Acute Rheumatic Fever Flashcards
What is rheumatic fever (RF)?
A noninfectious consequence of pharyngitis caused by group A β-hemolytic streptococci (GABHS).
What are the common presentations of acute rheumatic fever?
- Arthritis
- Carditis
- Chorea
- Erythema marginatum
- Subcutaneous nodules
What is the major long-term consequence of acute rheumatic fever?
Valvular heart disease.
What is the estimated annual occurrence of acute rheumatic fever in the developing world?
Between 1 and 194 per 100,000 population.
Which populations have the highest rates of acute rheumatic fever?
- Indigenous people in the Northern Territory of Australia
- Countries in the South Pacific
What is the estimated global prevalence of rheumatic heart disease (RHD) as of 2015?
Over 34 million people, with over 29 million in developing countries.
What factors contributed to the decline of acute rheumatic fever in the United States since the 1960s?
- Improved socioeconomic status
- Less crowded housing conditions
- Advent of antibiotics
- Widespread treatment of streptococcal throat infections
What is a significant factor in the pathogenesis of acute rheumatic fever?
An autoimmune process.
What are the salient features of the pathogenesis of acute rheumatic fever?
- Human host with RF susceptibility factors
- Pharyngitis
- Immune response against specific streptococcal antigens
- Interval of 1–5 weeks between pharyngitis and ARF development
Which racial groups have an increased susceptibility to rheumatic fever?
- Samoans in Hawaii
- Maori in New Zealand
What are the serotypes of GABHS commonly associated with initiating ARF?
- M-types 1, 3, 5, 6, 14, 18, 19, 24, 27, and 29
True or False: Skin infections with GABHS can lead to acute rheumatic fever.
False.
What is the primary mechanism of damage in acute rheumatic fever?
Autoimmune injury due to cross-reactive antibodies.
What are Aschoff bodies?
Granulomatous reactions formed in response to the damage of collagenous matrix in ARF.
What is the characteristic pathological finding in the myocardium associated with ARF?
Fibrinoid necrosis and granulomatous inflammation.
What type of pericarditis is typically associated with acute rheumatic fever?
Fibrinous pericarditis.
Fill in the blank: Acute rheumatic fever is a febrile multisystem disorder known as _______.
ARF.
What are the typical valve lesions associated with rheumatic heart disease?
Inflammation and thickening of the valves.
What is the role of T cells in the pathogenesis of ARF?
T cells become activated by streptococcal antigens and contribute to tissue damage.
What is the typical histopathologic damage to the myocardium in ARF?
Little histopathologic damage; myocyte necrosis is uncommon.
What is the common clinical manifestation of migratory polyarthritis in ARF?
Swelling with serous effusion in the joints.
What is the primary focus of ARF-induced damage?
Endothelium and subendothelial and perivascular connective tissue.
What is the significance of the M-protein in the pathogenesis of ARF?
It can trigger cross-reactive antibodies and T-cell responses.
What are verrucae in the context of rheumatic heart disease?
Minute, translucent nodular vegetations located along the lines of closure on the inflow (atrial) side of the leaflets
They represent foci of fibrinoid necrosis and thrombosis devoid of micro-organisms.
What is Libman-Sacks endocarditis (LSE)?
A type of sterile vegetative endocarditis caused by systemic lupus erythematosus (SLE), characterized by small or medium-sized vegetations on either or both sides of the valve leaflets.
How does rheumatic vegetative endocarditis differ from non-bacterial thrombotic endocarditis (NBTE) and infective endocarditis (IE)?
Both types of rheumatic vegetative endocarditis are distinct in their patterns compared to NBTE and IE.
What occurs to the valve tissue during the repair process after rheumatic fever?
Involves ingrowth of blood vessels (neovascularization) and deposition of collagen.
What is the earliest manifestation of acute rheumatic fever (ARF)?
Arthritis.
Which joints are commonly involved in arthritis associated with rheumatic fever?
Larger joints of the extremities, with occasional involvement of smaller joints in the hands and feet.
What are Aschoff bodies?
Granulomatous lesions that result from autoimmune injury in rheumatic fever.
What are the long-term effects of acute rheumatic fever on the heart?
Can lead to chronic rheumatic heart disease, characterized by stenosis and regurgitation of the mitral and/or aortic valves.
What characterizes Sydenham chorea?
A late manifestation of ARF with involuntary movements involving the face and extremities, often associated with emotional lability.
What is the role of echocardiography in diagnosing rheumatic carditis?
It can document valvular regurgitation and detect subclinical carditis.
What are the major criteria for diagnosing acute rheumatic fever according to Jones criteria?
- Carditis
- Chorea
- Subcutaneous nodules
- Migratory arthritis involving large joints
- Erythema marginatum.
What are the minor criteria for diagnosing acute rheumatic fever?
- Arthralgia
- Fever
- Prolonged PR interval
- Elevated inflammatory markers.
True or False: Carditis is the only manifestation of rheumatic fever that leads to permanent deformity.
True.
What is a characteristic feature of the inflammation seen in rheumatic heart disease?
The presence of neovascularization and thick-walled blood vessels in the valve leaflets.
What is the typical duration for arthritis in rheumatic fever?
Usually resolves in 3-4 weeks, even without treatment.
What is the significance of an elevated antistreptolysin O (ASO) titer in diagnosing rheumatic fever?
It indicates previous streptococcal infection and is a prerequisite for diagnosis.
What is the recommended change in the Jones criteria regarding subclinical carditis?
It should be considered a major criterion.
What is a common histological finding in myocarditis associated with rheumatic fever?
Minimal myocyte damage.
What is the typical presentation of rheumatic pericarditis?
Evanescent pericardial friction rub, often associated with severe carditis.
What can mask the underlying valvular murmurs in rheumatic pericarditis?
A pericardial rub.
What is the clinical significance of post-streptococcal arthropathy?
Characterized by recurrent, severe, prolonged polyarthritis that is not very responsive to nonsteroidal anti-inflammatory agents.
What types of valve diseases are most commonly seen in rheumatic fever?
- Mitral valve disease (70% of cases)
- Aortic valve disease (5-8% of cases).
Fill in the blank: The inflammatory changes in the aortic valves can result in _______.
aortic regurgitation.
What is the relationship between chronic rheumatic heart disease and systemic lupus erythematosus?
They share similar pathologic features.
What is the migratory character of joint pain in rheumatic fever?
Joints are inflamed at different times and for various intervals.
What is the typical appearance of erythema marginatum?
Serpiginous, macular, non-pruritic, and evanescent rash on the trunk and proximal extremities.
What viral syndromes are associated with carditis?
Coxsackie B virus, Lyme disease, Kawasaki infection
These conditions can lead to inflammatory abnormalities of the heart valves.
Which collagen diseases may confuse the diagnosis of carditis?
Systemic lupus erythematosus, rheumatoid arthritis
These diseases can present early manifestations that mimic carditis.
What is the prerequisite for the diagnosis of rheumatic fever (RF)?
Evidence of previous streptococcal infection
RF is a postinfectious immunologic complication.
What are the commonly used antibody tests for streptococcal infection?
- ASO (Antistreptolysin O)
- Anti-DNase B
- Hyaluronidase
- Streptokinase
- Nicotinamide adenine dinucleotide (NAD)
These tests help assess recent streptococcal infections.
What ASO level is generally used for diagnosis in adults?
More than 240 U
For children, the threshold is more than 330 U.
What can ST-segment changes in an electrocardiogram indicate in patients with RF?
Pericarditis
Repolarization abnormalities may indicate myocarditis.
What is the role of echocardiography in diagnosing RF?
Diagnosing and monitoring cardiac structure and function
It helps identify valve regurgitation and assess cardiac damage.
In developing countries, what is a major challenge in diagnosing RF?
Limited access to medical care
Patients often present with recurrences and established heart disease.
What is the significance of echocardiography in patients with advanced RF disease?
Its incremental diagnostic benefit is questionable
Many echodetectable cases are also clinically detected within a short follow-up.
What is the primary objective in treating acute RF?
Eliminating the offending streptococci with antibiotic therapy
Penicillin is the agent of choice.
What is a common adverse prognostic indicator in RF patients?
Congestive heart failure (CHF)
CHF that does not improve with treatment is associated with the worst prognosis.
What valvular lesion may develop late after an acute RF infection?
Mitral stenosis
Symptoms often appear only after 20 years, with complications like atrial fibrillation.
Fill in the blank: The antibody response to various streptococcal antigens develops within the first month and remains detectable for _______.
3–6 months
True or False: Echocardiography is universally beneficial for diagnosing RF in developed countries.
False
Its routine use has not improved prophylaxis adherence.
What is the consequence of valve dysfunction in RF patients?
Risk for subacute bacterial endocarditis
Prophylactic antibiotics are recommended before procedures.
