Molluscum Contagiosum: Overview and Management
Molluscum contagiosum is a common, benign viral skin infection caused by a poxvirus that presents as skin-colored, dome-shaped papules with central umbilication, affecting 5-11% of children aged 0-16 years, and typically resolves spontaneously within 6-12 months but can persist up to 4 years. 1
Clinical Presentation
The infection manifests as:
- Characteristic lesions: Smooth-surfaced, pearly, firm papules (2-5 mm diameter) that are skin-colored, pink, yellow, or white with a distinctive central umbilication 2
- Distribution: Most commonly affects trunk, face, and extremities 1
- Symptoms: Usually asymptomatic, though may present with pain, itching, redness, or occasional bacterial superinfection 1
- Ocular involvement: When lesions occur on eyelids, viral shedding can cause conjunctivitis and keratitis, typically unilateral but can be bilateral with mild to severe follicular reaction 3, 4
Natural History and Prognosis
The infection is self-limited in immunocompetent individuals, with spontaneous resolution typically occurring in 6-12 months, though complete clearance can take up to 4 years. 1 This benign course must be weighed against the psychosocial burden, risk of transmission to others, and potential for spreading to additional body sites during the waiting period 5.
Treatment Approach
For Immunocompetent Patients
Despite the self-limiting nature, active treatment is recommended over "watchful waiting" to reduce transmission risk, shorten infection duration, and minimize psychosocial sequelae. 5
The most effective treatments based on guideline evidence include:
Physical removal methods (highest clearance rates):
- Curettage: 97.8% clearance rate with minimal local side effects 6
- 10% potassium hydroxide (KOH): 73.8% clearance rate, similar efficacy to cryotherapy in children 1, 6
- Cryotherapy with liquid nitrogen: Comparable efficacy to KOH but carries risk of postinflammatory hyperpigmentation or, uncommonly, scarring 1
Important caveat: When choosing between KOH and cryotherapy, select KOH for patients with darker skin tones to avoid hyperpigmentation risk from cryotherapy. 1
Topical chemical treatments:
- Podophyllotoxin: 75.0% clearance rate 6, 2
- Cantharidin: Shows effectiveness in open-label studies, though one small RCT (n=29) showed improvement over placebo that did not reach statistical significance 1
- Imiquimod: NOT recommended - shown to be no better than placebo in randomized controlled trials 1
For Ocular/Eyelid Lesions
Treatment to remove eyelid lesions is mandatory in symptomatic patients to eliminate viral shedding onto the ocular surface. 3, 4 Options include:
- Incision and curettage (aggressive enough to cause bleeding)
- Simple excision
- Excision with cautery
- Cryotherapy
Critical point: When treating multiple lesions, identify and treat nascent lesions to reduce recurrence risk. The conjunctivitis may require weeks to resolve after lesion elimination. 3
For Immunocompromised Patients
In adults with large and multiple molluscum lesions accompanied by relatively little conjunctival inflammation, suspect immunocompromised state (e.g., HIV). 3, 4 These patients develop severe and recalcitrant lesions requiring more aggressive treatment:
- Cidofovir
- Imiquimod (may be effective in this population despite failure in immunocompetent patients)
- Interferon
- Consider dermatology referral for examination of other suspicious lesions 2
Emerging Therapies
Berdazimer gel demonstrates favorable safety profiles, particularly for pediatric patients 6. Intralesional immunotherapies (Candida antigen, MMR vaccine) show encouraging results for persistent or recurring lesions 6.
Special Populations
Pregnancy: Physical procedures such as cryotherapy are safe 2
Athletes: Specific return-to-competition guidelines exist from NCAA, NFHS, and NATA (see Table 3 in source guidelines) 1
Patients with eczema: Treatment is indicated for lesions in cosmetically bothersome locations or when underlying skin conditions like eczema are present 1
Screening Recommendation
Patients with genital molluscum contagiosum should be screened for other sexually transmitted infections, as genital MC is well-recognized as a sexually transmitted disease in adults 2, 7.
Common Pitfalls to Avoid
- Do not use imiquimod - it has failed to show benefit in RCTs despite theoretical rationale 1
- Avoid cryotherapy in darker skin - select KOH instead to prevent hyperpigmentation 1
- Do not overlook nascent lesions during treatment - incomplete treatment leads to recurrence 3
- Do not dismiss large/multiple lesions in adults - evaluate for immunocompromised state 3, 4
- Do not adopt "watchful waiting" as default - active treatment reduces transmission, shortens duration, and prevents psychosocial burden 5