ICD-10 Code L04.1 – Acute lymphadenitis of trunk (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L04.1 – Acute lymphadenitis of trunk
What it is
L04.1 identifies an acute inflammation of lymph nodes in the trunk, such as axillary, inguinal, or other trunk-region nodes. Use it when the record specifically describes acute lymphadenitis in this area.
Clinical signs
Typical findings include tender, enlarged lymph nodes with localized swelling and possible warmth or redness. Clinical features vary; refer to documentation for the exact node location and whether the process is acute.
When to use this code
Use this code when the provider documents acute lymphadenitis affecting lymph nodes of the trunk and does not specify a more precise site code. It fits encounters where the diagnosis is clearly inflammatory and limited to trunk-region nodes. If the note names an underlying infection or another primary condition, code that condition as directed by the documentation.
Do not use for
Do not use L04.1 for chronic lymph node enlargement, generalized lymphadenopathy, or lymphadenitis outside the trunk. Check documentation if the record only says “lymph node swelling” without confirming an acute inflammatory process.
Coding tip
Capture the exact lymph node location and acute status from the provider note before assigning L04.1.