Molluscum Contagiosum

 

Molluscum contagiosum (MC) is a viral infection of the skin or occasionally of the mucous membranes. It is caused by a DNA poxvirus called the molluscum contagiosum virus (MCV). MCV has no animal reservoir, infecting only humans. There are four types of MCV, MCV-1 to -4; MCV-1 is the most prevalent and MCV-2 is seen usually in adults and often sexually transmitted. This common viral disease has a higher incidence in children, sexually active adults, and those who are immunodeficient, and the infection is most common in children aged one to ten years old.MC can affect any area of the skin but is most common on the trunk of the body, arms, and legs. It is spread through direct contact or shared items such as clothing or towels.

The virus commonly spreads through skin-to-skin contact. This includes sexual contact or touching or scratching the bumps and then touching the skin. Handling objects that have the virus on them (fomites), such as a towel, can also lead to in infection. The virus can spread from one part of the body to another or to other people. The virus can be spread among children at day care or at school. Molluscum contagiosum is contagious until the bumps are gone-which, if untreated, could be up to 6 months or longer.

The time from infection to the appearance of lesions can range up to 6 months, with an average incubation period between 2 and 7 weeks.

Molluscum Contagiosum

 

Diagnosis is made on the clinical appearance; the virus cannot routinely be cultured. The diagnosis can be confirmed by excisional biopsy.

Histologically, molluscum contagiosum is characterized by molluscum bodies in the epidermis above the stratum basale, which consist of large cells with:

Molluscum contagiosum lesions are flesh-colored, dome-shaped, and pearly in appearance. They are often 1–5 millimeters in diameter, with a dimpled center. They are generally not painful, but they could itch or become irritated. Picking or scratching the bumps could lead to further infection or scarring. In about 10% of the cases, eczema develops around the lesions. They could occasionally be complicated by secondary bacterial infections. In some cases the dimpled section could bleed once or twice. The viral infection is limited to a localized area on the topmost layer of the epidermis. Once the virus containing head of the lesion has been destroyed, the infection is gone. The central waxy core contains the virus. In a process called autoinoculation, the virus could spread to neighboring skin areas. Children are particularly susceptible to auto-inoculation, and could have widespread clusters of lesions.