Acute Rheumatic Fever

Question 1

What is rheumatic fever (RF)?

Answer 1

A noninfectious consequence of pharyngitis caused by group A β-hemolytic streptococci (GABHS).

Question 2

What are the common presentations of acute rheumatic fever?

Answer 2

• Arthritis
• Carditis
• Chorea
• Erythema marginatum
• Subcutaneous nodules

Question 3

What is the major long-term consequence of acute rheumatic fever?

Answer 3

Valvular heart disease.

Question 4

What is the estimated annual occurrence of acute rheumatic fever in the developing world?

Answer 4

Between 1 and 194 per 100,000 population.

Question 5

Which populations have the highest rates of acute rheumatic fever?

Answer 5

• Indigenous people in the Northern Territory of Australia
• Countries in the South Pacific

Question 6

What is the estimated global prevalence of rheumatic heart disease (RHD) as of 2015?

Answer 6

Over 34 million people, with over 29 million in developing countries.

Question 7

What factors contributed to the decline of acute rheumatic fever in the United States since the 1960s?

Answer 7

• Improved socioeconomic status
• Less crowded housing conditions
• Advent of antibiotics
• Widespread treatment of streptococcal throat infections

Question 8

What is a significant factor in the pathogenesis of acute rheumatic fever?

Answer 8

An autoimmune process.

Question 9

What are the salient features of the pathogenesis of acute rheumatic fever?

Answer 9

• Human host with RF susceptibility factors
• Pharyngitis
• Immune response against specific streptococcal antigens
• Interval of 1–5 weeks between pharyngitis and ARF development

Question 10

Which racial groups have an increased susceptibility to rheumatic fever?

Answer 10

• Samoans in Hawaii
• Maori in New Zealand

Question 11

What are the serotypes of GABHS commonly associated with initiating ARF?

Answer 11

• M-types 1, 3, 5, 6, 14, 18, 19, 24, 27, and 29

Question 12

True or False: Skin infections with GABHS can lead to acute rheumatic fever.

Answer 12

False.

Question 13

What is the primary mechanism of damage in acute rheumatic fever?

Answer 13

Autoimmune injury due to cross-reactive antibodies.

Question 14

What are Aschoff bodies?

Answer 14

Granulomatous reactions formed in response to the damage of collagenous matrix in ARF.

Question 15

What is the characteristic pathological finding in the myocardium associated with ARF?

Answer 15

Fibrinoid necrosis and granulomatous inflammation.

Question 16

What type of pericarditis is typically associated with acute rheumatic fever?

Answer 16

Fibrinous pericarditis.

Question 17

Fill in the blank: Acute rheumatic fever is a febrile multisystem disorder known as _______.

Answer 17

ARF.

Question 18

What are the typical valve lesions associated with rheumatic heart disease?

Answer 18

Inflammation and thickening of the valves.

Question 19

What is the role of T cells in the pathogenesis of ARF?

Answer 19

T cells become activated by streptococcal antigens and contribute to tissue damage.

Question 20

What is the typical histopathologic damage to the myocardium in ARF?

Answer 20

Little histopathologic damage; myocyte necrosis is uncommon.

Question 21

What is the common clinical manifestation of migratory polyarthritis in ARF?

Answer 21

Swelling with serous effusion in the joints.

Question 22

What is the primary focus of ARF-induced damage?

Answer 22

Endothelium and subendothelial and perivascular connective tissue.

Question 23

What is the significance of the M-protein in the pathogenesis of ARF?

Answer 23

It can trigger cross-reactive antibodies and T-cell responses.

Question 24

What are verrucae in the context of rheumatic heart disease?

Answer 24

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.

Question 25

What is Libman-Sacks endocarditis (LSE)?

Answer 25

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.

Question 26

How does rheumatic vegetative endocarditis differ from non-bacterial thrombotic endocarditis (NBTE) and infective endocarditis (IE)?

Answer 26

Both types of rheumatic vegetative endocarditis are distinct in their patterns compared to NBTE and IE.

Question 27

What occurs to the valve tissue during the repair process after rheumatic fever?

Answer 27

Involves ingrowth of blood vessels (neovascularization) and deposition of collagen.

Question 28

What is the earliest manifestation of acute rheumatic fever (ARF)?

Answer 28

Arthritis.

Question 29

Which joints are commonly involved in arthritis associated with rheumatic fever?

Answer 29

Larger joints of the extremities, with occasional involvement of smaller joints in the hands and feet.

Question 30

What are Aschoff bodies?

Answer 30

Granulomatous lesions that result from autoimmune injury in rheumatic fever.

Question 31

What are the long-term effects of acute rheumatic fever on the heart?

Answer 31

Can lead to chronic rheumatic heart disease, characterized by stenosis and regurgitation of the mitral and/or aortic valves.

Question 32

What characterizes Sydenham chorea?

Answer 32

A late manifestation of ARF with involuntary movements involving the face and extremities, often associated with emotional lability.

Question 33

What is the role of echocardiography in diagnosing rheumatic carditis?

Answer 33

It can document valvular regurgitation and detect subclinical carditis.

Question 34

What are the major criteria for diagnosing acute rheumatic fever according to Jones criteria?

Answer 34

* Carditis * Chorea * Subcutaneous nodules * Migratory arthritis involving large joints * Erythema marginatum.

Question 35

What are the minor criteria for diagnosing acute rheumatic fever?

Answer 35

* Arthralgia * Fever * Prolonged PR interval * Elevated inflammatory markers.

Question 36

True or False: Carditis is the only manifestation of rheumatic fever that leads to permanent deformity.

Answer 36

True.

Question 37

What is a characteristic feature of the inflammation seen in rheumatic heart disease?

Answer 37

The presence of neovascularization and thick-walled blood vessels in the valve leaflets.

Question 38

What is the typical duration for arthritis in rheumatic fever?

Answer 38

Usually resolves in 3-4 weeks, even without treatment.

Question 39

What is the significance of an elevated antistreptolysin O (ASO) titer in diagnosing rheumatic fever?

Answer 39

It indicates previous streptococcal infection and is a prerequisite for diagnosis.

Question 40

What is the recommended change in the Jones criteria regarding subclinical carditis?

Answer 40

It should be considered a major criterion.

Question 41

What is a common histological finding in myocarditis associated with rheumatic fever?

Answer 41

Minimal myocyte damage.

Question 42

What is the typical presentation of rheumatic pericarditis?

Answer 42

Evanescent pericardial friction rub, often associated with severe carditis.

Question 43

What can mask the underlying valvular murmurs in rheumatic pericarditis?

Answer 43

A pericardial rub.

Question 44

What is the clinical significance of post-streptococcal arthropathy?

Answer 44

Characterized by recurrent, severe, prolonged polyarthritis that is not very responsive to nonsteroidal anti-inflammatory agents.

Question 45

What types of valve diseases are most commonly seen in rheumatic fever?

Answer 45

* Mitral valve disease (70% of cases) * Aortic valve disease (5-8% of cases).

Question 46

Fill in the blank: The inflammatory changes in the aortic valves can result in _______.

Answer 46

aortic regurgitation.

Question 47

What is the relationship between chronic rheumatic heart disease and systemic lupus erythematosus?

Answer 47

They share similar pathologic features.

Question 48

What is the migratory character of joint pain in rheumatic fever?

Answer 48

Joints are inflamed at different times and for various intervals.

Question 49

What is the typical appearance of erythema marginatum?

Answer 49

Serpiginous, macular, non-pruritic, and evanescent rash on the trunk and proximal extremities.

Question 50

What viral syndromes are associated with carditis?

Answer 50

Coxsackie B virus, Lyme disease, Kawasaki infection ## Footnote These conditions can lead to inflammatory abnormalities of the heart valves.

Question 51

Which collagen diseases may confuse the diagnosis of carditis?

Answer 51

Systemic lupus erythematosus, rheumatoid arthritis ## Footnote These diseases can present early manifestations that mimic carditis.

Question 52

What is the prerequisite for the diagnosis of rheumatic fever (RF)?

Answer 52

Evidence of previous streptococcal infection ## Footnote RF is a postinfectious immunologic complication.

Question 53

What are the commonly used antibody tests for streptococcal infection?

Answer 53

* ASO (Antistreptolysin O) * Anti-DNase B * Hyaluronidase * Streptokinase * Nicotinamide adenine dinucleotide (NAD) ## Footnote These tests help assess recent streptococcal infections.

Question 54

What ASO level is generally used for diagnosis in adults?

Answer 54

More than 240 U ## Footnote For children, the threshold is more than 330 U.

Question 55

What can ST-segment changes in an electrocardiogram indicate in patients with RF?

Answer 55

Pericarditis ## Footnote Repolarization abnormalities may indicate myocarditis.

Question 56

What is the role of echocardiography in diagnosing RF?

Answer 56

Diagnosing and monitoring cardiac structure and function ## Footnote It helps identify valve regurgitation and assess cardiac damage.

Question 57

In developing countries, what is a major challenge in diagnosing RF?

Answer 57

Limited access to medical care ## Footnote Patients often present with recurrences and established heart disease.

Question 58

What is the significance of echocardiography in patients with advanced RF disease?

Answer 58

Its incremental diagnostic benefit is questionable ## Footnote Many echodetectable cases are also clinically detected within a short follow-up.

Question 59

What is the primary objective in treating acute RF?

Answer 59

Eliminating the offending streptococci with antibiotic therapy ## Footnote Penicillin is the agent of choice.

Question 60

What is a common adverse prognostic indicator in RF patients?

Answer 60

Congestive heart failure (CHF) ## Footnote CHF that does not improve with treatment is associated with the worst prognosis.

Question 61

What valvular lesion may develop late after an acute RF infection?

Answer 61

Mitral stenosis ## Footnote Symptoms often appear only after 20 years, with complications like atrial fibrillation.

Question 62

Fill in the blank: The antibody response to various streptococcal antigens develops within the first month and remains detectable for _______.

Answer 62

3–6 months

Question 63

True or False: Echocardiography is universally beneficial for diagnosing RF in developed countries.

Answer 63

False ## Footnote Its routine use has not improved prophylaxis adherence.

Question 64

What is the consequence of valve dysfunction in RF patients?

Answer 64

Risk for subacute bacterial endocarditis ## Footnote Prophylactic antibiotics are recommended before procedures.