Molluscum contagiosum
Molluscum contagiosum (MC) is a large, brick-shaped, double-stranded DNA virus of the Poxiviridae family. The virus is transmitted primarily through sexual contact and fomite spread, typically affecting three distinct populations: children, sexually active adolescents, and the immunosuppressed. The distribution of MC is specific to each of the aforementioned population groups. In children, MC is seen on the face, trunk, and extremities, whereas in sexually active adolescents, genital lesions are the most common site of presentation. Unique to the immunocompromised HIV population, lesions are seen far more commonly on the head and neck, followed by the genitalia. As the most common pox virus pathogen in humans, MC deserves notable recognition. Though self-limited in the immunocompetent, MC has been recognized as causing significant morbidity and disfigurement among a burgeoning immunocompromised population.
Defined by its specific pathogenicity in humans and its nearly exclusive cutaneous involvement, MC is rarely associated with other skin lesions and usually displays distinctive clinical and cytopathologic features. Fully developed MC may present as solitary or multiple umbilicated papules expressing white keratinous material. It has been reported that up to 4% of MC cases have been seen in association with other lesions.
Purple penile papules. Am J Dermatopathol. 2007 29 (4): 417-418
Tags: Biology, Health, Medicine, Microbiology, Science, Virology
[...] by ajcann on November 28, 2007 Poxviruses are large DNA viruses that cause human smallpox and molluscum contagiosum in addition to several zoonoses. They are distinguished from other DNA viruses by replicating [...]