Molluscum contagiosum (MC) is a common superficial viral infection of the epidermis that is most commonly seen in school-aged children.

In adults, MC occurs in patients who are immunocompromised due to HIV or immunosuppressive medications (chemotherapy or other) or in sexually active young adults as a sexually transmitted disease.

Although often a concern for parents of infected children, MC is rarely seen in immunocompetent adults.

The clinical presentations of MC in adults are discussed here. Detailed pathogenesis, clinical manifestations, and management of MC are presented in Chapter 6: Superficial Viral Infections.

MC lesions are dome-shaped, “waxy” or “pearly” appearing papules with a central white core or umbilication and most often appear on the face and eyelids (Figs. 17.17 and 17.18), the trunk, the axillae, the extremities (Fig. 17.19), and the genitalia. Number of lesions varies from one to hundreds.

Lesions spread by sexual contact are often seen on the external genitalia (Fig. 17.20), lower abdominal wall, inner thighs, and pubic area. When seen in these locations in young children, MC may be a sign of sexual abuse.

Immunocompromised patients present with “giant molluscum” consisting of coalescent double or triple lesions (Fig. 17.21). More than 100 lesions may be seen and are most commonly present on the face where they are spread by shaving. Such lesions are often chronic and are difficult to eradicate (discussed in Chapter 33: Cutaneous Manifestations of HIV Infection).

A shave biopsy is performed, if clinical appearance is not typical.

A short application of liquid nitrogen often accentuates the central core (Figs. 17.22A,B).