E80.21
BillableAcute intermittent (hepatic) porphyria
HCC Category Mapping
V28HCC 50 — Glycogen/Amino-Acid/Other Metabolic Disorders
0.289V24HCC 23 — Other Significant Endocrine and Metabolic Disorders
0.230ESRDHCC 23 — Other Significant Endocrine and Metabolic Disorders
0.000RxHCCHCC 43 — Other Significant Endocrine and Metabolic Disorders
0.000What This Code Means
A severe inherited porphyria causing sudden attacks of severe abdominal pain, neurological symptoms, and psychiatric manifestations.
Coding Tips
- •Document acute attack episodes separately from the chronic condition
- •Code associated neurological or psychiatric complications that occur during attacks
Clinical Significance
Acute intermittent porphyria (AIP) is the most common acute hepatic porphyria, caused by deficiency of porphobilinogen deaminase (HMBS). It presents with neurovisceral crises including severe abdominal pain, neuropsychiatric symptoms, autonomic dysfunction, and potentially life-threatening hyponatremia, typically triggered by drugs, hormones, fasting, or stress.
Documentation Requirements
- ✓Provider diagnosis of acute intermittent porphyria
- ✓Elevated urine porphobilinogen (PBG) and aminolevulinic acid (ALA) during acute attacks
- ✓HMBS/PBGD enzyme activity or HMBS gene mutation testing
- ✓Attack history: frequency, triggers (medications, hormones, fasting), severity
- ✓List of safe vs. unsafe medications maintained in the record
- ✓Acute management: IV hemin (Panhematin), glucose loading, pain management
- ✓Current preventive measures (GnRH agonist for menstrual-triggered attacks)
Commonly Confused Codes
E80.1 — Porphyria cutanea tarda: cutaneous porphyria without acute neurovisceral attacksE80.29 — Other porphyria: includes variegate porphyria and hereditary coproporphyria which can also cause acute attacks but have skin involvement tooE80.20 — Unspecified porphyria: avoid when AIP is specifically diagnosedR10.9 — Unspecified abdominal pain: AIP attacks may be misdiagnosed as surgical abdomen
Code Hierarchy
└E80Disorders of porphyrin and bilirubin metabolism└E80.2Other and unspecified porphyria└E80.21Acute intermittent (hepatic) porphyria
└E80.21Acute intermittent (hepatic) porphyria