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

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

Treatment Algorithm by Clinical Scenario

For Immunocompetent Children

• Watchful waiting is appropriate for asymptomatic lesions, limited disease, and no periocular involvement, as spontaneous resolution typically occurs in 6-12 months (though can persist up to 4-5 years) 1, 3
• Active treatment is indicated when lesions are symptomatic (painful, itchy), multiple, causing autoinoculation, or located near the eyes with associated conjunctivitis 1, 3

For Immunocompetent Adults

• Proceed directly with physical removal methods for limited disease 2
• Consider dermatology referral for extensive disease or if multiple large lesions with minimal inflammation are present (suggests possible immunocompromise) 2

For Immunocompromised Patients

• Screen for immunodeficiency if lesions are extensive, large, and have minimal inflammation 1, 2
• Refer to dermatology for management of extensive or recalcitrant disease 1

First-Line Treatment Options

Physical Removal Methods (Preferred)

• Cryotherapy with liquid nitrogen achieves complete response in approximately 93% of cases 1, 3
• Curettage, simple excision, or excision with cautery are equally effective alternatives recommended by the American Academy of Ophthalmology 1, 2, 3
• Treat ALL lesions, including nascent ones, during the initial treatment session to reduce recurrence risk, as reducing viral load allows the host immune response to eliminate residual virus 1, 2

Chemical Treatments (Alternative)

• 10% potassium hydroxide solution has similar efficacy to cryotherapy (86.6% vs 93.3% complete response) with better cosmetic results due to lower risk of postinflammatory hyperpigmentation 1, 3
• Cantharidin shows effectiveness in observational studies, though randomized controlled trial evidence is limited 1

Critical Treatment Considerations

Periocular Lesions

• Physical removal is mandatory for lesions on or near eyelids with associated conjunctivitis 1, 2, 3
• Conjunctivitis may require several weeks to resolve after lesion elimination 1, 2
• Monitor for resolution of conjunctivitis at follow-up 1, 3

Cosmetic and Safety Concerns

• Cryotherapy carries higher risk of postinflammatory hyperpigmentation or scarring, particularly concerning for facial lesions or darker skin tones 1, 3
• Avoid cryotherapy on sensitive areas including eyelids, lips, nose, and ears due to higher complication risk 1
• Potassium hydroxide provides better cosmetic outcomes compared to cryotherapy 1

Age-Specific Restrictions

• Salicylic acid is contraindicated in children under 2 years due to risk of systemic toxicity 3

Treatments to AVOID

Imiquimod (Critical)

• Do NOT use imiquimod for molluscum contagiosum—the American Academy of Pediatrics explicitly states it showed no benefit compared to placebo in randomized controlled trials 1, 3
• FDA label confirms failure to demonstrate efficacy: Two pediatric studies (702 subjects) showed complete clearance rates of 24% with imiquimod versus 26-28% with vehicle 4
• Imiquimod is NOT FDA-approved for molluscum contagiosum and should only be used for actinic keratosis, superficial basal cell carcinoma, or external genital warts 4

Other Ineffective Treatments

• Ranitidine or H2 blockers have no evidence supporting efficacy and are not included in current guidelines 3

Common Pitfalls and How to Avoid Them

Missing Nascent Lesions

• Examine carefully for early lesions during initial treatment, as their omission is a frequent cause of recurrence 1
• Early lesions may appear as simple dome-shaped papules without visible umbilication 1

Underestimating Immunocompromise

• Multiple large lesions with minimal inflammation should prompt immunodeficiency screening 1, 2
• Atypical presentations (giant, disseminated, necrotic forms) warrant dermatology referral 1

Inadequate Follow-Up

• Follow-up is generally not necessary unless conjunctivitis persists or new lesions develop 1, 2
• For periocular lesions with conjunctivitis, schedule follow-up to confirm resolution 1, 3

Prevention and Transmission Control

• 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
• Limit exposure to swimming pools and hot tubs associated with known outbreaks 1
• Lesions remain infectious throughout their course until complete resolution 1