Molluscum Contagiosum

See Also

Pathophysiology

Not a wart virus (But often confused with these)
Caused by DNA containing Poxvirus
1. Poxviruses also include mpox and Smallpox
Transmission
1. Direct contact
2. Fomites (e.g. shared towels)
3. Autoinoculation (e.g. scratching)

Epidemiology

Children
1. Most commonly affects ages 1 to 11 years old (peak age 1 to 4 years old)
2. More rapid spread associated with Atopic Dermatitis
Adolescents and Adults
1. Sexually Transmitted Infection
2. Significant outbreaks associated with HIV

Symptoms

Mild Pruritus may be present (often asymptomatic)

Signs

Characteristics
1. Discrete single or clustered lesions (<30 in group)
2. Raised, small firm dome-shaped Papules 3-5 mm diameter
3. Skin Colored or pearly white
4. Waxy-appearing
5. Central punctate umbilication
Distribution
1. Face
2. Trunk
3. Lower Abdomen
4. Extremities
  1. Rarely affects palms and soles
5. Pubis, inner thigh and genitalia (adults with STD)
6. Mucosa may be involved
7. Extensive involvement in HIV

Labs
Microscopy of Incision and Drainage material

Staining will show molluscum bodies
1. Wright's Stain
2. Giemsa Stain
3. Gram Stain

Management

General
1. Treatment is optional as these resolve on their own (over as long as 2-4 years)
  1. Avoid painful procedures for this benign, self-limited condition (especially in children)
  2. If treatment is desired, consider Aldara instead of Cryotherapy
  3. Treat those with Atopic Dermatitis or other underlying cause to prevent spread
2. Red and inflamed lesions are in the process of resolution
  1. Do not treat these lesions with cyrotherapy or Topical Medications
  2. Expect spontaneous resolution soon after inflammation appears
Cryotherapy
1. Consider Topical Anesthetic pretreatment in children
  1. Apply under Occlusion 15 to 30 minutes before
  2. Products
    1. EMLA
    2. ELA-Max
Electrodessication and Curettage (not recommended due to scarring risk)
1. Consider following curettage with application of:
  1. Iodine
  2. Trichloroacetic Acid 30%
Vesicant Application
1. Keratolytic Agents
2. Cantharidin
  1. YCanth
    1. Single use applicator of Cantharidin FDA approved for age >2 years (in 2023, approaches $700/applicator)
    2. Applied by medical provider every 3 weeks for 4 visits
    3. Clearance of molluscum in 3 months (NNT 3)
    4. (2023) Presc Lett 30(10): 58-9
3. Imiquimod 5% cream (Aldara; not FDA approved for molluscum)
  1. Preferred option by many dermatologists, although evidence of significant efficacy is lacking
  2. Apply to skin lesion for 6-10 hours, then wash off
  3. Apply 3 times weekly for 4 to 16 weeks
  4. Do not use on mucous membranes
Berdazimer (Zelsuvmi)
1. Applied daily for up to 12 weeks
HIV patients
1. Cidofovir has been used in advanced molluscum

Prevention

Molluscum contagiousum is contagious with direct skin contact
No school restrictions
Wrestling participation criteria
1. Active lesions must be covered with clothing or secure waterproof bandage

Course

Often spontaneously resolves without treatment
1. After 1 year: 50% of cases persist
2. After 2 years: 13% of cases persist
3. Some lesions may persist untreated as long as 2-4 years)
Conditions associated with severe Molluscum
1. HIV Infection
2. Other immunocompromising conditions
3. Atopic Dermatitis

Complications

Scarring may occur
Infammatory response to lesions (differentiate from secondary infection)
1. Local Inflammation (redness, swelling)
2. ID Reaction

References