E09.41

HCC Category Mapping

What This Code Means

Diabetes caused by medications or chemicals that damages a single nerve, causing weakness or numbness in one area of the body.

Coding Tips

• •Identify the specific drug or chemical causing the diabetes and document it in the medical record
• •Confirm the mononeuropathy affects only one nerve; if multiple nerves are involved, use E09.42 instead

Clinical Significance

Drug or chemical induced diabetes mellitus with diabetic mononeuropathy represents damage to a single peripheral nerve or nerve group caused by drug-induced diabetes. Unlike the more common diffuse polyneuropathy, mononeuropathy causes focal deficits such as wrist drop, foot drop, or cranial nerve palsies (e.g., third nerve palsy causing double vision). The acute onset and focal nature often prompt urgent neurological evaluation to rule out other causes.

Documentation Requirements

• ✓The causative drug or chemical must be identified and coded.
• ✓The specific nerve affected should be documented (e.g., median, ulnar, peroneal, or cranial nerve).
• ✓Clinical findings including motor and sensory deficits in the affected nerve distribution must be described.
• ✓Electrodiagnostic studies (nerve conduction/EMG) confirming the diagnosis should be referenced when available.

Commonly Confused Codes