Can scarlet fever cause rheumatic heart disease in children and adolescents?

Can Scarlet Fever Cause Rheumatic Heart Disease?

Yes, scarlet fever can cause rheumatic heart disease because it is a manifestation of Group A Streptococcal (GAS) infection, and any GAS infection—including scarlet fever, pharyngitis, or impetigo—can trigger acute rheumatic fever, which may progress to rheumatic heart disease if untreated or recurrent. 1, 2, 3

The Pathophysiologic Link

Scarlet fever is a delayed, nonsuppurative, autoimmune phenomenon following GAS infection that can lead to acute rheumatic fever through the same mechanism as streptococcal pharyngitis. 2 The key streptococcal infectious diseases associated with ARF and RHD include:

• GAS pharyngeal tonsillitis 3
• Scarlet fever 3
• Impetigo 3
• Obstructive sleep apnea syndrome with chronic GAS colonization 3

All of these GAS manifestations share the same rheumatogenic potential in susceptible individuals. 2, 3

Critical Treatment to Prevent Rheumatic Heart Disease

Immediate antibiotic therapy for scarlet fever is essential to prevent rheumatic fever complications. The American Academy of Pediatrics recommends: 1

• Oral penicillin V: 250 mg twice daily for children, 500 mg 2-3 times daily for adolescents/adults for 10 days 1
• For penicillin-allergic patients: Erythromycin or first-generation cephalosporins (if no immediate-type hypersensitivity) 1
• Patients become non-contagious after 24 hours of antibiotic therapy 1

The Sobering Reality: Treatment Doesn't Guarantee Prevention

Even when scarlet fever or GAS pharyngitis is treated optimally with antibiotics, rheumatic fever can still occur in susceptible individuals. 1, 4 This highlights several critical points:

• At least one-third of rheumatic fever cases result from asymptomatic GAS infections, making primary prevention inherently challenging 1, 4
• Host susceptibility plays a major role, with genetic and immunologic factors determining who develops ARF after GAS infection 2
• Antibiotics must be started within 9 days of symptom onset to effectively prevent acute rheumatic fever 5

High-Risk Populations

Children and adolescents in the following circumstances face elevated risk: 6, 3

• Economically disadvantaged populations 6, 3
• Overcrowded living conditions (college dormitories, military barracks) 6, 3
• Areas with inadequate sanitation 3
• Parents of young children, teachers, healthcare workers 6
• Developing countries where ARF/RHD remains prevalent 3, 7

Secondary Prevention After Acute Rheumatic Fever

If acute rheumatic fever develops following scarlet fever or any GAS infection, continuous antimicrobial prophylaxis is mandatory to prevent recurrent attacks and progressive cardiac damage. 6, 1, 4

Prophylaxis Regimen

Benzathine penicillin G 1.2 million units intramuscularly every 4 weeks is the gold standard, providing approximately 10 times greater protection than oral antibiotics (0.1% vs 1% recurrence rate). 6, 8

• In high-risk populations or with recurrence despite adherence: Consider every 3-week administration 6, 4

Duration of Prophylaxis

The American Heart Association stratifies duration based on cardiac involvement: 6, 1, 4

• With carditis and residual heart disease: 10 years after last episode OR until age 40 (whichever is longer), sometimes lifelong 6, 1, 4
• With carditis but no residual heart disease: 10 years OR until age 21 (whichever is longer) 6, 1, 4
• Without carditis: 5 years OR until age 21 (whichever is longer) 6, 1, 4

Common Pitfalls to Avoid

• Never discontinue prophylaxis prematurely based solely on normal echocardiographic findings, as patients remain susceptible to recurrent GAS infection 8
• Don't assume that successful treatment of the initial scarlet fever eliminates risk—susceptible individuals can still develop ARF 1, 4
• Recognize that recurrent attacks cause progressively worse cardiac damage, making continuous (not episodic) prophylaxis essential 4
• Prophylaxis must continue even after valve surgery, including prosthetic valve replacement 6

Historical Context

While scarlet fever has become relatively benign with low mortality in developed countries over the past 150 years, recent sporadic outbreaks and resurgence of scarlet fever in some regions warrant renewed vigilance. 9, 3 The burden remains disproportionately high in developing countries where RHD continues as a major cause of cardiovascular morbidity and mortality. 7