Rheumatic Fever Pathophysiology

Pathophysiology

• Rheumatic fever is an inflammatory disease that occurs as a result of an autoimmune response to a group A streptococcal (GAS) infection.
• The immune system mistakenly attacks the body's own tissues, particularly the heart, joints, and skin.
• The inflammatory response leads to the activation of various immune cells, such as T cells and macrophages, which release cytokines and chemokines that cause tissue damage.
• The heart valves are commonly affected, leading to valvulitis and subsequent scarring.

Diagnosis

• Diagnosis is based on a combination of clinical features, laboratory tests, and echocardiography.
• Jones Criteria are used to diagnose acute rheumatic fever (ARF) and are divided into major and minor criteria.
• Major criteria:
  • Carditis
  • Arthritis
  • Chorea
  • Erythema marginatum
  • Subcutaneous nodules
• Minor criteria:
  • Fever
  • Arthralgia
  • Elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP)
  • Prolonged PR interval on electrocardiogram (ECG)

Complications

• Rheumatic heart disease (RHD): the most common complication, resulting in scarring of the heart valves and potentially leading to heart failure.
• Heart valve damage: can lead to mitral regurgitation, mitral stenosis, aortic regurgitation, or aortic stenosis.
• Increased risk of endocarditis: due to the damaged heart valves.
• Recurrent episodes of ARF: can lead to further heart damage and increased risk of complications.

Treatment

• Primary prevention: treating GAS infections with antibiotics to prevent ARF.
• Secondary prevention: regular antibiotic prophylaxis to prevent recurrent episodes of ARF.
• Treatment of ARF:
  • Anti-inflammatory medications (e.g., aspirin, corticosteroids) to reduce inflammation and relieve symptoms.
  • Antibiotics to eradicate any remaining GAS infection.
  • Bed rest and supportive care.

Jones Criteria

• Developed by T. Duckett Jones in 1944 to diagnose acute rheumatic fever (ARF).
• Major criteria:
  • Carditis (inflammation of the heart)
  • Arthritis (inflammation of the joints)
  • Chorea (involuntary movements)
  • Erythema marginatum (a characteristic rash)
  • Subcutaneous nodules (small, painless bumps under the skin)
• Minor criteria:
  • Fever
  • Arthralgia (joint pain)
  • Elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP)
  • Prolonged PR interval on electrocardiogram (ECG)
• Diagnosis of ARF requires:
  • Two major criteria
  • One major criterion and two minor criteria
  • Three minor criteria

Pathophysiology

• Rheumatic fever is an inflammatory disease caused by an autoimmune response to group A streptococcal (GAS) infection, leading to mistaken attacks on the body's own tissues, especially the heart, joints, and skin.
• The inflammatory response activates immune cells, releasing cytokines and chemokines that cause tissue damage.
• Heart valves are commonly affected, leading to valvulitis and scarring.

Diagnosis

• Diagnosis is based on clinical features, laboratory tests, and echocardiography.
• Jones Criteria are used to diagnose acute rheumatic fever (ARF), divided into major and minor criteria.
• Major criteria include carditis, arthritis, chorea, erythema marginatum, and subcutaneous nodules.
• Minor criteria include fever, arthralgia, elevated ESR or CRP, and prolonged PR interval on ECG.

Complications

• Rheumatic heart disease (RHD) is the most common complication, resulting in scarring of heart valves and potentially leading to heart failure.
• Heart valve damage can lead to mitral regurgitation, mitral stenosis, aortic regurgitation, or aortic stenosis.
• There is an increased risk of endocarditis due to damaged heart valves.
• Recurrent episodes of ARF can lead to further heart damage and increased risk of complications.

Treatment

• Primary prevention involves treating GAS infections with antibiotics to prevent ARF.
• Secondary prevention involves regular antibiotic prophylaxis to prevent recurrent episodes of ARF.
• Treatment of ARF includes anti-inflammatory medications, antibiotics, bed rest, and supportive care.

Jones Criteria

• Developed by T. Duckett Jones in 1944 to diagnose acute rheumatic fever (ARF).
• Jones Criteria require two major criteria, one major criterion and two minor criteria, or three minor criteria for diagnosis.