Question

Acute rheumatic fever. 

Etiology, pathogenesis, clinic, diagnosis, treatment. 

Features of the clinic in children. 

Primary and secondary prevention of rheumatism.

Answer 1

Acute rheumatic fever (ARF) is an inflammatory autoimmune condition that can occur following an untreated or inadequately treated group A streptococcal infection, particularly streptococcal pharyngitis (strep throat). The disease primarily affects children and adolescents and can lead to significant cardiac and systemic complications if not promptly recognized and managed. 

Here's a comprehensive overview covering the etiology, pathogenesis, clinical manifestations, diagnosis, treatment, as well as primary and secondary prevention strategies for acute rheumatic fever:

Etiology:

Acute rheumatic fever is primarily caused by an abnormal immune response to group A Streptococcus pyogenes, a bacterial pathogen responsible for streptococcal infections. The underlying mechanism involves molecular mimicry, where antibodies produced in response to the streptococcal infection cross-react with host tissues, leading to widespread inflammation and tissue damage, particularly in the heart, joints, central nervous system, and skin.

Pathogenesis:

The pathogenesis of acute rheumatic fever involves the activation of the body's immune system in response to certain antigenic components of group A Streptococcus. The resultant immune response leads to the development of autoantibodies targeting specific host tissues, particularly the heart valves, joints, and other organs. This immune-mediated process triggers inflammation, tissue injury, and the characteristic clinical manifestations associated with acute rheumatic fever.

Clinical Manifestations in Children:

1. Cardiac Involvement: 

Acute rheumatic fever often presents with carditis, involving inflammation of the heart structures, particularly the endocardium. Children may develop murmurs, tachycardia, chest pain, and other symptoms of cardiac dysfunction.

2. Arthritis: 

Swollen, painful, and migratory polyarthritis affecting large joints, such as the knees, ankles, elbows, and wrists, is a common feature of acute rheumatic fever in children.

3. Chorea: 

Sydenham chorea, or St. Vitus' dance, is a characteristic neurological manifestation involving involuntary, purposeless movements, emotional lability, and neuropsychiatric symptoms.

4. Subcutaneous Nodules: 

Painful subcutaneous nodules over bony prominences may develop in some children with acute rheumatic fever.

5. Skin Manifestations: 

Erythema marginatum, a pink, non-pruritic rash that typically occurs on the trunk and proximal extremities, is another characteristic skin finding.

Diagnosis:

The diagnosis of acute rheumatic fever in children involves a combination of clinical evaluation, laboratory studies, and evidence of preceding streptococcal infection. Diagnostic criteria typically include the Jones criteria, which encompass major and minor criteria related to specific clinical and laboratory findings. Additionally, serological tests, such as antistreptolysin O (ASO) titers and anti-DNase B titers, are used to confirm recent streptococcal infection.

Echocardiography and other imaging studies may be performed to assess cardiac involvement and monitor for valvular damage.

Treatment:

The primary goals of treatment for acute rheumatic fever in children include addressing the underlying streptococcal infection, managing inflammation, and preventing further cardiac complications. Treatment strategies may include:

Antibiotic therapy: 

Prompt administration of appropriate antibiotics, such as penicillin or other beta-lactam agents, to eliminate the group A Streptococcus infection and prevent recurrences.

Anti-inflammatory medications: 

Nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids may be used to manage arthritis, carditis, and other systemic manifestations of acute rheumatic fever.

Management of carditis: 

Children with significant cardiac involvement may require additional cardiac medications, such as diuretics or other agents to manage heart failure or arrhythmias.

Long-term management often involves the use of antibiotic prophylaxis to prevent recurrent streptococcal infections and the development of chronic rheumatic heart disease.

Primary and Secondary Prevention:

Primary prevention of rheumatic fever in children involves strategies to prevent initial streptococcal infections through measures such as early diagnosis and treatment of streptococcal pharyngitis, promotion of good hand hygiene, and avoiding close contact with individuals with active streptococcal infections.

Secondary prevention focuses on long-term antibiotic prophylaxis to prevent recurrent streptococcal infections in individuals with a history of acute rheumatic fever, particularly those with evidence of cardiac involvement. This may involve regular administration of antibiotics such as benzathine penicillin G to reduce the risk of recurrent streptococcal infections and subsequent rheumatic fever exacerbations.

In summary, acute rheumatic fever is an inflammatory condition associated with group A Streptococcus infection, especially in children, with a range of cardiac, joint, neurological, and cutaneous manifestations. The management of acute rheumatic fever in children involves timely recognition, treatment of streptococcal infections, anti-inflammatory therapy, and long-term antibiotic prophylaxis to prevent recurrences and reduce the risk of chronic rheumatic heart disease. Efforts in primary and secondary prevention are essential to minimize the burden of acute rheumatic fever and its long-term complications in children.