What are the treatment options for a patient with molluscum contagiosum, considering factors such as age, immune status, and overall health?

Treatment of Molluscum Contagiosum

Primary Treatment Recommendation

Physical removal methods—including curettage, simple excision, excision with cautery, or cryotherapy with liquid nitrogen—are the first-line treatments for molluscum contagiosum, particularly for symptomatic lesions, multiple lesions, or those near the eyes causing conjunctivitis. 1, 2, 3

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Treatment Algorithm by Clinical Scenario

For Immunocompetent Children and Adults

Active treatment is indicated for:

• Symptomatic lesions (painful, itchy, or inflamed) 1, 3
• Multiple lesions (to prevent autoinoculation and transmission) 1, 3
• Periocular lesions with associated conjunctivitis 1, 2, 3
• Patient/parent preference to avoid prolonged infectivity 1

Watchful waiting is reasonable for:

• Asymptomatic lesions 3
• Limited number of lesions 3
• No periocular involvement 3
• Lesions typically resolve spontaneously in 6-12 months, though can persist up to 4-5 years 1, 3

First-Line Physical Treatment Options

Cryotherapy with liquid nitrogen:

• Achieves complete response in approximately 93% of cases 1, 3
• Apply until visible freezing extends slightly beyond lesion margin into normal skin 1
• Major caveat: Risk of postinflammatory hyperpigmentation (most common adverse effect, may persist 6-12 months) or scarring, particularly concerning for facial lesions or darker skin tones 1, 3
• Avoid treating sensitive areas (eyelids, lips, nose, ears) due to higher complication risk 1

Curettage, excision, or excision with cautery:

• Equally effective first-line options 1, 2
• Better cosmetic outcomes than cryotherapy in many cases 1

First-Line Chemical Treatment Options

10% potassium hydroxide solution:

• The American Academy of Pediatrics recommends this as first-line chemical treatment 1, 3
• Similar efficacy to cryotherapy (86.6% complete response vs 93.3% for cryotherapy) 1
• Better cosmetic results with lower risk of hyperpigmentation compared to cryotherapy 1, 3

Cantharidin:

• Shows effectiveness in observational studies, though randomized controlled trial evidence is limited 1
• Practical option when available 4

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Critical Treatment Principles

Identify and treat ALL lesions, including nascent ones:

• Failure to treat early/small lesions is a common cause of recurrence 1, 2
• Reducing viral load allows the host immune response to eliminate residual virus 1, 2
• Examine carefully for nascent lesions during initial treatment 1

For periocular lesions with conjunctivitis:

• Physical removal is imperative to resolve conjunctivitis 1, 2
• Conjunctivitis may require several weeks to resolve after lesion elimination 1, 2
• Monitor for resolution at follow-up 1, 2

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Special Populations

Immunocompromised Patients

Multiple large lesions with minimal inflammation should prompt screening for immunocompromised state 1, 2

For extensive or recalcitrant disease:

• Consider referral to dermatology 1, 2
• May require alternative therapies (cidofovir, interferon) in severely immunosuppressed patients 5

Children Under 2 Years

Salicylic acid is contraindicated due to risk of systemic toxicity 3

Pregnant Patients

Physical procedures (cryotherapy, curettage) are safe to use 5

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Treatments to AVOID

Imiquimod:

• The FDA explicitly states that imiquimod cream failed to demonstrate efficacy in two randomized, vehicle-controlled trials in 702 pediatric subjects with molluscum contagiosum 6
• Complete clearance rates were 24% with imiquimod vs 26-28% with vehicle (no benefit) 6
• The American Academy of Pediatrics explicitly states imiquimod should not be used 1, 3, 6

H2 blockers (ranitidine, cimetidine):

• No evidence supporting efficacy 3
• Not included in current guidelines 3

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Follow-Up and Prevention

Follow-up is not usually necessary unless:

• Conjunctivitis persists after lesion removal 1, 2
• New lesions develop 2

Prevention measures:

• Hand hygiene with alcohol-based disinfectant or soap and water is the most important prevention method 1, 3
• Avoid sharing towels, clothing, and personal items 1, 3
• Cover all lesions with waterproof bandages if water exposure is unavoidable 1, 3
• Avoid skin contact with infected individuals 1

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Common Pitfalls

• Missing nascent lesions during initial treatment leads to recurrence 1
• Underestimating the need to treat periocular lesions, which require active treatment to prevent ocular complications 1
• Using imiquimod despite clear evidence of inefficacy 1, 3, 6
• Not considering immunocompromised state when seeing extensive disease with minimal inflammation 1, 2