A 22-year-old woman, gravida 1 para 0, at 12 weeks gestation comes to the office due to 3 days of rash, fever, and malaise. The rash seems to be getting larger but does not hurt or itch. Two weeks ago, the patient went camping in northern Massachusetts and had a tick bite while walking through the woods. She has no known drug allergies. Temperature is 38.3 C (101 F), blood pressure is 110/80 mm Hg, pulse is 88/min, and respirations are 16/min. The rash is shown in the image below. The remainder of the examination is normal. Which of the following is the most appropriate next step in the management of this patient?

Question

A 22-year-old woman, gravida 1 para 0, at 12 weeks gestation comes to the office due to 3 days  of rash, fever, and malaise.  The rash seems to be getting larger but does not hurt or itch.  Two weeks ago, the patient went camping in northern Massachusetts and had a tick bite while walking through the woods.  She has no known drug allergies.  Temperature is 38.3 C (101 F), blood pressure is 110/80 mm Hg, pulse is 88/min, and respirations are 16/min.  The rash is shown in the image below.  The remainder of the examination is normal.  Which of the following is the most appropriate next step in the management of this patient?

Quizplus · Accepted Answer

This patient camped in a Lyme-endemic area and subsequently developed systemic symptoms and a macular lesion, raising strong suspicion for early localized Lyme disease. Lyme disease is a spirochetal infection (Borrelia burgdorferi) transmitted by the deer tick Ixodes scapularis. Most patients develop manifestations of early localized Lyme disease 7-14 days after transmission. Spirochetal replication in the dermis generates the rash of erythema migrans-a slowly expanding, macular lesion that eventually forms areas of central clearing ("bull's-eye" rash). Systemic symptoms (eg, fever, headache, myalgia, fatigue) also commonly occur. Lyme-endemic area First-line treatment for early localized Lyme disease in nonpregnant adults is doxycycline due to excellent systemic penetration and efficacy against other pathogens (eg, Anaplasma phagocytophilum) commonly transmitted by Ixodes scapularis. In pregnant women, the use of doxycycline is more controversial (eg, possible risk of fetal tooth discoloration and retardation of skeletal development) and is generally only considered on a case-by-case basis (eg, short therapy duration, gestational age). In this patient population, oral amoxicillin is often used in lieu of doxycycline for treatment of Lyme disease. Azithromycin is less effective than amoxicillin and doxycycline for Lyme disease and is generally reserved for patients with allergies to both of these medications (Choice B). Lyme disease during pregnancy does not appear to cause harm to the fetus. (Choice C) Ceftriaxone is reserved for severe complications of later stages of Lyme disease (eg, meningitis, carditis). It is not used in early disseminated Lyme disease because oral agents are highly effective and more easily administered. (Choice D) Ciprofloxacin is primarily used to treat gram-negative enteric pathogens. It is not effective against Lyme disease. (Choice E) Observation would lead to spirochetal dissemination and high risk for later complications (eg, facial nerve palsy, aseptic meningitis, heart block, arthritis). Educational objective: Pregnant patients with early localized Lyme disease are typically treated with amoxicillin. This treatment is generally curative and does not pose a risk to the fetus.

A 22-Year-Old Woman, Gravida 1 Para 0, at 12 Weeks