A 26-year-old woman comes to the office due to a skin lesion on her thigh that appeared approximately 3 weeks ago. The patient does not have a history of similar lesions. She has mild pruritus but no fever, chills, or pain. The patient has no chronic medical conditions and takes no medication. She is sexually active. Examination of the leg and a close-up of the lesion are shown in the Image 1, Image 2. Which of the following is the most appropriate next step in management?
Molluscum contagiosum | ||
Children | Adults | |
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STI = sexually transmitted infection. | ||
Molluscum contagiosum (MC) is a benign poxvirus infection spread via skin-to-skin contact (eg, sexual activity, contact sports) or contaminated fomites (eg, washcloths). Examination of MC shows small, firm, skin-colored papules with indented centers that may be isolated, clustered, or widely scattered due to autoinoculation. An amorphous yellow center may be visualized with dermatoscopy. Pruritus and inflammation may or may not be present. In adults, the lesions classically occur on the lower abdomen, genitalia, and upper thighs in adults, reflective of the most common route of exposure in this population, which is sexual contact. However, they may develop anywhere on the body except the palms and soles.
The diagnosis of MC is clinical, and no further diagnostic evaluation is required (Choice A). However, patients with widespread or persistent lesions should undergo HIV testing because HIV infection is associated with a prolonged course. In addition, adolescents and adults with MC of the genital area should undergo additional screening for sexually transmitted infections (STIs).
Although lesions typically self-resolve in 6-12 months, treatment is recommended in adults to prevent transmission to others and autoinoculation. First-line therapy of MC in adults includes cryotherapy with liquid nitrogen, curettage, or topical therapy (eg, cantharidin). Cryotherapy is typically well tolerated in adults, with nearly complete resolution of lesions within weeks.
(Choice C) The diagnosis of MC is often clinical; dermoscopy can sometimes be used to support the diagnosis (eg, central umbilication, polylobular amorphous structures), and biopsy is not typically required. Biopsy can confirm nodular basal cell carcinoma, which can present as an isolated papule but typically is associated with a telangiectatic vessel, develops at a more advanced age, and is more common in sun-exposed areas (eg, 80% on face and hands).
(Choice D) Rapid plasma reagin (RPR) screens for syphilis, which can present with condyloma lata, or raised white lesions on mucosal surfaces (eg, mouth, genitalia). In addition, screening for STIs (eg, RPR) is recommended for genital MC. However, this patient's isolated, rounded papule on her lower extremity is not suggestive of syphilis and requires no further evaluation.
(Choice E) Topical acyclovir can treat herpes simplex virus, which causes grouped, erythematous vesicles that evolve into painful ulcerations. In contrast, this patient has an isolated, nonpainful, flesh-colored lesion.
(Choice F) Localized dermatitis often develops near MC lesions, and topical corticosteroids (eg, triamcinolone) can treat associated pruritus and inflammation. However, these medications do not play a role in asymptomatic MC and are not associated with clearance of the underlying virus.
Educational objective:
Molluscum contagiosum is a benign condition characterized by small papules with central umbilication. First-line therapy in adults includes cryotherapy with liquid nitrogen, curettage, or topical therapies (eg, cantharidin).