Acute Rheumatic Fever (ARF)

What is Acute Rheumatic Fever (ARF) according to the summary?

ARF is an inflammatory sequela involving the heart, joints, skin, and CNS that occurs two to four weeks after an untreated group A β‑hemolytic streptococcal (GAS) infection. Summary 1

What pathogenic mechanism is thought to cause Acute Rheumatic Fever (ARF)?

Molecular mimicry between streptococcal M protein and human cardiac myosin proteins, causing antibodies and T cells activated against GAS to react with human proteins, leading to tissue injury and inflammation. Summary / Pathophysiology 2

What are the characteristic clinical features of Acute Rheumatic Fever (ARF) besides nonspecific symptoms?

Symptoms involving the heart (carditis/valvulitis), joints (migratory polyarthritis), skin (subcutaneous nodules, erythema marginatum), and/or CNS (Sydenham chorea). Summary / Clinical 3

How is Acute Rheumatic Fever (ARF) primarily diagnosed?

Diagnosis is primarily clinical and based on the Jones criteria. Summary / Diagnosis 4

What diagnostic findings typically support an Acute Rheumatic Fever (ARF) diagnosis?

Elevated inflammatory markers, positive antistreptococcal antibodies, and valvular damage on echocardiogram typically support the diagnosis. Summary / Diagnosis 5

What does the treatment of Acute Rheumatic Fever (ARF) include?

Treatment includes antibiotic therapy for GAS eradication, symptom-based treatment (e.g., for arthritis), and management of associated complications. Summary / Treatment 6

What is the main potential long-term cardiac complication of Acute Rheumatic Fever (ARF)?

Progressive, permanent damage to the heart valves (especially mitral), resulting in chronic rheumatic heart disease (RHD). Summary / Complications 7

What is required long-term after an episode of Acute Rheumatic Fever (ARF)?

Long-term antibiotic prophylaxis and monitoring are recommended in all patients with ARF and RHD to prevent ARF recurrence and RHD progression. Summary / Prevention 8

How is Acute Rheumatic Fever (ARF) formally defined?

ARF is a delayed inflammatory complication of group A β‑hemolytic streptococcal infection, usually occurring within 1-5 weeks after the acute infection. Definitions 9

How is Rheumatic Carditis defined?

A manifestation of ARF that includes acute pancarditis and/or valvulitis. Definitions 10

How is Rheumatic Heart Disease (RHD) defined?

Chronic cardiac valvular or muscle damage as a complication of ARF. Definitions 11

What is the peak age incidence for Acute Rheumatic Fever (ARF)?

Peak incidence is between 5-15 years of age. Epidemiology 12

What infection precedes Acute Rheumatic Fever (ARF)?

Previous infection with group A β‑hemolytic streptococcus (GAS), also referred to as Streptococcus pyogenes. Etiology 13

What type of GAS infection most commonly precedes Acute Rheumatic Fever (ARF)?

Usually acute tonsillitis or pharyngitis ("strep throat"). Etiology 14

Can Acute Rheumatic Fever (ARF) occur after GAS skin infections?

Yes, ARF may occur after GAS infections of the skin (e.g., erysipelas, impetigo, cellulitis) but this is less common than poststreptococcal glomerulonephritis following skin infections. Etiology 15

What is the most commonly accepted pathophysiological mechanism for Acute Rheumatic Fever (ARF)?

Untreated GAS tonsillitis/pharyngitis → antibodies against streptococcal M protein → cross-reaction with nerve/myocardial proteins (e.g., myosins) via molecular mimicry → type II hypersensitivity reaction → inflammation. Pathophysiology 16

What is the characteristic histological finding in the myocardium during Acute Rheumatic Fever (ARF)?

Aschoff bodies, which are granulomas of rheumatic inflammation. Pathology 17

What cells are found within Aschoff bodies in Acute Rheumatic Fever (ARF)?

Aschoff bodies contain multinucleated giant cells (Aschoff cells), other inflammatory cells (mononuclear cells, plasma cells, T lymphocytes), and characteristic cardiac histiocytes called Anitschkow cells. Pathology 18

Describe the appearance of Anitschkow cells seen in Aschoff bodies.

Large, elongated mononuclear cells (cardiac histiocytes) with an ovoid nucleus containing wavy, caterpillar-like chromatin (longitudinal view) or an owl-eye appearance (transverse view). Pathology 19

When do clinical features of Acute Rheumatic Fever (ARF) typically manifest after GAS infection?

Features usually manifest within 1-5 weeks following a GAS infection. Clinical Features 20

What type of arthritis is characteristic of Acute Rheumatic Fever (ARF)?

Migratory polyarthritis, primarily involving the large joints. Clinical Features 21

What layers of the heart can be affected in Acute Rheumatic Fever (ARF) carditis?

Pancarditis can occur, affecting the endocardium, myocardium, and pericardium. Clinical Features 22

Which heart valve is most commonly affected in Acute Rheumatic Fever (ARF)?

The mitral valve is most commonly affected (∼ 65% of cases). Clinical Features 23

What are the early and late manifestations of mitral valve involvement in rheumatic heart disease?

Early: mitral regurgitation or prolapse. Late: mitral stenosis (ARF is the most frequent cause). Mixed disease can also occur. Clinical Features 24

What other valves besides the mitral valve are commonly affected in Acute Rheumatic Fever (ARF)?

The aortic valve (~25%, causing regurgitation early, stenosis late) and tricuspid valve (~10%) are also affected. Clinical Features 25

What CNS manifestation is characteristic of Acute Rheumatic Fever (ARF)?

Sydenham chorea, characterized by involuntary, irregular, nonrepetitive movements of the limbs, neck, head, and/or face. Clinical Features 26

When does Sydenham chorea typically manifest after the initial GAS infection?

Sydenham chorea typically manifests later, occurring 1-8 months after the inciting infection. Clinical Features 27

Describe the "milkmaid grip" seen in Sydenham chorea.

Inability to maintain muscle contraction in the hands, resulting in intermittent loss of contraction causing alternating squeeze and release ("milking"). Clinical Features 28

Describe the "choreic hand" seen in Sydenham chorea.

Intermittent wrist flexion with extension of the digits ("spooning" of the hand). Clinical Features 29

What neuropsychiatric symptoms can accompany Sydenham chorea?

Inappropriate laughing/crying, agitation, anxiety, apathy, and obsessive-compulsive behavior can occur. Clinical Features 30

What skin finding in Acute Rheumatic Fever (ARF) consists of painless lumps over bony prominences or tendons?

Subcutaneous nodules. Clinical Features 31

Describe Erythema marginatum, a skin finding in Acute Rheumatic Fever (ARF).

A centrifugally expanding pink or light red rash with a well-defined outer border and central clearing; painless, nonpruritic, located on trunk/limbs (spares face), may rapidly appear/disappear. Clinical Features 32

What is the mnemonic using "JONES" criteria for Acute Rheumatic Fever symptoms?

J = Joints (migratory polyarthritis), ♥ (heart) = Pancarditis, N = Nodules (subcutaneous), E = Erythema marginatum, S = Sydenham chorea. Clinical Features 33

What general principles guide the diagnosis of Acute Rheumatic Fever (ARF)?

Evaluate for preceding GAS infection (culture, antigen, antibody); use revised Jones criteria; perform cardiac workup (ECG, echo) on all suspected/confirmed cases. Diagnosis 34

According to the revised Jones criteria, what is required to diagnose an initial episode of ARF with GAS evidence?

Two major criteria OR one major plus two minor criteria. Diagnosis 35

According to the revised Jones criteria, what is required to diagnose a recurrent episode of ARF with GAS evidence?

Either the same as initial episode (2 major OR 1 major + 2 minor) OR the presence of three minor criteria. Diagnosis 36

List the 5 MAJOR Jones criteria for Acute Rheumatic Fever (ARF).

Migratory polyarthritis (or monoarthritis/polyarthralgia in high-risk pops), Carditis, Sydenham chorea, Subcutaneous nodules, Erythema marginatum. Diagnosis 37

List the 4 MINOR Jones criteria for Acute Rheumatic Fever (ARF).

Arthralgia (poly- or mono-), Fever (≥38.5°C or ≥38°C), Elevated acute phase reactants (ESR/CRP thresholds vary by risk), Prolonged PR interval on ECG. Diagnosis 38

What laboratory tests confirm a preceding GAS infection for diagnosing Acute Rheumatic Fever (ARF)?

Elevated/rising Antistreptolysin O (ASO) titer, elevated/rising Anti-DNase B (ADB) titer, positive throat culture, OR positive rapid GAS antigen test. Diagnosis 39

What is the most common ECG finding in Acute Rheumatic Fever (ARF)?

Prolonged PR interval (first-degree AV block). Diagnosis / Cardiac 40

Besides prolonged PR interval, what other ECG findings might occur in Acute Rheumatic Fever (ARF)?

Second-degree AV block, complete heart block, sinus tachycardia, accelerated junctional rhythm, or ECG features of pericarditis. Diagnosis / Cardiac 41

What are characteristic echocardiographic findings in acute rheumatic carditis?

Features of rheumatic valvulitis, such as mitral regurgitation or aortic regurgitation. Diagnosis / Cardiac 42

What is a characteristic echocardiographic finding in chronic rheumatic heart disease?

Mitral stenosis. Diagnosis / Cardiac 43

What findings might a chest x-ray show in rheumatic heart disease?

Enlarged left atrium, enlarged left ventricle, or x-ray findings of pulmonary edema. Diagnosis / Cardiac 44

Is neuroimaging routinely indicated for diagnosing Sydenham chorea?

No, neuroimaging (MRI or CT brain) is not routinely indicated as the diagnosis is based on clinical and laboratory findings. Diagnosis / Neuro 45

What cardiac test should be obtained in all patients with Sydenham chorea?

Echocardiography should be obtained because concurrent cardiac involvement is common. Diagnosis / Neuro 46

What is the first step in treating Acute Rheumatic Fever (ARF)?

Antibiotic therapy for GAS eradication. Treatment 47

What is the first-line antibiotic regimen for GAS eradication after pharyngitis in Acute Rheumatic Fever (ARF)?

Oral penicillin V or intramuscular (IM) penicillin G. Treatment 48

What antibiotics are used for GAS eradication in ARF patients with penicillin allergy?

Cephalosporins (if hypersensitivity without anaphylaxis) OR macrolides (if severe hypersensitivity to beta-lactams). Treatment 49

What medications are used for symptomatic treatment of arthritis and fever in confirmed Acute Rheumatic Fever (ARF)?

NSAIDs (Naproxen or ibuprofen preferred in children) or Aspirin. Treatment 50

Does anti-inflammatory treatment for ARF symptoms prevent progression to Rheumatic Heart Disease (RHD)?

There is insufficient evidence to recommend anti-inflammatory drugs specifically to prevent progression to RHD, although they relieve symptoms. Treatment 51

When should screening for Rheumatic Heart Disease (RHD) be considered?

Consider in populations or areas with a moderate or high risk of RHD. Mgmt Complications / RHD 52

How is screening for Rheumatic Heart Disease (RHD) performed and in which groups?

Screening uses echocardiography. Recommended groups include pregnant individuals and children aged 5-19 years in moderate/high-risk areas. Mgmt Complications / RHD 53

What are the key components of managing established Rheumatic Heart Disease (RHD)?

Antibiotic prophylaxis (prevent recurrence), manage complications (HF, AFib anticoagulation, endocarditis prophylaxis/treatment), possible valvuloplasty/valve replacement, long-term echo follow-up. Mgmt Complications / RHD 54

How is Sydenham chorea typically managed?

It is usually self-limited; supportive therapy (rest, calm environment, education) is indicated for all. Pharmacotherapy (carbamazepine, valproic acid) considered for severe symptoms impacting daily activities. Mgmt Complications / SC 55

When should long-term antibiotic prophylaxis begin after an episode of Acute Rheumatic Fever (ARF)?

Immediately after completion of the initial antibiotic therapy for GAS eradication. Prevention Recurrence 56

What is the first-line agent for long-term antibiotic prophylaxis to prevent ARF recurrence?

Intramuscular (IM) penicillin G benzathine every 4 weeks. Prevention Recurrence 57

What are alternatives for long-term antibiotic prophylaxis if IM penicillin G is not feasible or allergy exists?

Oral penicillin V; or Sulfadiazine or oral macrolides for confirmed penicillin allergy. Prevention Recurrence 58

How long should antibiotic prophylaxis continue for ARF without carditis?

For 5 years or until the patient reaches 21 years of age (whichever is longer). Prevention Recurrence 59

How long should antibiotic prophylaxis continue for ARF with carditis but without residual heart disease?

For 10 years or until the patient reaches 21 years of age (whichever is longer). Prevention Recurrence 60

How long should antibiotic prophylaxis continue for ARF with carditis and permanent valvular heart defects (RHD)?

For 10 years or until the patient reaches 40 years of age (whichever is longer); potentially lifelong in high-risk individuals. Prevention Recurrence 61

What is the most important prognostic factor in Acute Rheumatic Fever (ARF)?

Cardiac involvement (carditis). Prognosis 62

What typically causes early death from Acute Rheumatic Fever (ARF)?

Early death is usually due to myocarditis rather than valvular defects. Prognosis 63

How can Acute Rheumatic Fever (ARF) be primarily prevented?

Initiate antibiotic treatment promptly for GAS infections, such as GAS tonsillopharyngitis (e.g., with penicillin V) or skin/soft tissue infections. Prevention (Primary) 64