Molluscum contagiosum. Light micrograph of a section through human skin infected with the viral disease molluscum contagiosum. This viral infection causes nodules on the skin's surface. This is a close-up of the bottom of a dome-shaped nodule embedded in the skin. Viral inclusion bodies (round) are at lower centre and across top, in the folds of the epidermis. The virus is spread via skin-to-skin contact and used to be most common in children. However, it is increasingly becoming a sexually transmitted disease. The disease often clears up on its own, although the nodules may be removed, either surgically or with chemicals, to prevent spread.