The acute porphyrias.

The various types of acute porphyria are discussed, as well as their mode of inheritance and the enzyme deficiencies responsible for the symptoms. The symptoms and signs of an acute attack are then described, especially those due to neuropathies and to disturbances of behaviour. Agents which can precipitate attacks are listed. These are most frequently drugs, and as they include those used for anti-epileptic treatment problems soon arise as seizures often occur in this condition. The main complications are hypertension and renal failure, and examples of hyponatraemia and folate deficiency are illustrated. The urgency to diagnose this disorder lies in the need to avoid precipitating factors. Screening tests are discussed, and those needed to confirm the diagnosis. The prognosis has improved over the years, due to increased awareness of the disorder, and better management. During an acute attack the treatment of pain and vomiting will be of particular importance, and then haematin or chelating agents can be tried. With better management most of those who have inherited acute porphyria should be able to lead a normal life.