ICD-10 Guide

A43.9

Scarlet fever, unspecified

BILLABLE STATUSYes

IMPLEMENTATION DATEOctober 1, 2015

LAST UPDATED09/05/2025

Code Description

ICD-10 A43.9 is a billable code used to indicate a diagnosis of scarlet fever, unspecified.

Key Diagnostic Point:

Scarlet fever is an infectious disease caused by group A Streptococcus (Streptococcus pyogenes), characterized by a distinctive red rash, fever, and sore throat. The rash typically appears 12 to 48 hours after the onset of fever and is often described as feeling like sandpaper. Scarlet fever primarily affects children aged 5 to 15 years but can occur in adults as well. The condition is often associated with streptococcal pharyngitis and can lead to complications such as rheumatic fever or post-streptococcal glomerulonephritis if left untreated. In immunocompromised patients, the presentation may be atypical, and the risk of severe complications increases. Diagnostic challenges arise due to overlapping symptoms with other conditions, such as viral exanthems or other bacterial infections. Accurate diagnosis often requires throat culture or rapid antigen detection tests to confirm the presence of group A Streptococcus. Treatment typically involves antibiotics, which can reduce the duration of symptoms and prevent complications. However, in immunocompromised patients, the management may require a more aggressive approach due to the increased risk of opportunistic infections and atypical presentations.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

Variability in clinical presentation, especially in immunocompromised patients.
Need for laboratory confirmation to differentiate from other conditions.
Potential for complications that may require additional coding.
Documentation of patient history and risk factors is crucial for accurate coding.

Audit Risk Factors

Inadequate documentation of clinical findings.
Failure to confirm diagnosis with laboratory tests.
Misclassification of the condition as a viral infection.
Lack of documentation regarding patient history and immunocompromised status.

Specialty Focus

Medical Specialties

Pediatrics

Documentation Requirements

Thorough documentation of symptoms, laboratory results, and treatment plans.

Common Clinical Scenarios

Children presenting with fever, sore throat, and rash.

Billing Considerations

Consideration of age and vaccination status in the differential diagnosis.

Infectious Disease

Documentation Requirements

Detailed history of immunocompromised status and any prior infections.

Common Clinical Scenarios

Immunocompromised patients presenting with atypical symptoms.

Billing Considerations

Need for comprehensive management plans due to increased risk of complications.

Coding Guidelines

Inclusion Criteria

Use A43.9 When

Follow the official ICD
CM coding guidelines, ensuring that the diagnosis is supported by clinical documentation and laboratory results

Exclusion Criteria

Do NOT use A43.9 When

Exclude conditions that are not directly related to scarlet fever

Related CPT Codes

87070CPT Code

Culture, bacterial, any source

Clinical Scenario

Used when confirming the diagnosis of scarlet fever.

Documentation Requirements

Document the site of culture and results.

Specialty Considerations

Pediatricians should ensure proper specimen collection techniques.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of scarlet fever, improving the ability to capture clinical nuances and complications associated with the disease.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of scarlet fever, improving the ability to capture clinical nuances and complications associated with the disease.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of scarlet fever, improving the ability to capture clinical nuances and complications associated with the disease.

Resources

Clinical References

•
CDC Scarlet Fever Information

Coding & Billing References

•
CDC Scarlet Fever Information

Frequently Asked Questions

What are the common symptoms of scarlet fever?

Common symptoms include a red rash, fever, sore throat, and a 'strawberry tongue.'

How is scarlet fever diagnosed?

Diagnosis is typically made based on clinical presentation and confirmed with a throat culture or rapid antigen test.

What is the treatment for scarlet fever?

Treatment usually involves antibiotics, such as penicillin, to eliminate the infection and prevent complications.

ICD-10 A43.9 is a billable code used to indicate a diagnosis of scarlet fever, unspecified.