Molluscum Contagiosum

MOLLUSCUM CONTAGIOSUM, contagious mollusk (syn.: M. sebaceum, M. verrucosum, epithelioma contagiosum and others), a dermatosis first described in 1827 by Bateman; according to most authors, of infectious nature; more commonly observed in children and young people of both sexes in the form of hemispherical elevations with a central umbilical depression and one or two openings in the center, from which upon squeezing the mollusk from the sides, a pasty content, the so-called molluscum bodies, is discharged; individual elements ranging in size from a pinhead to a large pea, pale pink in color or the color of normal skin, are located mainly on the face and genitalia and occur in various quantities, without causing subjective sensations.-Etiology and pathogenesis. The contagious nature of the disease is confirmed by established facts of transmission of M. c. from one person to another: in several members of the same family, in a group of pupils of the same school or orphanage. Juliusberg and a number of other authors experimentally induced M. c. in humans by means of intradermal injections of a filtrate (through a Berkefeld candle) from M. c; incubation period from 15 days to several months. Experimental transmission of M. c. from humans to animals has not been successful. The causative agent is not precisely known. According to Lipschütz, these are the smallest round bodies, 1/4 the size of a red blood cell, found in enormous quantities in smears and sections of M. c. and intensely staining by Giemsa and Leffler; he calls them Strongyloplasma hominis and classifies them in the group of filterable viruses of epidermal nature. Some authors suggest that head and pubic lice may play the role of intermediate hosts. Darier considers molluscum bodies to be the result of dyskeratosis, i.e., improper cornification of epidermoid cells.-Pathological anatomy. On histological sections, the general picture resembles a cross-section of an orange; the tumor consists of separate fairly regular lobules of epidermis, which with their narrow ends are directed toward the umbilical depression. Changes in the cells increase in the direction from the basal to the keratohyalin layer and consist of the following: in the protoplasm, round or ovoid bodies appear, which, gradually increasing, displace the cell nucleus to the periphery; in the more superficial layers of the epidermis, the cell protoplasm disappears, and the mentioned bodies merge into a large formation, the molluscum body, filling the entire cell. According to Darier, the cells undergo "either eleidin keratinization or specific degeneration, transforming them into oval-shaped molluscum bodies that give colloidal or keratoid reactions". Clinical signs, and course. Arising without subjective sensations, the elements of M. c. in individual cases can reach large sizes (mol. cont. giganteum); remaining mostly flat, they sometimes take on a verrucous character; in some cases, the elements seem to be on a stalk (these forms need to be distinguished from mollusca pendula; see Fibroma). In the presence of irritation, mollusks can become inflamed and suppurate. Localized mainly on the face and genitalia, M. c. can however be located on any areas of the body, on the red border of the lips and even on the oral mucosa. In rare cases, the number of elements can reach several hundred; they are always located in isolation.-The prognosis is favorable due to the relatively easy curability of the dermatosis. Taking into account the contagiousness of M. c., it is necessary to subject each case immediately to treatment, which consists either in scraping with a sharp spoon or in cauterization with tincture of iodine, chromic or carbolic acid; in case of localization in the mouth, on the edges of the lips, eyelids, as well as with significant dissemination of M. c. elements, some authors use X-rays.-According to some authors, M. c. in humans is related to epithelioma contagiosum of birds. Mariani and others found similarity in the histological picture of M. c. in humans and birds. Lipschütz believes that in both diseases, it is a matter of related causative agents (from the Zyto-oikon group). Other researchers, based mainly on experimental data, do not find it possible to consider not only identical but even closely related to each other M. c. in humans and birds.