Postherpetic trigeminal neuralgia

This code signifies a chronic neuropathic pain condition affecting the trigeminal nerve, occurring as a sequela of herpes zoster (shingles) infection. The pain is typically severe, lancinating, and persistent, localized to one or more branches of the trigeminal nerve distribution (e.g., ophthalmic, maxillary, mandibular). It develops or persists for at least three months after the acute rash has resolved.

Use this code when documentation clearly indicates persistent or recurrent trigeminal neuralgia that developed following a herpes zoster infection. The patient's history should confirm a prior shingles outbreak affecting the dermatome supplied by the trigeminal nerve. This diagnosis is typically made after other causes of trigeminal neuralgia have been ruled out.

• Ensure documentation explicitly links the trigeminal neuralgia to a prior herpes zoster infection.
• Do not confuse with acute zosteriform trigeminal neuralgia (during the active rash phase) or trigeminal neuralgia from other etiologies.
• Consider co-reporting with codes for pain severity or specific nerve involvement if further detail is documented.