A 37-year-old woman comes to the emergency department due to joint pain for the past 3 weeks. The pain is primarily in the lower extremities and is not associated with joint swelling or redness. She has had no skin rashes, chest pain, or urinary symptoms but has had malaise, profound fatigue, and decreased appetite. The patient's symptoms began after she visited her family in Connecticut. She has a history of mitral valve prolapse, and her current medications include oral contraceptives and a multivitamin. The patient works as a paralegal. She does not use tobacco or illicit drugs and drinks alcohol occasionally. Her mother has rheumatoid arthritis.
Temperature is 38 C (100.4 F) , blood pressure is 105/70 mm Hg, pulse is 89/min, and respirations are 18/min. BMI is 23 kg/m². The patient is mildly ill-appearing but in no acute distress. Dental hygiene is poor. Cardiopulmonary auscultation reveals clear lung fields and a 3/6 holosystolic murmur at the cardiac apex that radiates to the axillae. There is tenderness to palpation in the left upper quadrant with an enlarged spleen. No joint swelling or erythema is present, and there is no skin rash or lymphadenopathy.
Laboratory results are as follows:
Which of the following is most likely to establish the diagnosis in this patient?

Question

A 37-year-old woman comes to the emergency department due to joint pain for the past 3 weeks. The pain is primarily in the lower extremities and is not associated with joint swelling or redness. She has had no skin rashes, chest pain, or urinary symptoms but has had malaise, profound fatigue, and decreased appetite. The patient's symptoms began after she visited her family in Connecticut. She has a history of mitral valve prolapse, and her current medications include oral contraceptives and a multivitamin. The patient works as a paralegal. She does not use tobacco or illicit drugs and drinks alcohol occasionally. Her mother has rheumatoid arthritis.
Temperature is 38 C (100.4 F) , blood pressure is 105/70 mm Hg, pulse is 89/min, and respirations are 18/min. BMI is 23 kg/m². The patient is mildly ill-appearing but in no acute distress. Dental hygiene is poor. Cardiopulmonary auscultation reveals clear lung fields and a 3/6 holosystolic murmur at the cardiac apex that radiates to the axillae. There is tenderness to palpation in the left upper quadrant with an enlarged spleen. No joint swelling or erythema is present, and there is no skin rash or lymphadenopathy.
Laboratory results are as follows:

Which of the following is most likely to establish the diagnosis in this patient?

Quizplus · Accepted Answer

This patient with poor dentition and a history of mitral valve prolapse has low-grade fever, arthralgias, and likely mitral regurgitation (apex murmur radiating to axilla), raising concern for infective endocarditis (IE). Further evaluation with 3 sets of blood cultures and echocardiography is now required to estimate the likelihood of IE using the modified Duke criteria. modified Duke criteria Patients with suspected IE also usually receive a chest x-ray, ECG, and additional laboratory studies. Common laboratory abnormalities include normochromic/normocytic anemia, leukocytosis with left shift, elevated erythrocyte sedimentation rate (90% of cases), decreased complement levels (C3, C4, and CH50), and positive rheumatoid factor due to circulating immune complexes. Imaging of the spine for vertebral myelitis or abdomen for splenic infarcts (as is likely in this case) is also warranted in the appropriate clinical setting. (Choice A) Antineutrophil cytoplasmic antibodies are commonly seen in granulomatosis with polyangiitis and microscopic polyangiitis. Although both syndromes can be associated with arthralgias and systemic symptoms, most patients also have ear (eg, otitis), nose (eg, rhinorrhea, sinusitis), throat (eg, hoarseness), and/or renal manifestations (eg, glomerulonephritis). Cardiac involvement would be atypical. (Choice C) Bone marrow biopsy is most commonly performed to evaluate for hematologic malignancy. Although this patient does have splenomegaly and complete blood count abnormalities, given her dental disease, mitral valve prolapse, and constellation of manifestations, she should first undergo an evaluation for IE with blood cultures and echocardiogram. Splenomegaly can sometimes be seen with IE. If the modified Duke criteria reveals a low probability of IE, she may require bone marrow biopsy for further evaluation. (Choice D) Cervical smear and culture could diagnosis Neisseria gonorrhea infection. Disseminated gonococcus can cause a triad of symptoms (ie, tenosynovitis, pustular skin lesions, polyarthralgias) or purulent arthritis without skin lesions. This patient with polyarthritis has a cardiac murmur, splenomegaly, and no skin lesions, making IE more likely. (Choice E) Lyme disease is a tick-borne illness caused by Borrelia burgdorferi. Although this patient visited an endemic region (the northeastern United States), Lyme carditis typically presents with atrioventricular conduction block or decreased contractility due to myopericarditis. A new cardiac murmur and splenomegaly are more suggestive of IE. Educational objective: Patients with suspected infective endocarditis require blood cultures (3 sets) and echocardiography to estimate its likelihood using the modified Duke criteria. __________ References: Acute infective endocarditis. (http://www.ncbi.nlm.nih.gov/pubmed/19665088) Infectious endocarditis: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/22612050)

A 37-Year-Old Woman Comes to the Emergency Department Due to Joint