A 24-year-old man comes to the urgent care clinic with a penile lesion that appeared a week ago as a painful papule and has since changed and worsened. The patient regularly uses intravenous heroin and had unprotected sex with a female acquaintance in exchange for a small amount of heroin 2 weeks ago. He has no history of sexually transmitted infections. Temperature is 36.7 C (98 F), blood pressure is 120/70 mm Hg, and pulse is 78/min. Cardiopulmonary examination is normal. The abdomen is soft and nontender. Genital examination reveals a tender, 1.5-cm ulcer on the prepuce with well-demarcated, undermined borders and a purulent exudate. Two smaller ulcers with a similar appearance are near the larger ulcer. He has no penile discharge and the scrotum appears normal. Several inguinal lymph nodes are enlarged and tender. Skin examination shows track marks in the antecubital area but no other rash. Which of the following is the most likely cause of this patient's penile ulcer?

Question

A 24-year-old man comes to the urgent care clinic with a penile lesion that appeared a week ago as a painful papule and has since changed and worsened.  The patient regularly uses intravenous heroin and had unprotected sex with a female acquaintance in exchange for a small amount of heroin 2 weeks ago.  He has no history of sexually transmitted infections.  Temperature is 36.7 C (98 F), blood pressure is 120/70 mm Hg, and pulse is 78/min.  Cardiopulmonary examination is normal.  The abdomen is soft and nontender.  Genital examination reveals a tender, 1.5-cm ulcer on the prepuce with well-demarcated, undermined borders and a purulent exudate.  Two smaller ulcers with a similar appearance are near the larger ulcer.  He has no penile discharge and the scrotum appears normal.  Several inguinal lymph nodes are enlarged and tender.  Skin examination shows track marks in the antecubital area but no other rash.  Which of the following is the most likely cause of this patient's penile ulcer?

Quizplus · Accepted Answer

11ec25c8_d441_2a6d_bc81_9f07a149ebda_MD0003_00 This patient had a high risk sexual encounter and then developed a painful genital papule that progressed to an ulcer, suggesting Haemophilus ducreyi (chancroid) infection. H ducreyi is a fastidious, gram-negative rod that is a major sexually transmitted pathogen in Sub-Saharan Africa, Southeast Asia, and Latin America. Infections are relatively rare in the United States, but outbreaks have occurred in those who trade sex for drugs or money. Several days after inoculation with H ducreyi, patients develop >1 erythematous papules that evolve into pustules and then erode into painful ulcers. The ulcers typically have an erythematous base, well-demarcated/undermined borders, and an overlying purulent exudate. Painful inguinal lymphadenitis is common. Diagnosis requires culture on specialized media; treatment with antibiotics (eg, azithromycin) is typically curative. > lymphadenitis (Choice A) Acute HIV may cause mononucleosis-like symptoms (eg, fever, fatigue, sore throat, painless lymphadenopathy), a generalized rash, and painful mucocutaneous ulceration (shallow, sharply demarcated, with a white base). This patient has no systemic symptoms, a papule that converted into an ulcer with a purulent (not white) exudate, and painful lymphadenitis. (Choice C) Neisseria gonorrhoeae is a far more common sexually transmitted infection than H ducreyi, but gonococcal infections typically cause cervicitis or urethritis (not genital ulcers). (Choice D) Primary syphilis usually manifests as a papule that converts to an ulcer with raised, indurated margins and a nonexudative base. This patient has multiple, painful ulcers with a purulent base. (Choice E) Staphylococcal ecthyma is a deep form of impetigo that typically begins as a vesicle/pustule on an inflamed area of skin and then converts to an indurated, purulent ulcer. Lesions are most common on the buttocks, thighs, and legs. Penile lesions are uncommon, and this patient with a history of high-risk unprotected sex is more likely to have chancroid. Educational objective: Haemophilus ducreyi is a gram-negative rod that causes sexually transmitted infections (chancroid) primarily in developing countries. Cases in the United States are uncommon but outbreaks have occurred in those who trade sex for drugs or money. Manifestations include the development of >1 painful papules that convert to pustules and then to ulcers (painful, erythematous base, well-demarcated borders, purulent exudate). Inguinal lymphadenitis is common. >

A 24-Year-Old Man Comes to the Urgent Care Clinic with a Penile