A38.9 Scarlet fever, uncomplicated

Name of the Condition

• Scarlet fever, uncomplicated

Summary

Scarlet fever, uncomplicated is an infectious condition marked by a characteristic rash, fever, and sore throat. It is caused by Streptococcus pyogenes (group A streptococcus) bacteria that produce erythrogenic toxins, leading to systemic symptoms without additional complications. The condition typically follows streptococcal pharyngitis or skin infection and is most common in children.

Causes

Scarlet fever, uncomplicated is caused by infection with Streptococcus pyogenes bacteria that produce erythrogenic toxins. These toxins are responsible for the rash and other systemic symptoms. The bacteria 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, fever, and sore throat. A throat swab or rapid antigen test may confirm Streptococcus pyogenes infection. Laboratory tests, such as a complete blood count, may show elevated white blood cell counts. Imaging or other tests are not typically required unless complications are suspected.

Treatment Options

Treatment usually involves antibiotics, such as penicillin or amoxicillin, to eliminate the bacterial infection. Symptomatic relief may include fever reducers (e.g., acetaminophen) and throat lozenges. Rest and hydration are recommended to support recovery. Antibiotics also reduce the risk of transmission.

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. Complications are rare in uncomplicated cases but may occur if treatment is delayed.

Complications

While uncomplicated cases typically resolve without issues, potential complications include rheumatic fever, kidney inflammation (post-streptococcal glomerulonephritis), or ear infections. These are more likely if treatment is delayed or incomplete.

Lifestyle & Prevention

• Practice good hand hygiene to reduce transmission.
• Avoid close contact with infected individuals until they have completed at least 24 hours of antibiotic treatment.
• Cover the mouth and nose when coughing or sneezing.
• Stay home from school or work until fever and other symptoms improve.

When to Seek Professional Help

Seek medical attention if symptoms worsen, do not improve after 48 hours of antibiotic treatment, or if signs of complications (e.g., severe headache, difficulty breathing, or rash spreading rapidly) occur.

Tips for Medical Coders

Document the presence of uncomplicated scarlet fever, including clinical findings (e.g., rash, fever, sore throat) and absence of complications. Ensure the diagnosis aligns with the ICD-10-CM code A38.9, which is specific to uncomplicated cases. Verify that no additional codes for complications are required.