Acute intermittent porphyria: enzyme deficiency (HMBS/PBG deaminase)

The 5 Ps of acute intermittent porphyria: Pain (severe abdominal pain, usually the presenting feature); Polyneuropathy (motor-predominant peripheral neuropathy, which can progress to respiratory paralysis); Psychiatric symptoms (anxiety, agitation, confusion, occasionally hallucinationsSeeing, hearing, or otherwise sensing things that are not really there.Read more →); Precipitated (by cytochrome P450A family of liver enzymes that break down most drugs, and a common site of drug interactions.Read more →-inducing drugs, fasting, alcohol, infection or hormonal change); Port-wine urine (darkens on standing as porphobilinogen and porphyrins oxidise on exposure to light and air). Say all five out loud without hesitating and you can reconstruct the whole clinical picture from scratch.