A 19-year-old college student comes to the office due to painful lesions on his right hand for the past several days. He has also felt feverish and tired. The patient has a history of folliculitis and skin abscess requiring surgical drainage. Over the past 6 months, he has had 3 sexual partners and uses condoms inconsistently. He began a part-time landscaping job a month ago. Temperature is 37.4 C (99.3 F), blood pressure is 130/84 mm Hg, and pulse is 86/min. Right hand examination findings are shown below. He has no other skin rash and the remainder of the physical examination is normal. Which of the following is the most likely causative organism of this patient's condition?

Question

A 19-year-old college student comes to the office due to painful lesions on his right hand for the past several days.  He has also felt feverish and tired.  The patient has a history of folliculitis and skin abscess requiring surgical drainage.  Over the past 6 months, he has had 3 sexual partners and uses condoms inconsistently.  He began a part-time landscaping job a month ago.  Temperature is 37.4 C (99.3 F), blood pressure is 130/84 mm Hg, and pulse is 86/min.  Right hand examination findings are shown below.  He has no other skin rash and the remainder of the physical examination is normal.  Which of the following is the most likely causative organism of this patient's condition?

Quizplus · Accepted Answer

This young patient with multiple sexual partners has mild systemic symptoms and a painful, vesicular hand rash suggesting herpetic whitlow. Herpetic whitlow arises when herpes simplex virus (HSV) inoculates a cutaneous defect of the hand. In adults, infections typically occur after hand contact with an active genital herpes lesion (HSV-2). Risk is also increased in health care workers who do not use adequate hand protection and are exposed to infected orotracheal secretions (HSV-1). Symptoms usually include a mild prodrome (fever, malaise), followed by the development of a focal area of grouped vesicles on an erythematous base. Tingling, burning, and pain are common, and some patients may have epitrochlear or axillary lymphadenopathy. Most lesions resolve spontaneously within 2-3 weeks, but patients with immunocompromise may require antiviral medication (eg, acyclovir). Recurrent lesions occur in 20%-50% of cases. (Choices A and G) β-hemolytic streptococci and Staphylococcus aureus are common causes of erysipelas and cellulitis. Manifestations typically include skin erythema, edema, and warmth; vesicular lesions would be unusual. (Choice B) Coxsackievirus causes hand-foot-and-mouth disease and usually manifests with oral lesions and a bilateral macular, maculopapular, or vesicular rash of the hands and feet. This patient with a localized, unilateral rash on a small section of the hand is unlikely to have coxsackievirus. rash (Choice D) Disseminated gonococcus may cause tenosynovitis, polyarthralgia, and cutaneous lesions on the distal extremities that begin as macules and progress to papules, pustules, vesicles, or bullae. Lesions are usually painless (not painful) and multiple (not single). (Choice E) Pseudomonas aeruginosa may cause folliculitis after hot tub exposure or cellulitis after a nail puncture through a shoe. Neither is likely to result in a small area of vesicular eruption. (Choice F) Rocky Mountain spotted fever (RMSF) is a tick-borne rickettsial illness that usually manifests with nonspecific signs (fever, headache, malaise, myalgias) and a diffuse macular rash that turns petechial. This patient with a focal vesicular rash is unlikely to have RMSF. (Choice H) Secondary syphilis causes a diffuse, symmetric macular/papular rash that includes the palms and soles. A focal, unilateral, vesicular lesion is unlikely. (Choice I) Trichophyton rubrum is a dermatophyte that causes ringworm, tinea pedis, and tinea manuum. Rashes are typically pruritic and scaly (not vesicular). Educational objective: Herpetic whitlow is a viral infection of the hand caused by herpes simplex virus. Most adult infections are acquired from contact with genital herpetic lesions or infected orotracheal secretions. Spontaneous resolution is the norm but recurrences are common.

A 19-Year-Old College Student Comes to the Office Due to Painful