Контагиозный моллюск: симптомы, диагностика и лечение.

Viral infection of the skin

Molluscum contagiosum lesions are flesh colored, dome shaped, and pearly in appearance. They are often 1–5 mm in diameter, with a dimpled center. Molluscum lesions are most commonly found on the face, arms, legs, torso, and armpits in children. Adults typically have molluscum lesions in the genital region and this is considered to be a sexually transmitted infection; because of this, if genital lesions are found on a child, sexual abuse should be suspected. In some cases, eczema develops around the lesions. Individual molluscum lesions may go away on their own within two months and generally clear completely without treatment or scarring in six to twelve months. to about 18 months, but durations are reported as widely as six months to five years, lasting longer in immunosuppressed individuals. The viral infection is limited to a localized area on the topmost layer of the superficial layer of the skin. Once the virus containing head of the lesion has been destroyed, the infection is gone. The central waxy core contains the virus.

Diagnosis is made on the appearance; the virus cannot routinely be cultured. The diagnosis can be confirmed by excisional biopsy. Histologically, molluscum contagiosum is characterized by molluscum bodies (also known as Henderson Patterson bodies) in the epidermis, above the stratum basale, which consist of cells with abundant large granular eosinophilic cytoplasmic inclusion bodies (accumulated virions) and a small nucleus that has been pushed to the periphery.

Because molluscum contagiosum usually resolves without treatment and treatment options can cause discomfort to children, initial recommendations are often to simply wait for the lesions to resolve on their own. Of the treatments available, a meta analysis of randomized controlled trials suggested that there is no difference between treatments in short term improvement, and no single treatment is significantly better than natural resolution of the condition. Bumps located in the genital area may be treated in an effort to prevent them from spreading. Studies have found cantharidin to be an effective and safe treatment for removing molluscum contagiosum. There is no high quality evidence for cimetidine. However, oral cimetidine has been used as an alternative treatment for the pediatric population as it is generally well tolerated and less invasive.

Imiquimod is a form of immunotherapy initially proposed as a treatment for molluscum based on promising results in small case series and clinical trials. However, two large randomized controlled trials, specifically requested by the U. S. Food and Drug Administration under the Best Pharmaceuticals for Children Act both demonstrated that imiquimod cream applied three times per week was no more effective than placebo cream for treating molluscum after 18 weeks of treatment in a total of 702 children aged 2–12 years. In 2007, results from those trials—which remain unpublished—were incorporated into FDA approved prescribing information for imiquimod, which states: "Limitations of Use: Efficacy was not demonstrated for molluscum contagiosum in children aged 2–12." In 2007, the FDA also updated imiquimod's label concerning safety issues raised in the two large trials and an FDA requested pharmacokinetic study (the latter of which was published).

Surgical treatments include cryosurgery, in which liquid nitrogen is used to freeze and destroy lesions, as well as scraping them off with a curette. Application of liquid nitrogen may cause burning or stinging at the treated site, which may persist for a few minutes after the treatment. With liquid nitrogen, a blister may form at the treatment site, but it will slough off in two to four weeks. Cryosurgery and curette scraping can be painful procedures and can result in residual scarring.

A 2014 systematic review of case reports and case series concluded that the limited available data suggest pulsed dye laser therapy is a safe and effective treatment for molluscum contagiosum and is generally well tolerated by children.

Most cases of molluscum contagiosum will clear up naturally within two years (usually within nine months). So long as the skin growths are present, there is a possibility of transmitting the infection to another person. When the growths are gone, the possibility of spreading the infection is ended. Unlike herpesviruses, which can remain inactive in the body for months or years before reappearing, molluscum contagiosum does not remain in the body when the growths are gone from the skin and will not reappear on their own.

As of 2010, approximately 122 million people were affected worldwide by molluscum contagiosum (1.8% of the population).