July 29, 2012

Q&A: Concerning Features of Rheumatic Fever

Acute rheumatic fever (ARF) is a nonsuppurative sequela that occurs two to four weeks following group A Streptococcus (GAS) pharyngitis and may consist of arthritis, carditis, chorea, erythema marginatum, and subcutaneous nodules. Damage to cardiac valves may be chronic and progressive, resulting in cardiac decompensation.

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This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Allergies and Allergic Reaction article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.
In this article:
Complications of Streptococcal infection
MCQ: clinical scenario
MCQ: answer
MCQ: explanation

Complications of Streptococcal infection

The potential complications of group A Streptococcus (GAS) pharyngeal infection include both suppurative (eg, peritonsillar abscess, otitis media, sinusitis) and inflammatory, nonsuppurative conditions. Acute rheumatic fever (ARF) is one of the nonsuppurative complications (others include scarlet fever and acute glomerulonephritis [AGN]). There is a latent period of two to three weeks following the initial pharyngitis before the first signs or symptoms of ARF appear. The disease presents with various manifestations that may include arthritis or arthralgia, carditis, chorea, subcutaneous nodules, and erythema marginatum.

MCQ: clinical scenario

A young girl is suspected of having an acute attack of Rheumatic fever. During the acute phase of Rheumatic fever the characteristic inflammatory lesions found in the heart are known as:

a) Ferruginous bodies
b) Foamy macrophages
c) Aschoff bodies
d) Granuloma
e) Streptococcal laden macrophages

MCQ questions & answers on medicalnotes.info

MCQ: answer

The correct answer is C.

MCQ: explanation

Aschoff bodies is the name given to the characteristic inflammatory lesions found in the heart in acute Rheumatic fever. They constitute foci of fibrinoid necrosis surrounded by lymphocytes, macrophages, occasional plasma cells and plump activated histiocytes called the aschoff cells. These lesions are sterile and do not contain any bacteria. Aschoff body is pathognomonic of acute Rheumatic fever.

Ferruginous bodies are iron coated asbestos particles seen in pulmonary asbestosis. They are not seen in rheumatic fever. Foamy macrophages are lipid laden macrophages seen in an atherosclerotic plaque and are not seen in rheumatic fever. Granuloma is focus of inflammation characterized by activated macrophages called epitheloid cells. They are seen in a variety of infectious and non-infectious conditions but are not seen in rheumatic fever. Option E is not the correct answer because even though Rheumatic fever takes place following a streptococcal infection it is more of an autoimmune reaction to the streptococcal antigen and the lesions are sterile not containing any bacteria.

Reference(s)
1). UpToDate: Acute rheumatic fever: Epidemiology and pathogenesis. Available online: https://www.uptodate.com/contents/acute-rheumatic-fever-epidemiology-and-pathogenesis
2). UpToDate: Acute rheumatic fever: Clinical manifestations and diagnosis. Available online: https://www.uptodate.com/contents/acute-rheumatic-fever-clinical-manifestations-and-diagnosis

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