A 37-year-old woman comes to the clinic for evaluation of a rash. She has a few small, red rashes on her shoulders and lower back, which have gradually increased in size over the last 2 weeks. The rashes are slightly itchy but not painful. Vital signs are normal. Skin examination findings are shown in the exhibit. The remainder of the examination is normal. Which of the following is the most appropriate treatment for this patient?

Question

A 37-year-old woman comes to the clinic for evaluation of a rash.  She has a few small, red rashes on her shoulders and lower back, which have gradually increased in size over the last 2 weeks.  The rashes are slightly itchy but not painful.  Vital signs are normal.  Skin examination findings are shown in the exhibit.  The remainder of the examination is normal.  Which of the following is the most appropriate treatment for this patient?

Quizplus · Accepted Answer

11ec25c8_d281_7941_bc81_5113239b848e_MD0003_00 This patient has several flat, annular lesions with central clearing, raising strong suspicion for early disseminated Lyme disease. Lyme disease is caused by the spirochete Borrelia burgdorferi and is transmitted by the Ixodes scapularis deer tick in endemic areas. B burgdorferi replicates in the dermis at the site of inoculation and usually causes the hallmark rash of erythema migrans (EM) 7-14 days after transmission. EM begins as a confluent macule that slowly expands outwards and develops into an annular lesion with central clearing ("bull's-eye" rash). Most cases are minimally pruritic and not painful. endemic areas Although early localized Lyme disease is marked by the formation of a single EM lesion at the site of inoculation, hematologic spread can lead to the formation of multiple EM lesions, a sign of early disseminated Lyme disease. Early disseminated disease usually occurs weeks or months after inoculation, and patients frequently do not remember a previous tick bite or rash. Concomitant manifestations in the CNS (eg, radiculopathy, lymphocytic meningitis, cranial nerve palsy) or heart (eg, atrioventricular block) can also occur. Because patients with early disseminated and late Lyme disease have a fully formed humoral antibody response, the diagnosis is made with Lyme serology. Treatment with a prolonged course of oral doxycycline is usually curative, but patients with more serious complications (eg, carditis, meningitis) require intravenous ceftriaxone. (Choices B and F) Topical ketoconazole and terbinafine are often used to treat tinea corporis. Tinea corporis can cause several large, annular lesions with central clearing. However, the lesions are usually scaly with raised borders and are intensely pruritic. tinea corporis (Choice C) Prednisone is occasionally used to treat severe drug reactions, which can cause annular macular lesions. However, the lesions tend to be pruritic and do not have central clearing. (Choice D) Reassurance and observation are appropriate for viral exanthem, which most commonly presents with a diffuse, maculopapular rash in the context of fever, pharyngitis, and/or upper respiratory symptoms. Slow-spreading, annular lesions with central clearing would be atypical. viral exanthem (Choice E) Selenium sulfide is often used to treat tinea versicolor, a lipid-dependent yeast infection of the skin. Although patients typically develop large, macular lesions on the trunk or upper extremities, the rash is scaly and does not typically have central clearing. tinea versicolor Educational objective: Multiple erythema migrans are pathognomonic for early disseminated Lyme disease, even without a known history of a tick bite. Systemic symptoms (eg, malaise, headache, fever) may be present. Doxycycline is the treatment of choice. References: Diagnosis, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: a review. (http://www.ncbi.nlm.nih.gov/pubmed/27115378)

A 37-Year-Old Woman Comes to the Clinic for Evaluation of a Rash