> Table of Contents > Molluscum Contagiosum
Molluscum Contagiosum
Erica F. Crannage, PharmD, BCPS, BCACP
Rupal Trivedi, MD
image BASICS
DESCRIPTION
Molluscum contagiosum is a common, benign, viral (poxvirus) skin infection, characterized by small (2 to 5 mm), waxy white or flesh-colored, domeshaped papules with central umbilication. When lesions are opened, a creamy, white-gray material can be expressed. Molluscum contagiosum is highly contagious and spreads by autoinoculation, skin-toskin contact, sexual contact, and shared clothing/towels. Molluscum contagiosum is a self-limited infection in immunocompetent patients but can be difficult to treat and disfiguring in immunocompromised patients.
EPIDEMIOLOGY
Prevalence
  • 1% in the United States, occurring mainly in children 2 to 15 years and sexually active young adults
  • 5-18% HIV population
ETIOLOGY AND PATHOPHYSIOLOGY
  • DNA virus; Poxviridae family
  • Four genetic virus types, clinically indistinguishable
  • Virions invade and replicate in cytoplasm of epithelial cells causing abnormal cell proliferation
  • Genome encodes proteins to evade host immune system.
  • Incubation period: 2 to 6 weeks
  • Time to resolution: 6 to 24 months
  • Not associated with malignancy
  • No cross-hybridization or reactivation by other poxviruses
RISK FACTORS
  • Skin-to-skin contact with infected person
  • Contact sports
  • Swimming
  • Eczema, atopic dermatitis
  • Sexual activity with infected partner
  • Immunocompromised: HIV, chemotherapy, corticosteroid therapy, transplant patients
GENERAL PREVENTION
  • Avoid skin-to-skin contact with host (e.g., contact sports, sexual activity).
  • Avoid sharing clothing and towels.
COMMONLY ASSOCIATED CONDITIONS
  • Atopic dermatitis
  • Immunosuppression medications: corticosteroids, chemotherapy
  • HIV/AIDS
image DIAGNOSIS
PHYSICAL EXAM
  • Perform thorough skin exam including conjunctiva and anogenital area
  • Discrete, firm papules with a central umbilication
  • Umbilication is not obvious in small children.
  • White curdlike core under umbilicated center
  • Lesions are flesh, pearl, or red in color.
  • May have surrounding erythema or dermatitis
  • Immunocompetent hosts: average of 11 to 20 lesions, 2 to 5 mm diameter (range: 1 to 10 mm)
  • Hosts with HIV/AIDS: hundreds of widespread lesions
  • Children: trunk, extremities, face, anogenital region
  • Sexually active: inner thighs, anogenital area
Pediatric Considerations
  • Infants <3 months, consider vertical transmission
  • Children: fever, >50 lesions, limited response to therapy, consider immunodeficiency
  • Children: anogenital lesions, consider autoinoculation/possible sexual abuse
DIFFERENTIAL DIAGNOSIS
  • AIDS patients: cryptococcus, penicilliosis, histoplasmosis, coccidioidomycosis
  • Basal cell carcinoma
  • Benign appendageal tumors: syringomas, hydrocystomas, ectopic sebaceous glands
  • Condyloma acuminatum
  • Dermatofibroma
  • Eyelid: abscess, chalazion, foreign-body granuloma
  • Folliculitis/furunculosis
  • Keratoacanthoma
  • Oral squamous cell carcinoma
  • Trichoepithelioma
  • Verruca vulgaris
  • Warty dyskeratoma
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
  • Virus cannot be cultured.
  • Culture lesion if concern is secondary infection
  • Sexual transmission: Test for other sexually transmitted infections, including HIV.
  • Microscopy: scrape lesion
    • Core material has characteristic Henderson-Paterson intracytoplasmic viral inclusion bodies.
    • Crush prep with 10% potassium hydroxide will show characteristic inclusion bodies as well.
    • Alternatively, hematoxylin-eosin-stained formalinfixed tissue shows same confirmatory features.
Diagnostic Procedures/Other
Clinical; using magnifying lens
Tests Interpretation
Molluscum cytoplasmic inclusion bodies within keratinocytes
image TREATMENT
GENERAL MEASURES
  • In healthy patients, molluscum contagiosum is generally self-limited and heals spontaneously.
  • No single intervention is shown to be convincingly more effective than any other in treating molluscum contagiosum (1)[B].
  • No treatment is FDA-approved for treatment of molluscum contagiosum.
  • Three categories of treatment: destructive, immuneenhancing, and antiviral
MEDICATION
First Line
  • Cantharidin 0.7-0.9% solution: In office application to lesions, cover with dressing; wash off in 2 to 6 hours or sooner if blistering. Repeat treatment every 2 to 4 weeks until lesions resolve (1)[B],(2,3)[C].
    • Not commercially available in the United States but may be obtained from Canada
    • Adverse effects: blistering, erythema, pain, pruritus
    • Precautions: Do not use on face or on genital mucosa.
Second Line
  • Benzoyl peroxide 10% cream: Apply to each lesion twice daily for 4 weeks (1)[B].
    • Inexpensive
    • Adverse effects: mild dermatitis
  • For immunocompromised patients with refractory lesions, consider
    • Starting or maximizing HAART therapy in patients with HIV/AIDS (4)[C]
    • P.683

    • Cidofovir
      • 3% cream applied to lesions once daily, 5 days/week for 8 weeks (4)[C]
      • 1% cream applied to lesions once daily, 5 days/week for 2 weeks, repeat in 1 month, if necessary (4)[C]
      • Adverse effects with topical use: erythema, pain, pruritus, erosions
      • 3 to 5 mg/kg IV weekly for 1 to 2 weeks, followed by IV infusions every other week, until clinical clearance or up to 9 infusions (5)[C]
      • Adverse effects with IV use: nephrotoxicity, neutropenia
      • Monitoring with IV use: renal function and complete blood counts prior to and 24 to 48 hours after infusions
      • Precaution: Must coadminister oral probenecid and provide IV hydration with each IV infusion; refer to cidofovir manufacturer's recommendations on dosing.
    • Ingenol mebutate 0.015% gel applied to lesions once daily for 3 days; may repeat once if needed (6)[C] very expensive
      • Adverse effects: erythema, irritation
SURGERY/OTHER PROCEDURES
Considered first line
  • Cryotherapy: 5 to 10 seconds with 1- to 2-mm margins; repeat every 3 to 4 weeks as needed until lesions disappear (7)[B].
    • Adverse effects: erythema, edema, pain, blistering
    • Contraindications: cryoglobulinemia, Raynaud disease
  • Curettage under local or topical anesthesia (1)[A],(8)[B]
    • Adverse effects: pain, scarring
COMPLEMENTARY & ALTERNATIVE MEDICINE
  • Australian lemon myrtle oil: Apply 10% solution once daily for 21 days (9)[B].
  • Potassium hydroxide 5-10% solution: Apply 1 to 2 times a day until the lesions disappeared completely (10)[B].
Pediatric Considerations
  • Surgical interventions: Second line in small children due to associated pain
  • Pain control: Pretreat with topical lidocaine or EMLA before surgical treatment.
  • Note: Adverse effect:
    • Lidocaine or EMLA over large body surface area: Methemoglobinemia and CNS toxicity. Refer to manufacturer's recommendations on dosing and use in children.
Pregnancy Considerations
Safe in pregnancy: curettage, cryotherapy, incision, and expression
image ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
Depends on type of treatment
PATIENT EDUCATION
  • Cover lesions to prevent spread.
  • Avoid scratching.
  • Avoid contact sports.
  • Avoid sharing towels and clothing.
  • Avoid sexual activity when lesions present.
PROGNOSIS
  • Immunocompetent: self-limited, resolves in 3 to 12 months (range: 2 months to 4 years)
  • Immunocompromised: lesions difficult to treat; may persist for years
REFERENCES
1. van der Wouden JC, Menke J, Gajadin S, et al. Interventions for cutaneous molluscum contagiosum. Cochrane Database Syst Rev. 2006;(2):CD004767.
2. Moye V, Cathcart S, Burkhart CN, et al. Beetle juice: a guide for the use of cantharidin in the treatment of molluscum contagiosum. Dermatol Ther. 2013;26(6):445-451.
3. Silverberg NB, Sidbury R, Mancini AJ. Childhood molluscum contagiosum: experience with cantharidin therapy in 300 patients. J Am Acad Dermatol. 2000;43(3):503-507.
4. Chen X, Anstey AV, Bugert JJ. Molluscum contagiosum virus infection. Lancet Infect Dis. 2013;13(10):877-888.
5. Erikson C, Driscoll M, Gaspari A. Efficacy of intravenous cidofovir in the treatment of giant molluscum contagiosum in a patient with human immunodeficiency virus. Arch Dermatol. 2011;147(6):652-654.
6. Javed S, Tyring SK. Treatment of molluscum contagiosum with ingenol mebutate. J Am Acad Dermatol. 2014;70(5):e105.
7. Al-Mutairi N, Al-Doukhi A, Al-Farag S, et al. Comparative study on the efficacy, safety, and acceptability of imiquimod 5% cream versus cryotherapy for molluscum contagiosum in children. Pediatr Dermatol. 2010;27(4):388-394.
8. Hanna D, Hatami A, Powell J, et al. A prospective randomized trial comparing the efficacy and adverse effects of four recognized treatments of molluscum contagiosum in children. Pediatr Dermatol. 2006;23(6):574-579.
9. Burke BE, Baillie JE, Olson RD. Essential oil of Australian lemon myrtle (Backhousia citriodora) in the treatment of molluscum contagiosum in children. Biomed Pharmacother. 2004;58(4):245-247.
10. Can B, Topaloglu F, Kavlale M, et al. Treatment of pediatric molluscum contagiosum with 10% potassium hydroxide solution. J Dermatolog Treat. 2014;25(3):246-248.
Additional Reading
&NA;
  • Brown J, Janniger CK, Schwartz RA, et al. Childhood molluscum contagiosum. Int J Dermatol. 2006;45(2):93-99.
  • Dohil MA, Lin P, Lee J, et al. The epidemiology of molluscum contagiosum in children. J Am Acad Dermatol. 2006;54(1):47-54.
  • Olsen JR, Gallacher J, Piguet V, et al. Epidemiology of molluscum contagiosum in children: a systematic review. Fam Pract. 2014;31(2):130-136.
  • Ting PT, Dytoc MT. Therapy of external anogenital warts and molluscum contagiosum: a literature review. Dermatol Ther. 2004;17(1):68-101.
Codes
&NA;
ICD10
B08.1 Molluscum contagiosum
Clinical Pearls
&NA;
  • Natural resolution is preferred treatment in healthy patients.
  • Reassure parents that lesions will heal naturally and generally resolve without scarring.
  • No specific treatment has been identified as superior to any other.
  • Consider topical corticosteroids for pruritus or associated dermatitis.