A 25-year-old man comes to the office due to a painless ulcer on his penis. He has no fever or urethral discharge. A few weeks ago, he had unprotected vaginal sex with a sex worker. The patient previously required hospitalization in the intensive care unit for toxic epidermal necrolysis after taking penicillin. He has no other medical conditions and takes no medications. Vital signs are within normal limits. Physical examination shows a shallow, nontender, and nonexudative penile ulcer with a smooth base. Mild, bilateral inguinal lymphadenopathy is present. Serum rapid plasma reagin is positive, and HIV testing is negative. Which of the following is the most appropriate treatment for this patient?

Question

A 25-year-old man comes to the office due to a painless ulcer on his penis.  He has no fever or urethral discharge.  A few weeks ago, he had unprotected vaginal sex with a sex worker.  The patient previously required hospitalization in the intensive care unit for toxic epidermal necrolysis after taking penicillin.  He has no other medical conditions and takes no medications.  Vital signs are within normal limits.  Physical examination shows a shallow, nontender, and nonexudative penile ulcer with a smooth base.  Mild, bilateral inguinal lymphadenopathy is present.  Serum rapid plasma reagin is positive, and HIV testing is negative.  Which of the following is the most appropriate treatment for this patient?

Quizplus · Accepted Answer

11ec25c8_d46e_5540_bc81_b9c63b1a06a2_MD0003_00 This patient had intercourse with a sex worker and subsequently developed a penile chancre (painless, nonexudative ulcer), inguinal lymphadenopathy, and a positive rapid plasma reagin (RPR) test, indicating primary syphilis. First-line treatment for primary syphilis is a single dose of intramuscular benzathine penicillin G, which provides therapeutic levels of penicillin for approximately 3 weeks. However, patients who are unable to take penicillin due to severe penicillin allergy can be treated with an alternate regimen such as 14 days of oral doxycycline or 10-14 days of intravenous or intramuscular ceftriaxone. Alternate regimens are generally recommended for patients with severe penicillin allergy who have any stage of syphilis other than neurosyphilis; patients with neurosyphilis who have severe penicillin allergy usually require penicillin desensitization followed by administration of penicillin to ensure eradication of the organism (penicillin has 100% efficacy against the organism and excellent central nervous system penetration). All patients with syphilis require nontreponemal titers (eg, RPR) at the time of treatment and again at 6-12 months to ensure adequate response (a 4-fold drop in titers). This is especially important for patients receiving alternate regimens because the risk of treatment failure is greater than in those who receive penicillin. (Choice A) Doxycycline is generally considered the best alternate treatment of primary syphilis due to ease of administration and efficacy. Although amoxicillin plus probenecid can also be used for primary syphilis, this patient with severe penicillin allergy should not be given amoxicillin. (Choice B) Ciprofloxacin is effective against most gram-negative enteric organisms but has no efficacy against syphilis. (Choice C) Clindamycin is often used to treat airway and skin aerobic and anaerobic infections, but it has no efficacy against syphilis. (Choice E) Trimethoprim-sulfamethoxazole has fairly broad efficacy against gram-negative, gram-positive, and atypical organisms but does not effectively treat syphilis. Educational objective: A single dose of intramuscular benzathine penicillin G is the treatment of choice for early syphilis. However, patients with severe penicillin allergy (who do not have neurosyphilis) generally require an alternate regimen such as oral doxycycline or IV/IM ceftriaxone. All patients with syphilis should have pretreatment serology with a nontreponemal test (eg, rapid plasma reagin) to quantitate antibody titers. A 4-fold decrease in antibody titers at 6-12 months indicates treatment success. References: Sexually transmitted diseases treatment guidelines, 2015. (http://www.ncbi.nlm.nih.gov/pubmed/26042815) Syphilis: a reemerging infection. (http://www.ncbi.nlm.nih.gov/pubmed/22963062)

A 25-Year-Old Man Comes to the Office Due to a Painless