ICD-10 Code L52 – Erythema nodosum (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L52 – Erythema nodosum
What it is
Erythema nodosum is an inflammatory skin condition that causes tender, red nodules, usually on the shins. It reflects an underlying reaction rather than a primary skin infection.
Clinical signs
You may see painful, raised nodules or plaques on the lower legs, often bilateral. Clinical features vary; refer to documentation for associated systemic findings or underlying triggers.
When to use this code
Use L52 when the provider documents erythema nodosum as the diagnosis, including cases described as panniculitis with characteristic tender nodules. It is appropriate when the condition is confirmed clinically and no more specific cause is being coded instead.
Apply this code for encounters focused on evaluating or managing the documented skin eruption. If the record identifies an underlying disease, code that condition as directed and confirm whether erythema nodosum is also reported.
Do not use for
Do not use L52 for nonspecific leg rash, cellulitis, or other nodular skin disorders without documentation of erythema nodosum. Check documentation if the note only states “painful bumps” or “panniculitis” without a clear diagnosis.
Coding tip
Code L52 only when the provider names erythema nodosum; otherwise, query for clarification before assigning it.