I01

I01 is a designation used in the ICD-10-CM medical coding system to classify a specific presentation of rheumatic fever involving the heart. It sits within the rheumatic fever category in the I00–I02 block and is used in clinical documentation, billing, and epidemiological reporting. Subcodes under I01 provide more detail about the exact cardiac involvement or clinical features, as required by coding guidelines.

Rheumatic fever is an inflammatory condition that can occur after an infection with group A Streptococcus bacteria, such as untreated strep throat. When the heart is involved, rheumatic fever can affect the endocardium, myocardium, and pericardium, potentially leading to rheumatic heart disease over time. Other common manifestations include migratory arthritis, chorea, subcutaneous nodules, and skin rashes, though the heart involvement is the aspect highlighted by I01.

Diagnosis typically relies on clinical criteria (historical and current symptoms), evidence of preceding streptococcal infection, and imaging studies such as echocardiography to assess cardiac involvement. The Jones criteria are often referenced in establishing a diagnosis, with laboratory tests confirming prior infection.

Treatment focuses on eradicating the streptococcal bacteria, controlling inflammation, and preventing recurrence. Standard therapy includes appropriate antibiotics (commonly penicillin) and anti-inflammatory treatment (such as aspirin or NSAIDs); in some cases, corticosteroids or other interventions may be used. Long-term secondary prevention with regular antibiotic prophylaxis is important to reduce the risk of relapse and further cardiac damage.

See also: rheumatic fever, rheumatic heart disease, ICD-10-CM codes I00–I02.