A 26-year-old man comes to the office due to 2 days of headache, malaise, and myalgia. The patient also has an enlarging, nonpruritic rash on his lower abdomen. He is a graduate student with no significant medical history. The patient is sexually active and uses condoms consistently. He recently returned from a 2-week camping and hiking trip in eastern Pennsylvania. The patient does not use tobacco or illicit drugs but drinks alcohol occasionally. Temperature is 38 C (100.4 F), blood pressure is 126/84 mm Hg, and pulse is 72/min. Mucous membranes are moist with no lesions. No lymphadenopathy is present. The lungs are clear to auscultation, and heart sounds are normal with no murmur. The abdomen is soft, nondistended, and nontender with no hepatosplenomegaly. There is no nuchal rigidity. Skin examination shows a 4-cm, oval, uniformly red, macular rash at the belt line. Which of the following is the best next step in management of this patient?

Question

A 26-year-old man comes to the office due to 2 days of headache, malaise, and myalgia.  The patient also has an enlarging, nonpruritic rash on his lower abdomen.  He is a graduate student with no significant medical history.  The patient is sexually active and uses condoms consistently.  He recently returned from a 2-week camping and hiking trip in eastern Pennsylvania.  The patient does not use tobacco or illicit drugs but drinks alcohol occasionally.  Temperature is 38 C (100.4 F), blood pressure is 126/84 mm Hg, and pulse is 72/min.  Mucous membranes are moist with no lesions.  No lymphadenopathy is present.  The lungs are clear to auscultation, and heart sounds are normal with no murmur.  The abdomen is soft, nondistended, and nontender with no hepatosplenomegaly.  There is no nuchal rigidity.  Skin examination shows a 4-cm, oval, uniformly red, macular rash at the belt line.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bfaa_1d01_8f63_5918e5d545aa_MD0005_00 This patient camped in a Lyme-endemic area and now has an enlarging, macular rash and viral-like symptoms, raising strong suspicion for early localized Lyme disease. Lyme disease, a spirochetal illness caused by Borrelia burgdorferi, is transmitted by the deer tick Ixodes scapularis during blood feeding. Within 1-2 weeks of transmission, most patients develop symptoms of early localized Lyme disease, including: Lyme-endemic area Erythema migrans - a slowly spreading, erythematous rash that often starts as a confluent macule and progresses over days into a bull's-eye shape (areas of central clearing) Viral-like symptoms - malaise, fatigue, arthralgias, myalgias, neck stiffness, and/or headache Serologic testing is often falsely negative in early infection due to an incompletely developed humoral antibody response. Therefore, patients with early localized Lyme disease are diagnosed clinically and treated empirically with oral doxycycline. In contrast to early localized disease, patients with early disseminated (eg, multiple erythema migrans lesions, carditis, neuritis) and late (eg, arthritis, peripheral neuropathy) Lyme disease should always undergo serologic testing prior to treatment because the humoral response against the organism is fully developed. B burgdorferi enzyme-linked immunosorbent assay followed by Western blot is used for diagnosis (Choices B and D). (Choice A) Intravenous ceftriaxone is the preferred therapy for severe manifestations of Lyme disease (eg, carditis with advanced atrioventricular block, radiculopathy, meningitis). Patients with early localized Lyme disease and/or facial nerve palsy are typically treated with oral doxycycline. (Choice C) Patients with Lyme disease may develop meningitis and require lumbar puncture for diagnosis. Although this patient has a headache, he has no nuchal rigidity, making meningitis less likely. Educational objective: Early localized Lyme disease typically occurs within 1-2 weeks of tick bite and is characterized by erythema migrans and viral-like symptoms. Diagnosis of early localized disease is made clinically because Borrelia burgdorferi serology is often falsely negative and is not recommended. Treatment with oral doxycycline is generally curative.

A 26-Year-Old Man Comes to the Office Due to 2