Molluscum ContagiosumOverview

Molluscum contagiosum (MC) is a benign viral disease of the skin caused by molluscum contagiosum virus (MCV) a member of the poxvirus group that affects both children and adults. This common viral disease is confined to the skin and mucous membranes. It frequently appears on the face, neck, arm pit, arms, and hands but may occur anywhere on the body except the palms and soles. There are 4 types of MCV, MCV-1 having the highest prevalence and MCV-2 usually seen in adults and often sexually transmitted.
Molluscum contagiosum is transmitted through direct skin contact with an infected person, saliva and shared articles of clothing (including towels, tattoo instruments, and in beauty parlors and Turkish baths). In adults, it is often sexually transmitted and usually appears on the genitalia, lower abdomen, buttocks, and inner thighs and rarely on the lips and mouth. The early lesions on the genitalia are often mistaken for genital herpes or warts, but unlike these the lesions are painless. Molluscum contagiosum doesn't cause any serious illness, which is why it is not treated as other sexually transmitted diseases. The importance is significant in immunocompromised persons with AIDS, who may have rapidly worse case of molluscum contagiosum.
Molluscum contagiosum can be found worldwide, with a higher incidence in the tropical areas, although fairly high incidences have been documented in northern European countries as well. The worldwide incidence is estimated to be between 2% and 8%.
MC is a common infection throughout the United States, accounting for approximately 1% of all diagnoses of skin disorders. The exact incidence in the United States is unknown. There is a higher incidence in children with eczema as well as in immunocompromised individuals.
Molluscum has an average incubation period of 2 to 7 weeks and even up to 6 months.

SIGNS AND SYMPTOMS

Physical symptoms are generally limited to the skin, but there have been cases when the primary lesions appeared also on the eyelids and conjunctiva.
The primary lesions appear as firm, smooth, umbilicated, painless papules, usually 2-6 mm in diameter (range 1-15 mm), in groups or widely disseminated on the skin and mucosal surfaces. These papules may occur in lines, where the person has scratched. Scratching or other irritation causes the virus to spread in a line or in groups (crops). They are generally skin coloured, white, translucent, or even yellow in colour with an opalescent character. The central depression or umbilication (dimple) contains a white, waxy curdlike core. In immunocompromised persons, the lesions are more widespread and can be as large as 10-15 mm in diameter. The number of lesions varies from 1-20 up to hundreds in some reports and may appear anywhere, but they have a predilection for the face, trunk, and extremities in children and for the groin and genitalia in adults.
Molluscum contagiosum is a chronic infection and lesions may persist from a few months to a few years. These lesions ultimately disappear without scarring.

TREATMENT

There have been few well-controlled studies of compounds that may be beneficial in the treatment of molluscum contagiosum. Since the disease tends to go away on its own in six to nine months, invasive or toxic treatments are generally not indicated. More aggressive treatments, such as antivirals, may be required for immunocompromised patients.
Health professionals usually recommend treating bumps located in the genital area to prevent them from spreading. The main therapy for immunocompetent persons is destruction of the lesions with a variety of chemical and physical agents such as cantharidin (a vesicant) and cryotherapy with liquid nitrogen (freezing). Another treatment option is curettage but is more painful and more likely to leave scars. Other treatments include salicylic acid, tretinoin gel 0.01%, silver nitrate, phenol, and trichloroacetic acid, Cimetidine (Tagamet), antiviral drugs such as Cidofovir (Vistide), Cytotoxic agents such as Podophyllum resin (Pod-Ben-25, Podocon-25).

COMPLICATIONS

Molluscum contagiosum usually causes no health related issues. Nevertheless, it is possible that the infection will last for a lengthy amount of time. MC can also lead to bacterial superinfections with Staphylococcus aureus, Staphylococcus epidermidis or Streptococcus species. It can also be auto inoculated to other parts of the body by scratching and it can lead to extensive infections in immunocompromised individuals.

PREVENTION

Limiting physical contact with infected individuals and improving personal hygiene should reduce transmission and autoinoculation of the virus. Safe sex practices and/or abstinence should be discussed, although it is unclear whether condoms and other barrier methods provide adequate protection against the transmission of molluscum contagiosum.

References

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