A 12-year-old girl comes to the office with constant swelling and pain of her elbows for the past week that have prevented her from participating in basketball practice. She also had knee pain during the preceding week that was attributed to a fall during practice. Her parents say that she is healthy and has had only minor illnesses that children typically experience during the winter. The patient's temperature is 38.9 C (102 F), blood pressure is 110/70 mm Hg, and pulse is 110/min. Her elbows are swollen and tender with limited range of movement. Her knees appear normal. A new holosystolic murmur is heard on cardiac auscultation. Antistreptolysin O titers are 400 Todd units/mL (normal:

Question

A 12-year-old girl comes to the office with constant swelling and pain of her elbows for the past week that have prevented her from participating in basketball practice.  She also had knee pain during the preceding week that was attributed to a fall during practice.  Her parents say that she is healthy and has had only minor illnesses that children typically experience during the winter.  The patient's temperature is 38.9 C (102 F), blood pressure is 110/70 mm Hg, and pulse is 110/min.  Her elbows are swollen and tender with limited range of movement.  Her knees appear normal.  A new holosystolic murmur is heard on cardiac auscultation.  Antistreptolysin O titers are 400 Todd units/mL (normal: <300 Todd units/mL).  The patient is admitted to the hospital.  During her hospitalization, this patient is at greatest risk of dying from which of the following complications?

Quizplus · Accepted Answer

11ec160b_3a67_b888_9249_97adafff67d6_MD0001_00 Acute rheumatic fever (ARF) is the most likely diagnosis in this patient with migratory arthritis, new-onset murmur, fever, and a positive anti-streptolysin O titer. ARF is a multisystem complication that develops 2-4 weeks after untreated group A streptococcal pharyngitis. Most organs are often only mildly and transiently affected in ARF, with the exception of the heart. Acute morbidity is most likely due to pancarditis (inflammation of the endocardium, myocardium, and epicardium). Inflammation of the mitral valve can lead to mitral regurgitation, which is the likely cause of the new holosystolic murmur in this patient. Severe regurgitation and/or myocarditis can lead to cardiac dilation, heart failure, and death in a small percentage of patients. (Choice A) Virtually all cases of mitral stenosis are caused by fibrosis of the valve leaflets in chronic rheumatic heart disease. The fibrosis occurs gradually over years or decades after the initial episode of ARF and would, therefore, not be an acute complication in this patient. (Choice C) Acute poststreptococcal glomerulonephritis (PSGN) is caused by circulating immune complexes following a streptococcal pharyngeal infection with specific nephritogenic strains. Hematuria, edema, proteinuria, and hypertension are classic findings. This patient has no symptoms of PSGN, which rarely occurs simultaneously with ARF. (Choice D) Patients with septic arthritis are often febrile and ill-appearing. Staphylococcus aureus is the most common cause and usually infects only one joint. (Choice E) Septic shock refers to end-organ damage due to poor perfusion from an overwhelming inflammatory response to infection. Although the pathogenesis of ARF involves an initial infection with group A streptococcus, the disease itself is autoimmune-related, not due to direct infection. Educational objective: The primary cause of morbidity in acute rheumatic fever is heart failure from severe pancarditis. Mitral stenosis develops years or decades after the original illness. Joint involvement is usually transient. __________ References: Diagnostic criteria of acute rheumatic fever. (http://www.ncbi.nlm.nih.gov/pubmed/24424191) Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Disease Society of America. (http://www.ncbi.nlm.nih.gov/pubmed/22965026)

A 12-Year-Old Girl Comes to the Office with Constant Swelling