ICD-10 Code for Temporal Arteritis
The ICD-10 code for temporal arteritis (giant cell arteritis) is M31.6.
Understanding the Terminology
Temporal arteritis and giant cell arteritis (GCA) are synonymous terms referring to the same condition—a systemic vasculitis affecting large and medium-sized vessels, particularly the cranial arteries derived from the carotid artery 1. The condition is also documented in medical literature and classification systems under both names interchangeably 2, 3, 4.
Clinical Context for Proper Coding
When using this ICD-10 code, it's important to understand that:
Age requirement: GCA virtually never occurs in adults younger than 50 years of age 4, which is now an absolute requirement in the 2022 ACR/EULAR classification criteria 5
Disease manifestations: The code M31.6 encompasses both:
- Cranial GCA (classic temporal arteritis with headache, scalp tenderness, jaw claudication)
- Large vessel GCA (aortic and great vessel involvement) 1
Common Documentation Pitfalls
When coding for temporal arteritis, ensure proper documentation includes:
- Confirmation method (temporal artery biopsy showing histopathological features of temporal arteritis, or imaging findings such as the "halo sign" on ultrasound) 1
- Elevated inflammatory markers (ESR ≥50 mm/hour or CRP ≥10 mg/liter are present in >95% of cases at diagnosis) 1
- Clinical manifestations that support the diagnosis
The code M31.6 should be used regardless of whether the diagnosis was confirmed by biopsy or imaging, as both are accepted diagnostic modalities 1.