molluscum contagiosum

Introduction

Self-limited viral infection of the skin.

Etiology

• molluscum contagiosum virus, types 1 & 2 (poxvirus)
• spread is probably by direct contact (contagious) & by fomites (towels)

Epidemiology

• children & sexually active adults
  • up to 11% of children < 16 years of age
• increased incidence is observed in AIDS patients
• males > females

Pathology

• epidermal cells contain intracytoplasmic inclusion bodies (molluscum bodies or Henderson-Patterson bodies)
• epidermis grows down into the dermis
• epithelium and hair follicles also infected
• larger lesions may extend through the dermis to the subcutaneous fat

Clinical manifestations

• small lobular bodies on the mucosa of the lips & eyelids
• lesions may occur anywhere on the body
  • except, does not occur on the palms or soles
• lesions appear as pearly flesh-colored, small, round or oval papules (1-2 mm) or nodules 2-10 mm in diameter with central umbilication
• NOT associated with telangiectasias or bleeding
• painless, rarely pruritic (case with pruritic lesions)
• develop in crops & resolve over a period of weeks to several years
• lesions in sexually active adults are frequently observed in genital regions
• AIDS patients
  • may have hundreds of lesions on the face
  • spontaneous regression does not occur
• no regional lymph node involvement

* images

Laboratory

• biopsy if indicated
• examination under microscope, can not be cultured
• screening for HIV1 (adults)

Complications

• rarely causes serious complications
• dyspigmentation, scarring
• can exacerbate eczema
• psychosocial distress, frustration for parents

Differential diagnosis

• multiple small mollusca
  • flat warts
  • condyloma acuminata
  • syringoma
  • sebaceous hyperplasia
• solitary large mollusca
  • keratoacanthoma
  • squamous cell carcinoma
    • regional lymph node involvement with metastatic disease
  • basal cell carcinoma
  • epidermal inclusion cyst
• multiple facial mollusca in AIDS patient
  • cryptococcosis
  • histoplasmosis
  • coccidioidomycosis

Management

• generally resolves spontaneously within weeks to several years except in patients with HIV1 infection
  • ~50% of cases resolve in 1 year
  • observation is 1st line
• lesions can be removed by curettage
• cryotherapy with liquid nitrogen
• electrodesiccation for lesions refractory to cryotherapy
  • local lidocaine anesthesia
  • may require several cycles of electrodesiccation combined with curretage for larger lesions
• cantharidin (Ycanth) applied sparingly to non genital lesions
• berdazimer gel (Zelsuvmi) FDA-approved for at home use
• prevention: avoid skin to skin contact with infected individual
  • infection is contagious

More general terms

• viral infection
• sexually-transmitted disease

Additional terms

• molluscum body; Henderson-Patterson body
• Molluscum contagiosum virus