Contagious mollusk

The disease is caused by four types of Molluscum contagiosum virus, or MCV, a DNA virus of the Poxviridae family. Of these, MCV1 is most common in pediatric-age individuals in whom it goes on to affect the face, limbs and trunk. Type MCV2 is the rarest of the four, is mainly observed in adults and is sexually transmitted. Specifically, it causes an infection that usually affects the skin and mucous membranes without involving the internal genitalia; the buttocks and perianal region can also be affected. MCV3 and MCV4 types are prevalent in Asia and Australia.

Transmission is by direct contact with the skin or mucous membranes of an infected person, and spread is by autoinoculation (e.g., through towels). Regardless of the point of entry of the virus, lesions can also reach other parts of the body.
This disease is typical upon return from travel and vacations because, beyond sexual intercourse, it is easily contracted through contact with contaminated surfaces such as swimming pools, saunas, gymnasium seats, and beauty salon beds.

Because the disease is not very dangerous and is therefore not reported by patients, we do not have firm data on its incidence.
What we do know is that it is an extremely common disease, widespread throughout the world and whose spread is facilitated in warm climates. Some studies suggest that it has an incidence of 2.6 percent, with 80 percent of cases identified in children under 15 years of age, particularly in the 1- to 4-year-old range.
In general, the incidence of molluscum contagiosum increases almost threefold in countries with warm or tropical climates and lower socioeconomic and hygienic standards than in Europe.

The infection has an incubation time that lasts between 15 days and 6 months, at the end of which clustered lesions develop, dome-shaped papules with a diameter usually ranging from 2 to 5 mm and never affecting the palms of the hands or soles of the feet.
Molluscum contagiosum lesions normally do not itch or are painful, but may develop inflammation with itching when the immune response toward the virus begins.
In patients with immune problems, the papules are very numerous and up to 1 cm in diameter and tend to resist treatment. In the area peripheral to the affected skin, contagious eczema or molluscum may be observed.
In case the eyelids are affected, superficial punctate keratitis or even chronic conjunctivitis may occur.
As for children, this Poxvirus is more frequent in those with atopic eczema, because such a condition with intense itching causes scratching and papules are present in the affected sites.
Molluscum contagiosum tends to resolve spontaneously but the infection must still be treated, both to mitigate its spread and to anticipate its cessation.tc.

Diagnosis in general is based on a search for papules.
If the diagnosis is doubtful, the presence of Molluscum contagiosum can be confirmed by a tissue biopsy, examining the papules under an electron microscope; antibody serologic testing is not recommended because it is not very reliable.

The choice of therapy to treat lesions of this Poxvirus depends on various factors, including the age of the subject, the immune status, and the number and site of papules. A first approach involves destruction of the lesions and can develop in two ways:

• chemical: potassium hydroxide 10%, silver nitrate 40%, cantharidin 0.7 in collodion.
• Physical: curettage, cryotherapy.

There is then pharmacological treatment through salicylic acid, podophyllotoxin (an antiviral also used for genital warts) and tretinoin (acid form of vitamin A with keratolytic-like action). Also worth mentioning is the active ingredient Imiquimod, which is also used for the treatment of condylomata acuminata as well as basal cell carcinomas or basaliomas and actinic keratoses. The dosage of this immunomodulatory drug should be indicated on an individual basis. Imiquimod is a modifier of the immune response, acting locally to bring about the release of cytokines that promote elimination of Poxvirus. After treatment for Poxvirus papules, recurrences can frequently occur, also favored by xerosis (dryness) of the skin apt to stimulate scratching. Prompt specialist examination is always advisable to decrease the risk of self-infection following scratching or to avoid transmission to others. The intervention of a dermatologist will promote with the right therapy faster healing, through topical preparations, cryotherapy with liquid nitrogen or by scraping the lesions (curettage).

As a preventive measure, it is important to always keep in mind the use of condoms during sexual intercourse to avoid lesions that can be localized to the shaft of the penis (it does not, of course, protect against the risk to other pubic sites). If necessary, one can assess the partner with careful observation at the genital level for recognition of any papules or otherwise reddish or pearly "bumps."
It is also good to avoid sharing towels, wipes, underwear and if possible avoid contact sports.
To avoid infection in pediatric-aged individuals, it is also recommended to avoid crushing or breaking the lesions so as not to increase the risk of spread to other body areas.