Causes
- Molluscum contagiosum is a poxvirus infection of the skin
- Transmission is via direct skin-to-skin contact
- Autoinoculation is common especially with scratching, areas of dermatitis or friction
Clinical presentation
Typically presents as benign spontaneously resolving, painless infection lasting months and occasionally up to 2 years.
Common in young children, where lesions occur anywhere on the body (including the genitals), especially in skin folds.
In adults, it can be seen as a sexually acquired infection affecting the genitals, pubic region, lower abdomen, upper thighs and/or buttocks.
In HIV infection and other immunosuppressive conditions, lesions may be widespread and atypical.
Those with atopic dermatitis may also have disseminated molluscum.
The opportunity to screen for other STIs should be taken as genital molluscum may be a marker of risk for sexually transmissible infections.
This should include testing for HIV, especially where lesions are multiple and widespread, large, or seen on the face.
Diagnosis
Clinical diagnosis where no specific investigations are indicated:
- lesions are usually multiple and occur in clusters, presenting as smooth-surfaced, firm, dome-shaped papules with central umbilication
- lesions are found on keratinised skin, especially skin folds and hair bearing areas, and can affect almost any part of the body
Genital molluscum may be confused with ectopic sebaceous glands, and patients may confuse lesions with genital warts.
Localised redness and soreness may be due to secondary bacterial infection. Redness also occurs prior to natural resolution.
Approximately 10% of adults develop eczema around lesions that resolves as the lesions regress.
Management
| Condition | Recommended | Comments |
|---|---|---|
| Molluscum in immunocompetent patients | No treatment is reasonable |
Molluscum infection resolves naturally, usually leaving no long-term sequelae. Untreated, lesions can persist for 6 months to 2 years. Most individual lesions clear by 3 months. Some treatments may shorten the disease course, but this should be balanced against possible side-effects and patients should be warned that new lesions may continue to erupt. Patients should be educated about risks of autoinoculation and advised against shaving, waxing or scratching their genital regions, to prevent further spread of lesions, secondary infection and scarring. Transmission to others may be minimised by covering lesions where possible and avoiding sharing towels and bedding. |
| Physical treatment for molluscum | Cryotherapy with liquid nitrogen cryospray until a halo of ice surrounds the lesion |
Repeat treatments may be performed weekly until resolution. Other destructive treatments such as piercing with a sterile 19-gauge needle with expression of the pearly core and application of tincture of iodine or phenol, or diathermy/curettage under local anaesthesia are seldom performed owing to issues of pain and potential scarring. |
| Topical treatment for molluscum |
Podophyllotoxin 0.5% cream or paint twice daily for 3 days per week for 4 weeks OR Imiquimod 5% applied sparingly 3 times per week for up to 16 weeks has shown some limited efficacy. |
Podophyllotoxin and imiquimod should be avoided in pregnancy and breastfeeding. |
| Immunosuppressed patients | Seek specialist advice | Immunosuppressed patients and people living with HIV may require input from a sexual health physician, infectious diseases specialist or dermatologist for systemic treatments where the above treatments have failed or lesions are large or extensive. |
Disclaimer
We recognise that gender identity is fluid. In our treatment guidelines, the words and language we use to describe genitals and gender are based on the sex assigned at birth.
The content of these treatment guidelines is for information purposes only. The treatment guidelines are generic in character and should be applied to individuals only as deemed appropriate by the treating practitioner on a case by case basis. Alfred Health, through MSHC, does not accept liability to any person for the information or advice (or the use of such information or advice) which is provided through these treatment guidelines.
The information contained within these treatment guidelines is provided on the basis that all persons accessing the treatment guidelines undertake responsibility for assessing the relevance and accuracy of the content and its suitability for a particular patient. Responsible use of these guidelines requires that the prescriber is familiar with contraindications and precautions relevant to the various pharmaceutical agents recommended herein.