Molluscum contagiosum

Created 2009.

Learning objectives

Identify and manage molluscum contagiosum

Clinical features

Molluscum contagiosum is a common cutaneous infection due a pox virus. It mainly presents in childhood as multiple soft umbilicated papules. Thick white material can be expressed from the middle of the papules. They are often clustered in the flexures especially axillae and genital areas.

Molluscum contagiosum often provokes localised eczema, particularly in atopic children.

As the lesions resolve the papules may become inflamed (red and crusted) or necrotic (black scabs) and may leave punctate scars.

Untreated, the papules resolve after a few months. They rarely persist for longer than two years.

Molluscum contagiosum

Investigations

In general, no investigations are necessary and the diagnosis is made clinically. However, a skin biopsy may be helpful. Characteristic features are:

Epidermal hyperplasia
Central crater filled with molluscum bodies (huge eosinophilic to basophilic intracytoplasmic inclusions)
No inflammation in intact lesions; dense inflammatory response in ruptured lesions

Management

Treatment may not be necessary or advisable in the majority of young children. Options include:

Emollients and mild topical steroids (usually hydrocortisone cream) to reduce itching and eczema
In older children or adults the lesions can be removed individually. Methods include:
- Expressing lesion contents using forceps
- Curettage after EMLA application
- Prick out the centre with a sharp stick
- Light cryotherapy
- Cantharidine solution, covered with a plaster and washed off 2-4 hours later
- Imiquimod cream, applied three times weekly for four weeks or so