Postherpetic myelitis

This code describes inflammation of the spinal cord that occurs as a complication following a herpes zoster (shingles) infection. It represents a neurological sequela where the varicella-zoster virus, after reactivation, directly affects the spinal cord parenchyma, leading to neurological deficits.

Use this code when documentation explicitly states "postherpetic myelitis" or "myelitis due to herpes zoster" as a current condition. This typically occurs weeks to months after the initial shingles rash has resolved, and the patient presents with new or worsening neurological symptoms referable to the spinal cord.

• Ensure documentation clearly links the myelitis to a preceding herpes zoster infection.
• Do not confuse with acute myelitis (G04.9) or other forms of viral myelitis if the postherpetic etiology is not specified.
• Consider sequencing this code as a primary diagnosis if it is the reason for the encounter, followed by codes for any associated neurological deficits.