Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 6-38: Molluscum Contagiosum + Key Features Download Section PDF Listen +++ ++ Caused by a poxvirus The lesions are autoinoculable and spread by wet skin-to-skin contact In sexually active individuals, lesions may be confined to the penis, pubis, and inner thighs and are considered a sexually transmitted infection Common in AIDS patients Usually with a helper T cell count < 100/mcL Extensive lesions tend to develop over the face and neck as well as in the genital area Lesions are difficult to eradicate unless immunity improves, in which case spontaneous clearing may occur + Clinical Findings Download Section PDF Listen +++ ++ Presents as single or multiple, dome-shaped, waxy papules 2–5 mm in diameter that are umbilicated Lesions at first are firm, solid, and flesh colored but on reaching maturity become soft, whitish, or pearly gray and may suppurate The principal sites are the face, lower abdomen, and genitals Individual lesions persist for about 2 months + Diagnosis Download Section PDF Listen +++ ++ Clinical; based on the distinctive central umbilication of the dome-shaped lesion Differential diagnosis Warts Varicella (chickenpox) Basal cell carcinoma Lichen planus Smallpox Cutaneous cryptococcosis (in AIDS) + Treatment Download Section PDF Listen +++ ++ The best treatment is by curettage or applications of liquid nitrogen as for warts but more briefly When lesions are frozen, the central umbilication often becomes more apparent Light electrosurgery with a fine needle is also effective Cantharidin (applied in the office and then washed off by the patient 4 hours later) is a safe and effective option Other treatment options Potassium hydroxide 10% solution applied twice daily until lesions clear Salicylic acid Podophyllotoxin Tretinoin Imiquimod Pulsed dye laser Comedone extractor or currette