite with 5% salicylic acid 4
   • Iodine plus tea tree oil 4

Treatment Algorithm

1. For asymptomatic, limited lesions in immunocompetent patients:

   • Consider observation for spontaneous resolution
   • Monitor for 3-6 months

2. For bothersome, extensive, or symptomatic lesions:

   • First choice: Cantharidin application or 10% potassium hydroxide
   • Alternative: Cryotherapy with liquid nitrogen (caution regarding pigmentation changes)

3. For lesions in sensitive areas or in young/anxious children:

   • 10% potassium hydroxide solution applied 3 times weekly
   • Consider cantharidin for its well-tolerated profile

4. For athletes participating in contact sports:

   • More aggressive treatment approach to prevent transmission
   • Cover lesions during competition until fully resolved
   • Follow specific return-to-play guidelines from athletic organizations 1

Special Considerations

• Immunocompromised patients: May require more aggressive treatment and monitoring
• Ocular involvement: Lesions on eyelids require prompt treatment to prevent conjunctivitis 1
• Children: Consider less painful options; avoid imiquimod as studies show lack of efficacy 5, 4
• Multiple lesions: Identify and treat nascent lesions to reduce recurrence risk 1

Common Pitfalls and Caveats

1. Overtreatment: Remember that spontaneous resolution is common; aggressive treatment may not be necessary for all cases
2. Imiquimod use: Despite widespread use, high-quality evidence shows it's no more effective than placebo 4
3. Pain management: Physical removal methods can be painful; consider topical anesthetics for children
4. Secondary infection: Monitor for signs of bacterial superinfection
5. Recurrence: New lesions may appear during treatment course; patient education is important

In adults with large and multiple molluscum lesions with minimal inflammation, consider evaluation for immunocompromised state 1.