ICD-10 Code L03.124 – Acute lymphangitis of left upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L03.124 – Acute lymphangitis of left upper limb
What it is
Use this code for an acute inflammation or infection of the lymphatic vessels in the left arm. It describes a localized soft tissue infection affecting the left upper limb.
Clinical signs
Typical findings include redness, warmth, swelling, and tender linear streaking tracking along lymphatic channels. Regional lymph node tenderness may be present; clinical features vary, so refer to documentation.
When to use this code
Assign L03.124 when the provider documents acute lymphangitis specifically involving the left upper limb. Use it for notes describing spreading erythema or lymphatic streaking in the left arm, with or without an identified source of infection.
If documentation only states cellulitis, abscess, or nonspecific arm infection, check the record before coding this diagnosis.
Do not use for
Do not use this code for lymphangitis in another body site or for chronic lymphatic disorders. It is also not appropriate when the record supports cellulitis alone without lymphangitic involvement.
Coding tip
Verify laterality and the word “acute” in the provider note before assigning L03.124.