A 23-year-old woman comes to the emergency department due to 2 hours of fever, chills, headache, and myalgias. Earlier in the day, the patient saw her primary care physician for a genital ulcer. She underwent testing for sexually transmitted infections and was found to have a positive VDRL and fluorescent treponemal antibody absorption test. The remainder of her testing was negative. The patient received an intramuscular injection of benzathine penicillin G, and several hours later her current symptoms began. Temperature is 38 C (100.4 F), blood pressure is 120/70 mm Hg, and pulse is 92/min and regular. Lung sounds are normal. There is an indurated, nontender vulval ulcer and several enlarged inguinal lymph nodes. No other skin rash is present. Which of the following is the most likely cause of this patient's current symptoms?

Question

A 23-year-old woman comes to the emergency department due to 2 hours of fever, chills, headache, and myalgias.  Earlier in the day, the patient saw her primary care physician for a genital ulcer.  She underwent testing for sexually transmitted infections and was found to have a positive VDRL and fluorescent treponemal antibody absorption test.  The remainder of her testing was negative.  The patient received an intramuscular injection of benzathine penicillin G, and several hours later her current symptoms began.  Temperature is 38 C (100.4 F), blood pressure is 120/70 mm Hg, and pulse is 92/min and regular.  Lung sounds are normal.  There is an indurated, nontender vulval ulcer and several enlarged inguinal lymph nodes.  No other skin rash is present.  Which of the following is the most likely cause of this patient's current symptoms?

Quizplus · Accepted Answer

11ec160b_3bfc_fea2_9249_a796b6b8f69b_MD0001_00 This patient with a genital ulcer, inguinal lymphadenopathy, and positive nontreponemal/treponemal testing was treated for primary syphilis with intramuscular benzathine penicillin G. She then developed an acute febrile syndrome (fever, chills, myalgia, headache) a few hours later, raising strong suspicion for the Jarisch-Herxheimer reaction. This systemic inflammatory response occurs within hours of antibiotic initiation for spirochetal infections (eg, syphilis, Lyme disease, leptospirosis). The rapid lysis of spirochetes spills bacterial lipoproteins into the bloodstream and triggers a strong innate immunologic response. Most cases are self-limited and do not require intervention. (Choice A) Conjugation of antibiotic and host antigens can cause drug-induced fever, which typically arises several days or a few weeks (not within hours) after drug initiation. Patients often have fever and rash. (Choice B) Syphilis is universally susceptible to penicillin. In addition, secondary syphilis (eg, widespread maculopapular rash, constitutional symptoms, lymphadenopathy) develops weeks or months after the chancre of primary syphilis; therefore, disease progression is unlikely in this case. (Choice D) Penicillin allergy is due to immune sensitization following previous exposure. Additional exposure triggers an IgE-mediated (type I) allergic response; symptoms often include rash, bronchospasm, angioedema, flushing, hypotension, and/or pruritis. Fever, chills, headache, and myalgias would be atypical and are more consistent with the Jarisch-Herxheimer reaction. (Choice E) Intramuscular benzathine penicillin G is a long-acting drug that is excreted in the urine. Poor renal tubular secretion could increase plasma drug concentrations but would be unlikely to induce a systemic inflammatory response. Educational objective: The Jarisch-Herxheimer reaction is an acute inflammatory reaction that occurs within hours of treatment for spirochetal infections (eg, syphilis). The rapid lysis of spirochetes releases inflammatory bacterial lipoproteins into the circulation and causes acute fever, rigors, and myalgias.

A 23-Year-Old Woman Comes to the Emergency Department Due to 2