A38 Scarlet fever

Name of the Condition

• Scarlet fever

Summary

Scarlet fever is an infectious disease characterized by a distinctive rash, fever, and sore throat. It is caused by certain strains of Streptococcus pyogenes (group A streptococcus) and typically follows a streptococcal pharyngitis or skin infection. The condition is most common in children and is marked by a bright red rash that feels like sandpaper, often accompanied by a strawberry tongue and flushed cheeks.

Causes

Scarlet fever is caused by infection with Streptococcus pyogenes bacteria that produce erythrogenic toxins. These toxins are responsible for the characteristic rash and other systemic symptoms. The bacteria are spread through respiratory droplets or direct contact with infected individuals or contaminated surfaces.

Risk Factors

• Close contact with someone who has streptococcal infection
• Age (most common in children aged 5–15 years)
• Crowded environments (e.g., schools, daycare)
• Recent history of streptococcal pharyngitis or skin infection

Symptoms

• Sudden onset of fever and sore throat
• Bright red rash with a sandpaper-like texture, typically starting on the chest and spreading to the trunk and extremities
• Strawberry tongue (swollen, red tongue with visible papillae)
• Flushed face with circumoral pallor (pale area around the mouth)
• Headache and body aches
• Nausea or vomiting (less common)

Diagnosis

Diagnosis is based on clinical presentation, including the characteristic rash, sore throat, and strawberry tongue. Laboratory confirmation may involve a throat swab to identify Streptococcus pyogenes via culture or rapid antigen detection test. Blood tests are not typically required for routine diagnosis.

Treatment Options

• Antibiotics: Penicillin or amoxicillin are first-line treatments to eliminate the bacteria and prevent complications.
• Symptomatic relief: Pain relievers (e.g., acetaminophen or ibuprofen) for fever and sore throat.
• Hydration: Encouraging fluid intake to prevent dehydration.
• Rest: Adequate rest to support recovery.

Prognosis and Follow-Up

With prompt antibiotic treatment, most individuals recover fully within a week. Follow-up may include a repeat throat swab to confirm eradication of the bacteria, especially in cases of recurrent infection or outbreaks. Untreated cases can lead to complications such as rheumatic fever or kidney inflammation.

Complications

• Rheumatic fever (affecting the heart, joints, and other tissues)
• Post-streptococcal glomerulonephritis (kidney inflammation)
• Otitis media (middle ear infection)
• Pneumonia or sinusitis (secondary bacterial infections)

Lifestyle & Prevention

• Practice good hand hygiene, especially after coughing or sneezing.
• Avoid sharing utensils, towels, or other personal items with infected individuals.
• Stay home from school or work until 24 hours after starting antibiotics to prevent spread.
• Ensure proper wound care to reduce skin infection risk.

When to Seek Professional Help

Seek medical attention if symptoms worsen or persist despite treatment, or if signs of complications (e.g., severe headache, difficulty breathing, or swollen joints) develop. Immediate care is recommended for high fever, severe sore throat, or rash spreading rapidly.

Tips for Medical Coders

Document the presence of the characteristic rash, sore throat, and any associated symptoms (e.g., strawberry tongue) to support the diagnosis. Ensure the code A38 is used for confirmed cases of scarlet fever, and note any complications or underlying streptococcal infection if present.