How to manage a patient with molluscum contagiosum, considering treatment options and potential complications?

Management of Molluscum Contagiosum

For symptomatic, multiple, or periocular lesions, physical removal methods (cryotherapy, curettage, or excision) are first-line therapy, while asymptomatic limited disease can be managed with watchful waiting as spontaneous resolution typically occurs within 6-12 months. 1

Initial Assessment

Confirm diagnosis by identifying characteristic skin-colored, whitish, or pink papules with shiny surface and central umbilication, typically on trunk, face, and extremities 1. Early lesions may appear as simple dome-shaped papules without visible umbilication 1.

Key clinical features to assess:

• Number and distribution of lesions 1
• Presence of associated conjunctivitis if lesions are on or near eyelids 1
• Signs of immunocompromise: multiple large lesions with minimal inflammation should prompt HIV/immunodeficiency screening 1, 2
• Presence of perilesional eczema or inflammatory reactions 1

Treatment Algorithm

For Immunocompetent Patients

Physical removal methods (first-line for active treatment):

• Cryotherapy with liquid nitrogen: Achieves 93% complete response rate 1. Apply until visible freezing extends slightly beyond lesion margin into normal skin 1. Avoid sensitive areas (eyelids, lips, nose, ears) due to higher complication risk 1. Most common adverse effect is postinflammatory hyperpigmentation lasting 6-12 months, particularly in darker skin tones 1.

• Curettage/excision: Equally effective as cryotherapy 1, 2. Recommended for limited number of lesions where immediate removal is desired 2.

Topical chemical treatments:

• 10% potassium hydroxide solution: Similar efficacy to cryotherapy (86.6% complete response) with better cosmetic outcomes due to lower hyperpigmentation risk 1. Preferred for facial lesions or darker skin 1.

• Cantharidin: Effective in observational studies though randomized trial evidence is limited 1, 3. Useful alternative when other methods are not tolerated 3.

Critical treatment principle: Identify and treat ALL lesions including nascent ones during initial treatment, as missing early lesions is the most common cause of recurrence 1. Reducing viral load allows host immune response to eliminate residual virus 1, 2.

For Pediatric Patients (Ages 2-12)

Same treatment options as adults apply 1, 4. Avoid salicylic acid in children under 2 years due to systemic toxicity risk 4.

Watchful waiting is reasonable for asymptomatic, limited disease as spontaneous resolution occurs in 6-12 months (though can persist up to 4-5 years) 1, 4.

Special Circumstances

Periocular lesions with conjunctivitis:

• Physical removal is mandatory to resolve conjunctivitis 1, 2
• Conjunctivitis may require several weeks to resolve after lesion elimination 1, 2
• Monitor for persistent conjunctivitis requiring follow-up 1

Extensive or recalcitrant disease:

• Screen for immunocompromised state 1, 4
• Consider dermatology referral 1, 2

Immunocompromised patients:

• May present with atypical manifestations: giant (>5mm), disseminated, necrotic, or nodular forms without classic umbilication 1, 5
• Antiretroviral therapy (if HIV-positive) may lead to spontaneous resolution 5
• Topical imiquimod can be considered as adjunct, though evidence is limited 5

Treatments NOT Recommended

Imiquimod: Failed to show benefit compared to placebo in randomized controlled trials in both adults and children with molluscum contagiosum 1, 6. Two pediatric studies (n=702) showed no difference in clearance rates between imiquimod (24%) and vehicle (26-28%) 6. Do not use imiquimod for molluscum contagiosum 1, 4.

Ranitidine or H2 blockers: No evidence supporting efficacy for molluscum contagiosum 4. Guidelines do not include these among recommended treatments 4.

Prevention Counseling

• Avoid direct skin-to-skin contact with infected individuals 1
• Do not share towels, clothing, or personal items 1
• Cover all lesions with waterproof bandages if water exposure unavoidable 1
• Limit exposure to swimming pools/hot tubs associated with outbreaks 1
• Avoid scratching to prevent autoinoculation 1
• Hand hygiene with alcohol-based disinfectant or soap and water 1

Follow-Up

Follow-up is not usually necessary unless conjunctivitis persists or new lesions develop 1, 2. Return to communal water activities appropriate when all lesions completely resolved and no new lesions for several weeks 1.

Critical Pitfalls to Avoid

• Missing nascent lesions during initial treatment leads to recurrence 1
• Failing to recognize immunocompromise when multiple large lesions present with minimal inflammation 1, 2
• Using imiquimod despite lack of efficacy evidence 1, 6
• Undertreating periocular lesions with associated conjunctivitis 1, 2
• Applying cryotherapy to sensitive areas (eyelids, lips, nose, ears) 1