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What is the duration of acute rheumatic fever in most patients?
Which of the following investigations is NOT commonly performed in cases of acute rheumatic fever?
What complication is considered an early complication of acute rheumatic fever?
Which of the following markers is NOT indicated as part of laboratory investigations for acute rheumatic fever?
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According to the Jones Criteria, what is required for the diagnosis of acute rheumatic fever?
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What indicates a recent streptococcal infection in adults regarding antistreptolysin O titer (ASO)?
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Which of the following symptoms may be present in a patient with acute rheumatic fever?
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What is the primary aim of treating acute rheumatic fever?
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What is the primary reason that rheumatic carditis does not resolve without residual effects?
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Which symptom is a key indicator of acute carditis related to rheumatic fever?
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Which part of the heart is NOT typically involved in rheumatic carditis?
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What characteristic is associated with erythema marginatum?
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Which manifestation is common in patients with rheumatic fever involving the heart muscle?
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What differentiates rheumatic fever's effect on the joints versus the heart?
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Subcutaneous nodules associated with rheumatic fever are described as:
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Which condition is characterized by fast, jerky, involuntary movements, and may be associated with rheumatic fever?
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Which type of inflammatory lesion is characterized by a central area of fibrinoid degeneration surrounded by lymphocytes?
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What is the most common age of onset for acute rheumatic fever?
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Which of the following is NOT a major criterion for diagnosing acute rheumatic fever?
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Which statement regarding rheumatic arthritis is correct?
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What is a common symptom of rheumatic carditis?
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In which layer of the heart does the myocardium belong?
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Which of the following contributes to the transmission of upper respiratory tract infections?
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What characterizes arthralgia compared to arthritis?
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What type of infection commonly precedes rheumatic fever?
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What plays a significant role in the pathogenesis of rheumatic fever?
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How long is the typical latent period between a streptococcal infection and the onset of rheumatic fever?
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What is the primary mechanism thought to contribute to the development of rheumatic fever?
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Which of the following tissues is least affected by rheumatic fever?
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Why do only a minority of individuals develop rheumatic fever after a streptococcal infection?
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Rheumatic fever is classified as what type of disorder?
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Which characteristic best describes rheumatic fever?
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What is the primary proposed mechanism by which rheumatic fever develops following a streptococcal infection?
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Which clinical feature is most strongly associated with the autoimmune nature of rheumatic fever?
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What is the latent period between streptococcal infection and the onset of rheumatic fever for most patients?
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Which group of tissues is primarily affected by rheumatic fever?
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What factor may contribute to why certain individuals develop rheumatic fever following infection?
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Which bacterial strain is most likely to trigger rheumatic fever?
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What mechanism explains the damage to distant tissues in rheumatic fever?
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Which of the following is NOT characteristic of rheumatic fever?
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Which factor is associated with the theory of molecular mimicry in rheumatic fever?
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What is the primary reason that rheumatic arthritis leads to joint inflammation?
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Which of the following is a characteristic of proliferative lesions in rheumatic fever?
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What kind of arthritis is most commonly presented in acute rheumatic fever?
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What best describes the clinical feature of rheumatic chorea?
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Which factor contributes to the incidence of acute rheumatic fever in populations?
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In which layer of the heart is fibrinoid degeneration observed in rheumatic carditis?
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Which clinical presentation can indicate the severity of cardiac involvement in acute rheumatic fever?
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What is one of the major criteria for diagnosing rheumatic fever?
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Which inflammatory reaction is marked by a central area of degeneration surrounded by immune cells?
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What distinguishes arthritis from arthralgia in the context of rheumatic fever?
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What is a common laboratory finding in patients with acute rheumatic fever?
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Which of the following is considered a late complication of acute rheumatic fever?
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Which laboratory test is indicative of a recent streptococcal infection?
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Which statement accurately describes the diagnosis process for acute rheumatic fever?
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What type of anemia is commonly observed in patients with acute rheumatic fever?
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What is the significance of elevated erythrocyte sedimentation rate (ESR) in lab investigations?
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Which of the following is NOT considered an early complication of acute rheumatic fever?
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What is the effect of rheumatic activity in the body?
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Which investigation is least likely to be positive in cases of acute rheumatic fever?
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Which aspect of acute rheumatic fever is characterized by the absence of specific diagnostic tests?
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What is one of the primary outcomes of the gradual fibrosis process in rheumatic carditis?
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Which sign can indicate the involvement of myocarditis in rheumatic carditis?
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What characterizes erythema marginatum associated with rheumatic fever?
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Which type of heart complication is most directly related to rheumatic carditis?
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What symptom is commonly associated with the pericardial involvement in rheumatic carditis?
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Which statement correctly describes the subcutaneous nodules associated with rheumatic fever?
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What type of involuntary movements is characteristic of rheumatic chorea?
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What differentiates the effects of rheumatic fever on joints versus the heart?
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What is a common misconception regarding the onset of rheumatic fever symptoms?
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Which statement about the nature of carditis in rheumatic fever is accurate?
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Study Notes
Rheumatic Fever
- A sequel to group A β-hemolytic streptococcal pharyngeal infection (rheumatogenic strain)
- Follows infection of upper respiratory tract especially pharyngitis
- More likely to occur after severe & recurrent infections
- Not communicable, but caused by a communicable disease
Pathogenesis of Rheumatic Fever
- Molecular mimicry: Molecular similarity between M protein of infecting streptococcus and human tissues like heart, joints, brain, connective tissue
- The trigger is an autoimmune response
- Antibodies produced against streptococci cross-react with human tissues
- Damage to tissues is not due to direct bacterial invasion but an autoimmune reaction
- Latent period between infection and onset is 1-5 weeks except in chorea, which may occur after several months
- Occurs in a minority of patients after streptococcal infection, host immune responses likely play a role
Clinical Presentation of Rheumatic Fever
-
Major Criteria:
- Arthritis
- Carditis
- Rheumatic chorea (Sydenham’s)
- Subcutaneous nodules
- Erythema marginatum
-
Minor Criteria:
- Fever
- Arthralgia
- History of rheumatic fever or evidence of rheumatic heart disease
- Elevated ESR, C-reactive protein, polymorphonuclear leucocytosis
- Prolonged P-R interval (>0.22s)
Rheumatic Arthritis
- Most common presentation
- Characterized by:
- Polyarthritis
- Migratory or fleeting character
- Predilection for large joints (knees, ankles, elbows, wrists)
- Dramatic response to salicylates within 24-48 hours
- Complete recovery with no residual deformities
Rheumatic Carditis
- Most serious manifestation
- Can lead to chronic rheumatic heart disease & severe heart failure
- Unlike arthritis, carditis does not resolve without residue effects
- Gradual fibrosis progresses, leading to valvular stenosis and irreversible damage
- Involvement of all layers of the heart: Pericardium, myocardium, endocardium (Pancarditis)
Manifestations of Rheumatic Carditis
- Disproportionate tachycardia, especially if associated with weak or muffled first heart sound
- Rapid development of functional murmurs
- Abnormal third heart sound due to myocarditis
- Pericardial rub due to pericarditis or pericardial effusion
- Heart failure in severe cases
Subcutaneous Nodules
- Small, mobile, painless nodules
- Firm, non-tender, isolated or in clusters
- Most common along extensor surface of joints, bony prominences, tendons, dorsal surface of feet
- Last a few days, with complete resolution
Erythema Marginatum
- Highly specific to acute rheumatic fever
- Erythematous macules with migratory borders and blanching centers (reddish pink border, pale center)
- Round or irregular shape
- Often on the trunk, abdomen, inner arms, or thighs
- Highly suggestive of carditis
Rheumatic (Sydenham's) Chorea
- Extrapyramidal disorder (affecting basal ganglia)
- Fast, jerky, involuntary, purposeless movements especially face, tongue and limbs (hands & feet)
- Involuntary movements increase with stress
- Emotional instability may be associated, but mentality remains normal
- May be the only manifestation of ARF
- Usually a late manifestation, months after infection
- Occurs in 30% of patients with ARF
- Affects females more than males
- Long duration (several months) but resolves completely with no cerebral damage
Investigations for Rheumatic Fever
-
Laboratory Investigations:
- CBC: Leukocytosis and anemia
- ESR: Markedly elevated, non-specific
- CRP : Markedly elevated, non-specific
- ASO: Elevated in 80% of cases, >250 Todd units/ml in adults & 500 Todd units/ml in children (indicative of recent streptococcal infection)
- Streptozyme test: Positive in more than 95% of cases
- Throat culture: Positive in only few cases
-
Cardiac Investigations:
- ECG
- Chest X-ray
- Echocardiography
Diagnosis of Acute Rheumatic Fever
- Jones Criteria: Developed to prevent overdiagnosis
- Diagnosis requires presence of two major criteria or one major and two minor criteria, in the presence of data of recent streptococcal infection
-
Evidence of Streptococcal Infection:
- History of sore throat 2-3 weeks before
- Residual infection in throat at examination
- Positive throat swab culture
- Elevated ASO titer (>250 Todd units/ml)
- History of recent scarlet fever
Aim of Treatment
- Eradication of group A β-hemolytic streptococcus infection
- Avoid chronic exposure of immune system to streptococcal bacteria
- Treatment according to presentation
Complications of Rheumatic Fever
-
Early Complications:
- Heart failure
- Arrhythmias
- Heart Block
-
Late Complications:
- Rheumatic valvular lesions (e.g mitral stenosis)
- Rheumatic activity
- Rarely; adhesive pericarditis & Jaccoud’s arthropathy
Rheumatic Fever
- Preceded by infection with group A B-hemolytic streptococci, particularly pharyngitis.
- More likely to develop after severe and recurrent infections.
- The mechanism of rheumatic fever development is unknown, but the prevailing theory suggests an autoimmune process.
Pathogenesis
- An autoimmune response is triggered by molecular mimicry between M protein of the infecting streptococcus and human tissues like the heart, joints, brain, and connective tissue.
- The body produces antibodies against streptococci.
- These antibodies cross-react with human tissues due to antigenic similarity between streptococcal components and human connective tissues.
- The damage to tissues is not due to direct bacterial invasion but to an autoimmune reaction caused by anti-streptococcal antibodies cross-reacting with host tissues.
- The latent period between streptococcal infection and rheumatic fever onset is 1-5 weeks, except for chorea, which may occur after several months.
Factors Influencing Development
- Host immune responses may play a role in determining who develops rheumatic fever after streptococcal infection.
- The virulence of the streptococcal strain (rheumatogenic serotype) is a significant factor.
Definition
- Rheumatic fever is an inflammatory disorder caused by an immune response to group A-beta hemolytic streptococcal pharyngeal infection (rheumatogenic strain).
- It affects connective tissue, particularly the heart, joints, brain, and skin (cutaneous and subcutaneous tissue).
- It is not a communicable disease, but rather a consequence of a communicable disease (streptococcal pharyngitis).
Pathology
- Involves inflammatory processes in joints, heart, CNS, and skin & subcutaneous nodules.
- Two types of inflammatory reactions occur:
- Exudative lesions mainly affect serous membranes and heal without residual effects.
- Proliferative lesions ("Aschoff nodules") primarily affect the heart and consist of a central area of fibrinoid degeneration surrounded by lymphocytes, macrophages, Aschoff giant cells, and an outer layer of fibroblasts. They heal with fibrosis.
Epidemiology
- Incidence and mortality have declined in the past 30 years due to:
- Improved socioeconomic conditions.
- Rapid diagnosis and treatment of strep pharyngitis with effective antibiotics.
- Commonest age of onset is 5-15 years, but it can occur up to 25-30 years.
- Males and females are equally affected.
- Overcrowding, poverty, and lack of access to medical care contribute to the transmission of upper respiratory tract (URT) infections.
Clinical Presentation
- Major criteria include Arthritis, Carditis, Rheumatic chorea (Sydenham's), Subcutaneous nodules, and Erythema marginatum.
- Minor criteria include Fever, Arthralgia, History of rheumatic fever or evidence of rheumatic heart disease, Acute phase reactants (high ESR, C-reactive protein, polymorphnuclear leucocytosis), and Prolonged P-R interval more than 0.22 sec.
Rheumatic Arthritis
- Most common presentation of rheumatic fever.
- Characterized by:
- Polyarthritis.
- Migratory or fleeting character.
- Predilection for large joints.
- Dramatic response to salicylates within 24-48 hours.
- Complete recovery with no residual deformities.
Arthralgia vs. Arthritis
- Arthritis is inflammation of the joint, presenting with all signs of inflammation (redness, heat, swelling, pain, tenderness, and limited movement). It is a major criteria of rheumatic fever.
- Arthralgia is joint pain without signs of inflammation. It is a minor criteria of rheumatic fever.
Rheumatic Carditis
- Most serious manifestation of rheumatic fever.
- May lead to chronic rheumatic heart disease and severe heart failure.
- Unlike arthritis, carditis does not resolve without residual effects.
- Gradually progresses with slow fibrosis, leading to irreversible stenosis.
- Rheumatic fever can be gentle on joints but harsh on the heart (the saying "rheumatic fever licks the joints and bites the heart").
Rheumatic Carditis (cont.)
- All layers of the heart may be involved (pancarditis).
- Symptoms and signs depend on the involvement of the pericardium, myocardium, or endocardium.
Manifestations of Rheumatic Carditis
- Early signs:
- Disproportionate tachycardia, particularly with a weak or muffled first heart sound and prolonged P-R interval.
- Rapid development of functional murmurs.
- Abnormal third heart sound due to myocarditis.
- Pericardial rub due to pericarditis or pericardial effusion.
- Severe cases may present with heart failure due to myocardial damage.
Subcutaneous Nodules
- Usually small, mobile, painless nodules.
- Firm, non-tender, and isolated or in clusters.
- Most common along extensor surfaces of joints, bony prominences, tendons, and feet.
- Last a few days with complete resolution.
Erythema Marginatum
- Present in 7% of patients.
- Highly specific to rheumatic fever.
- Cutaneous lesion characterized by erythematous macules with migratory borders and blanching centers (reddish pink border, pale center).
- Often found on the trunk, abdomen, inner arms, or thighs.
- Highly suggestive of carditis.
Rheumatic (Sydenham's) Chorea
- Extrapyramidal disorder (affecting basal ganglia).
- Damage is typically not permanent.
- Fast, jerky, involuntary, purposeless movements, particularly affecting the face, tongue, and limbs (hands and feet).
- Involuntary movements increase with stress.
- May be associated with emotional instability, but mentality remains normal.
- Can be the only manifestation of rheumatic fever.
- Usually a late manifestation months after infection.
- Occurs in 30% of patients with rheumatic fever.
- Affects females more than males.
- Lasts for several months but resolves completely without cerebral damage.
Investigations
- Complete blood count (CBC): leukocytosis and anemia.
- Acute phase reactants: elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).
- Anti-streptococcal O titer (ASOT).
- Throat culture.
- Electrocardiogram (ECG).
- Plain chest x-ray.
- Echocardiogram.
Complications
-
Early complications:
- Heart failure.
- Arrhythmias.
- Heart block.
-
Late complications:
- Rheumatic valvular lesions (e.g., mitral stenosis).
- Rheumatic activity.
- Rarely: adhesive pericarditis and Jaccoud's arthropathy.
Laboratory Investigations
-
Blood picture:
- Polymorphnuclear leucocytosis.
- Normocytic anemia.
- Erythrocyte sedimentation rate (ESR): markedly elevated, used for follow-up.
- C-reactive protein (CRP): markedly elevated, used for follow-up.
- Antistreptolysin O titer (ASO): elevated in 80% of cases, with titers greater than 250 Todd units/ml in adults and 500 Todd units/ml in children indicative of recent streptococcal infection.
- Streptozyme test: positive in more than 95% of cases.
- Throat culture: positive in only a few cases.
Cardiac Investigations
- ECG.
- Chest x-ray.
- Echocardiography.
Diagnosis
- No specific diagnostic test exists for acute rheumatic fever.
Jones Criteria
- Developed to prevent overdiagnosis.
- Diagnosis requires:
- Two major criteria or one major and two minor criteria.
- Evidence of recent streptococcal infection.
Evidence of Streptococcal Infection
- History of sore throat 2-3 weeks prior to presentation.
- Sometimes a residual throat infection is present at the time of examination.
- Throat swab culture is often positive for streptococcus.
- Elevated antistreptolysin O titer (ASOT) more than 250 Todd units/ml or other antistreptococcal antibodies.
- History of recent scarlet fever.
Aim of Treatment
- Eradication of group A beta-hemolytic streptococcal infection.
- Avoid chronic exposure of the immune system to streptococcal bacteria.
- Treatment according to the presentation.
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Description
This quiz covers the key aspects of rheumatic fever, including its connection to group A streptococcal infections, the pathogenesis involving molecular mimicry, and the clinical presentation criteria. Understand the autoimmune response and its implications for diagnosis and treatment.
