A 19-year-old woman comes to the physician with a 1-week history of malaise and joint pains. She also has mild shortness of breath. The patient initially developed left elbow pain and swelling but now has pain in the right knee and ankle. She emigrated from Thailand 6 months ago and has resided with family members in New York City, none of whom have been ill.
Her temperature is 38 C (100.4 F), blood pressure is 104/64 mm Hg, pulse is 92/min, and respirations are 20/min. Lungs are clear bilaterally. Cardiac examination reveals a blowing 3/6 holosystolic murmur at the apex. The right knee and left elbow are mildly swollen and tender. There are palpable subcutaneous nodules on the extensor surface of both arms.
Erythrocyte sedimentation rate is 100 mm/hr and blood cultures are negative.
Which of the following is most useful in confirming the diagnosis?

Question

A 19-year-old woman comes to the physician with a 1-week history of malaise and joint pains.  She also has mild shortness of breath.  The patient initially developed left elbow pain and swelling but now has pain in the right knee and ankle.  She emigrated from Thailand 6 months ago and has resided with family members in New York City, none of whom have been ill.
Her temperature is 38 C (100.4 F), blood pressure is 104/64 mm Hg, pulse is 92/min, and respirations are 20/min.  Lungs are clear bilaterally.  Cardiac examination reveals a blowing 3/6 holosystolic murmur at the apex.  The right knee and left elbow are mildly swollen and tender.  There are palpable subcutaneous nodules on the extensor surface of both arms.
Erythrocyte sedimentation rate is 100 mm/hr and blood cultures are negative.
Which of the following is most useful in confirming the diagnosis?

Quizplus · Accepted Answer

11ec193a_9868_b8d5_853d_4de7119a1a60_MD0002_00 This patient's history (recent emigration) and presentation with fever, arthralgias, migratory arthritis, subcutaneous nodules, mitral regurgitation murmur, and elevated erythrocyte sedimentation rate (ESR) are suggestive of acute rheumatic fever (ARF). Rheumatic fever occurs 2-4 weeks after pharyngeal infection with group A β-hemolytic Streptococcus (GAS). ARF is a clinical diagnosis that is typically made using the Jones criteria (Table). Evaluation includes assessment of cardiac function and acute phase reactants (ESR and C-reactive protein) along with one of the following studies to establish GAS infection: Positive throat culture for GAS (negative in 75% of patients with ARF)Positive rapid streptococcal antigen testElevated or rising antistreptolysin O (ASO) antibody titer Positive throat culture for GAS (negative in 75% of patients with ARF) Positive rapid streptococcal antigen test Elevated or rising antistreptolysin O (ASO) antibody titer Diagnosis of ARF is based on evidence of GAS infection and 2 major (or 1 major and 2 minor) manifestations of the Jones criteria. Patients must be treated with a full course of antibiotics to eradicate GAS carriage regardless of the presence of pharyngitis at the time of diagnosis. They are also at high risk for recurrence and progression of rheumatic heart disease with repeated episodes of GAS pharyngitis. Therefore, these patients must be treated with continuous antibiotic prophylaxis to prevent recurrent pharyngitis and limit progression of rheumatic heart disease. (Choice A) Antineutrophil cytoplasmic antibodies (ANCA) are associated with granulomatosis with polyangiitis (GPA, also known as Wegener's granulomatosis), microscopic polyangiitis (MPA), Churg-Strauss syndrome, and renal-limited vasculitis. Patients with GPA or MPA are typically older and have constitutional symptoms, leukocytoclastic angiitis, and pulmonary-renal complications. Cardiac valves are not typically involved. (Choices B and D) Antinuclear antibodies (ANA) and rheumatoid factor are used to screen for systemic lupus erythematosus, rheumatoid arthritis, and other rheumatologic autoimmune diseases. Patients may have constitutional and musculoskeletal symptoms as in this patient, but cardiac valves are not typically involved. (Choice E) Knee aspiration for synovial fluid analysis is indicated in patients with suspected septic arthritis or crystal induced synovitis. These conditions usually cause a severe monoarthritis, rather than the migratory polyarthritis seen in this patient. Educational objective: Acute rheumatic fever is characterized by fever, migratory arthritis, subcutaneous nodules, carditis/valvular heart disease, and elevated inflammatory markers (erythrocyte sedimentation rate, C-reactive protein). It is diagnosed clinically based on the Jones criteria in conjunction with confirmation of group A Streptococcal infection. __________ References: Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis. (http://www.ncbi.nlm.nih.gov/pubmed/19246689) Guidelines for the diagnosis of rheumatic fever. (http://www.ncbi.nlm.nih.gov/pubmed/1404745) Diagnostic criteria of acute rheumatic fever. (http://www.ncbi.nlm.nih.gov/pubmed/24424191)

A 19-Year-Old Woman Comes to the Physician with a 1-Week