Causalgia of left lower limb

This code represents a rare, severe, burning pain syndrome affecting the left lower extremity, often accompanied by vasomotor and sudomotor dysfunction, trophic changes, and allodynia or hyperalgesia. It is a form of complex regional pain syndrome (CRPS) type II, specifically resulting from a confirmed nerve injury.

Use this code when documentation clearly indicates a diagnosis of causalgia (CRPS type II) localized to the left lower limb, following a specific, identifiable nerve injury. Supporting documentation should detail the nerve injury and the characteristic symptoms of causalgia in the affected limb.

• Ensure documentation differentiates between CRPS type I (reflex sympathetic dystrophy) and CRPS type II (causalgia) based on the presence of a confirmed nerve injury.
• Verify laterality; this code is specific to the left lower limb.
• Do not use this code for unspecified CRPS or CRPS type I; use the appropriate G90.5- series codes for those conditions.