A 22-year-old man comes to the office due to skin lesions. The patient noticed a nonpainful, nonpruritic skin bump on his right knee 3 months ago, which progressively increased in size and number. He has no prior health issues and takes no medications. The patient is outdoors frequently for work and recreational activities. He is sexually active. Physical examination findings are shown in the exhibit.
Which of the following microbial organisms is most likely responsible for this patient's current condition?

Question

A 22-year-old man comes to the office due to skin lesions.  The patient noticed a nonpainful, nonpruritic skin bump on his right knee 3 months ago, which progressively increased in size and number.  He has no prior health issues and takes no medications.  The patient is outdoors frequently for work and recreational activities.  He is sexually active.  Physical examination findings are shown in the exhibit.  
Which of the following microbial organisms is most likely responsible for this patient's current condition?

Quizplus · Accepted Answer

11ec160b_37f0_c5cc_9249_21cd8e0e2233_MD0001_00 This patient has cutaneous warts (verruca vulgaris), presenting as painless, skin-colored papules with a dry, whitish surface. Warts may be single or multiple and can also form irregular plaques or complex filiform structures. The diagnosis of cutaneous warts is usually made on inspection, although a magnified view (ie, dermatoscopy) can be helpful and typically reveals small black dots representing thrombosed capillaries. Cutaneous warts are caused by human papillomavirus (HPV), which is also the cause of plantar warts and anogenital warts (ie, condyloma acuminata). Infection is most prevalent in children, adolescents, and young adults and is usually acquired through direct contact. Immunosuppressed patients (eg, HIV infection) are at increased risk and often develop numerous, large lesions. Although the HPV family is associated with an increased risk for mucosal squamous cell carcinoma (eg, cervical cancer), this is primarily related to high-risk HPV types (eg, 16, 18); most cutaneous warts are due to low-risk types (eg, 2, 4), and malignant transformation is rare. (Choice A) Coxsackievirus is the most common etiologic agent in hand-foot-and-mouth disease, which is characterized by low-grade fever and vesicles/ulcers on the oral mucosa and skin (especially hands and feet). Chronic papules are more consistent with cutaneous warts. (Choice B) Herpes simplex virus causes herpetic whitlow, which presents acutely with a prodrome of burning/tingling followed by single or multiple vesicles on an erythematous base. (Choice D) Disseminated gonococcal infection causes a pustular or bullous rash, which commonly involves both the extremities and torso. It is typically associated with tenosynovitis and migratory polyarthralgia. (Choice E) Molluscum contagiosum is caused by a pox virus. Although it commonly presents as small papules, the lesions are smooth, pearly, and umbilicated, unlike the rough, dry lesions in this patient. (Choice F) Condyloma lata is a manifestation of secondary syphilis, caused by Treponema pallidum. Although it may present as verruciform lesions, it is often associated with fever and lymphadenopathy and is most common on the oral mucosa or genital area near the site of primary infection. Educational objective: Cutaneous warts are caused by human papillomavirus (HPV) and typically present as skin-colored papules with a dry, whitish surface. HPV is usually transmitted by direct contact. __________ References: Cutaneous human papillomavirus infection: manifestations and diagnosis. (http://www.ncbi.nlm.nih.gov/pubmed/24643180)

A 22-Year-Old Man Comes to the Office Due to Skin