Molluscum contagiosum

Contagious molluscum is a chronic viral dermatosis, which is observed mainly in children; this is a viral disease, characterized by the appearance on the skin of hemispherical nodules with a central impression, visually resembling shells of mollusks.

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Causes of the molluscum contagiosum

What causes a molluscum contagiosum?

The causative agent of the disease is the molluscus contagiosum virus, which is considered to be pathogenic only to humans and transmitted either through direct contact (in adults - often with sexual intercourse) or mediated by the use of general hygiene items (loofers, sponges, towels, etc.).

The incubation period ranges from several to several months. Sometimes the disease occurs in people with reduced immunity, severe systemic diseases.

The virus (MCV) is not a classifiable type of smallpox virus. The disease is found everywhere and affects only people. Infection is transmitted by direct (everyday or sexual) contact with a sick person or indirectly - through household items. Children under one year are ill rarely, probably because of the immunity acquired from the mother and a long incubation period.

According to numerous observations, molluscum contagiosum is more common in patients suffering from atopic dermatitis and eczema. This is due to both a decrease in the reactivity of the skin, and long-term use of topical steroids. Extremely widespread rashes were noted in patients with sarcoidosis, in patients receiving immunosuppressive therapy, as well as in HIV-infected patients. Thus, cell-mediated immunity is of great importance in the emergence and development of the infectious process.

Pathogenesis

How does a molluscum develop?

The links of pathogenesis have not been studied enough, but the decisive role is played by the disturbance of the epidermal growth factor. The virus is introduced into the keratinocytes of the basal layer of the epidermis and significantly increases the rate of cell division. Then in the spinous layer there is an active accumulation of viral DNA. As a result, a nodule is formed, at the center of which the destruction and destruction of epidermal cells occurs, while the cells of the basal layer are not affected. Thus, the central part of the node is represented by detritus containing hyaline bodies (mollusc bodies) with a diameter of about 25 microns, which in turn contain masses of viral material. Inflammatory changes in the dermis are minor or absent, but in the case of long-lasting elements can be represented by a chronic granulomatous infiltrate.

Symptoms of the molluscum contagiosum

How is a molluscum contagiosum manifested?

The molluscum contagiosum has an incubation period that ranges from 14 days to 6 months. The rashes are shiny pearly white hemispherical papules with an umbilical depression in the center. Slowly increasing in size, the papule can reach a diameter of 5-10 mm in 6-12 weeks. With a solitary lesion, the diameter of the papule reaches considerable dimensions. After a trauma or spontaneously, after a few months, the papules can get nagged and ulcerated. Usually, having survived 6-9 months, the spillage is spontaneously resolved, but some persist up to 3-4 years. Eruptions are localized more often on the face, neck, trunk, especially in the axillary region, except for sexually transmitted infection, when the anogenital area is usually affected. Elements can also be located on the scalp, on the lips, tongue, cheek mucosa, in any area of the skin, including atypical localization - the skin of the soles. Papules can be localized on scars, tattoos.

In the places of introduction of the virus there are single or multiple, dense, shiny, painless, pink or grayish-yellow nodules the size of millet grains to peas. In the center of the element there is a characteristic depression. In children, they are more often located on the face, neck, rear of the hands, can be randomly scattered throughout the skin cover or grouped into separate foci.

Contagious molluscum in children under 10 years is more often localized on the face. Here, rashes are often located on the eyelids, in particular, on the ciliary edge, around the eyes, on the nose and around it, on the cheeks, chin. In addition to the face, other areas are often affected, including the submaxillary, neck, chest, upper extremities, trunk, external genitalia, and others.

If in children frequent localization on the face (about 1/2 of all cases) is understandable and is a common occurrence, the molluscum contagiosum in adults is rarely located on the facial area and is considered as a result of weakened immunity (atopy, immunosuppressive therapy, AIDS, etc.). Adults are considered immune to the virus, so the rapid spread of it on the skin, especially on the face, as well as the appearance of atypical forms indicate the acquired immunodeficiency. In such cases, it is necessary to clarify the anamnesis, to conduct the necessary studies (including HIV infection) to determine the pathogenesis.

In typical cases, the primary elements of the rash are non-inflammatory, semi-translucent nodules, whitish-matte, corpulent from yellowish-pinkish, the size of a pinhead or millet. More often such elements are several, they are located in small groups, asymmetrically and do not cause subjective sensations. On small elements, there are no umbilical impressions in the center and they are very similar to miloons or young forms of flat warts. The number and size slowly increase, and they reach the average size of a pea. Such elements have hemispherical shape, characteristic deepening in the center, dense consistency. When the knot is squeezed from the sides by tweezers from the umbilical occlusion, a whitish, mushy mass is produced, consisting of horny epidermal cells, mollusc bodies and fat. This helps with clinical and microscopic diagnosis.

Clinical manifestations on the face can be very diverse and resemble some other similar in the manifestations of dermatosis. In addition to the above typical elements can occur and atypical of its form. In those cases where a single element reaches a value of 1 cm or more, a gigantic shape resembling a cyst is ascertained. Some elements (more often giant) ulcerate and resemble keratoacanthoma, ulceration of basal cell or squamous cell carcinoma of the skin. Individual elements can become inflamed and inflamed, so they change their appearance and become like acne (acneiform), chicken pox (varicelleform), folliculitis (folliculitis-like) or furuncle (furuncle-like). Such clinical forms present certain difficulties for diagnosis. The simultaneous presence and typical nodules facilitates the diagnosis. Suppuration usually ends with a spontaneous regress of this element.

In HIV-infected individuals, rashes are multiple, localized primarily on the face and resistant to conventional therapy.

In adults with sexual infection, rashes can be localized on the genitals and perigenital areas.

Characteristic for the nodules is the allocation of white mushy mass from the central groove of papules when squeezing them with tweezers. Subjective sensations are usually absent. Sometimes rashes can merge into large uneven tumor-like formations ("giant molluscum") or disappear spontaneously.

Histopathology

There is a characteristic formation consisting of pear-shaped lobules. Cells of the epidermis are enlarged, many intraplasmatic inclusions (mollusc bodies) that contain viral particles. In the dermis there is a small inflammatory infiltrate.

Diagnosis is based on a characteristic clinical picture. Verification of the diagnosis allows the detection of characteristic "mollusc bodies" when microscopically examining the mushy mass squeezed from the mollusk (brilliant when viewing a native preparation in a dark field of a microscope or blue-colored primary salvers, methylene blue or Romanovsky-Giemsa). In some cases, to clarify the diagnosis, a histological examination of the affected skin is performed.

Diagnostics of the molluscum contagiosum

How to recognize molluscum contagiosum?

On the face of children and young men molluscum contagiosum is primarily differentiated from flat warts, miloons, angiofibrom (isolated and symmetrical), syringoma, verruxiform epidermodysplasia, Darya's disease, trichoepithelioma, and atypical forms - from cysts, acne, varicellae, folliculitis, furuncle , barley.

In middle-aged and elderly people, in addition to the more rare for this group of the above dermatoses, a differential diagnosis of molluscum contagiosum is carried out with senile hyperplasia of the sebaceous glands, xanthelasma, papular xanthoma, nodular elastoidosis with cysts and comedones (Favre-Rakusho disease), hydrocystoma ), keratoacanthoma, ulcerated basal cell carcinoma or squamous cell carcinoma.

Treatment of the molluscum contagiosum

Molluscum contagiosum: treatment

Patients should avoid visiting swimming pools, common baths, carefully observe the rules of personal hygiene. Any cosmetic procedures are undesirable. Molluscum contagious treatment has no specific.

You can remove the molluscum contagiosum by epilating tweezers and scraping with a spoon, followed by lubricating the erosion with 1% alcohol solution of iodine. Prior to removal it is recommended (especially in children) local anesthesia with 10% lidocaine spray or short-term freezing with liquid nitrogen. Such treatment does not leave permanent traces. Diathermocoagulation, cryo- or laser degeneration on the face should be avoided, as they can leave scar changes. In young children, in some cases it is advisable to leave the elements without treatment or to limit themselves to prolonged external application of interferon ointment.

Patients (or parents of children) should be aware of possible relapses of the disease, therefore, all members of the family, as well as the patient, should be examined 2-3 weeks after completion of treatment, taking into account identified predisposing factors.

It is necessary to remove nodules from the Volkmann spoon, diathermocoagulation followed by lubrication with a 2-5% alcohol solution of iodine. Diathermocoagulation of elements is also possible. With disseminated forms of the disease, antiviral agents are used: proteflasite (15-20 drops 2 times a day for adults), interferon (3-4 drops in the nose 4-5 times a day) or metisazone inside.