Molluscum contagiosum

Molluscum contagiosum

Chris Schach

Author Bio -

Key Points
*Common skin infection typically affecting children (toddlers to mid grade school age) but also occasionally young adults
*Consists of groups of rounded bumps, which are small, waxy and flesh colored to pink in color
*Harmless; eventually resolves even without treatment

Molluscum contagiosum virus, a member of the pox virus family, is easily transmitted from person to person, and also from place to place on the same individual.  After an incubation period lasting a few weeks to a few months, the virus will cause the formation of 1-4mm flesh colored to pink bumps (papules), many with a central depression (umbilication). Any area can be infected, but lesions are often seen on opposing surfaces of the skin where the virus may easily spread in a process called "autoinoculation". Examples include the inside of the upper arm and the thorax (side), and on the inside of each thigh. Individual lesions may come and go during the infection, but on the average all of the papules will resolve within months to 1-2 years. As with all benign (noncancerous) growths, treatment is optional. The virus can be spread by sexual contact in young adults, and in this situation, the molluscum will appear on the groin area or the lower stomach. As the condition clears, there may be inflammation in the affected area, accompanied by scabbing and crusting. Molluscum may number from a few to hundreds. In persons with compromised immune function, such as with HIV infection, the lesions may appear atypical and can be more difficult to recognize.  The presence of some underlying skin conditions, especially atopic dermatitis, may lead to increased numbers of molluscum. 


Differential Diagnosis (Other conditions with similar appearance)

Verruca plana (planar or flat warts)
Lichen Planus
Fibrous papule or syringoma (facial lesions)
Basal cell carcinoma

When occuring in persons with depressed immune function, molluscum may be large and can be confused with:
Cryptococcosis or coccidiomycosis
Genital warts

    Key Points
    *Diagnosis based primarily upon clinical recognition (appearance). 
    *Rarely, a skin biopsy may be necessary if there is an unusual appearance in an immunocompromised patient.


    *Treatment depends on the wishes of the parent or patient
    *Treatment, when requested, consists of destruction of lesions or use of topical immune stimulants or irritants

    Destructive methods your physician may offer include the use of liquid nitrogen (cryotherapy), curettage (scraping off the surface of the skin with a sharp instrument), application of a blistering agent (cantharidin), or application of other medications including potassium hydroxide, trichloroacetic acid, or concentrated alpha or beta hydroxy acids.

    Imiquimod or tretinoin may be prescribed for in-home use.

    Sometimes, the removal of the central "core" with a toothpick or duct tape may result in reolution of individual lesions.

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