- Hereditary enzymatic disorders of haem production that result in the accumulation of intermediate haem metabolites (porphyrins)
- Neurotoxic in high concentrations.
- Acute intermittent porphyria (AIP) is the commonest porphyria causing abdominal pain
- Presentation
- Typically presents with severe generalized abdominal pain, thought to be neural in origin.
- Other gastrointestinal symptoms include nausea, vomiting and ileus, and these may be accompanied by acute peripheral motor neuropathy.
- Acute attacks are triggered by stress, caloric restriction and changes to medications or hormonal levels and may be preceded by neuropyschological symptoms including fatigue and poor concentration.
- Clinical
- Urine, which may develop a red/purple colour
- Diagnosis
- Urine can be tested for elevated levels of porphobilinogen and porphyrins at the time of an acute attack to establish the diagnosis.
- Management
- Attacks are managed with intravenous hemin, which limits porphyrin synthesis
- Supportive care includes intravenous fluids, analgesia, anti-emetics and anti-convulsants if required
- Monitoring for rare neurotoxic effects including paralysis, seizures and respiratory failure.
- Referral to a haematologist or porphyria specialist is advised for prevention of future attacks, genetic counselling and monitoring of long-term complications such as motor neuropathy.