Molluscum contagiosum

Snapshot

A 3-year-old girl presents to her pediatrician’s office with several pink spots on her body. Her parents report that she seems mostly unbothered by these lesions but occasionally scratches at them. Several of her friends have similar lesions. On physical exam, there are several 2-3 mm flesh-colored papules with central umbilication. Her pediatrician counsels them that this viral infection is benign and self-resolves. However, if the lesions seem to bother the patient, then there are treatment options such as cryotherapy or topical cantharidin.

Introduction

Clinical definition
- painless and umbilicated cutaneous lesions caused by the molluscum contagiosum virus
Epidemiology
- incidence
  - up to 30% in patients with HIV
- demographics
  - school-aged children
    - most common
    - the children are typically immunocompetent
  - adolescents and young adults
    - transmitted via sexual contact and can present as genital lesions
  - immunocompromised individuals
    - transmitted via physical or sexual contact
- risk factors
  - atopic dermatitis
  - immunocompromised states
Etiology
- molluscum contagiosum virus
  - an enveloped DNA poxvirus
Pathogenesis
- the molluscum contagiousum virus is transmitted via
  - autoinoculation
  - physical and sexual contact from an infected person
- after the virus invades epidermal cells, it proliferates and creates lobulated epidermal growths
Associated conditions
- if patient has genital molluscum
  - other sexually transmitted infections may be found
- in adults
  - may be an indicator of HIV
Prognosis
- lesions resolve spontaneously within 9 months
no scarring

Presentation

Symptoms
- primary symptoms
  - usually asymptomatic
  - may have pruritus and/or tenderness
Physical exam
- immunocompetent patients
  - single or grouped lesions
  - .1-1 cm papules with central umbilication
    - pearly
    - flesh-colored
  - location
    - trunk
    - extremities
    - head
    - neck
    - genitals
- immunocompromised patients
  - > 30 lesions
  - > 1 cm lesions
lesions on the eyelid

Studies

Dermatoscope exam
- central umbilication
Biopsy
- indication
  - confirms the diagnosis when it is clinically uncertain
Histology
- molluscum bodies
  - Henderson-Patterson bodies
  - large cells with granular eosinophilic cytoplasm that contain accumulated virons
Making the diagnosis
a clinical diagnosis

Differential

Treatment

Management approach
- treatment is usually not necessary as lesions resolve within 6-9 months
- multiple first-line therapies are available and chosen based on shared-decision making by the physician and the patient or the patient’s family
Medical
- cryotherapy
  - indications
    - well tolerated in adolescents and adults
    - can be too painful for young children, especially with multiple lesions
- topical podophyllotoxin 0.5% cream
  - indication
    - ideal for genital lesions
- cantharidin
  - indication
    - treatment is applied topically in the office and blistering occurs hours later
    - ideal for children with multiple lesions
Operative
- curretage
  - indication
    - well tolerated in adolescents and adults
    - can be too painful for young children, especially with multiple lesions
ideal for those who wish for more immediate resolution

Complications