Q: How do you diagnose acute porphyria?

A. Any patient presenting with unexplained abdominal pain, mental dysfunction or peripheral neuropathy should be suspected to have acute porphyria. A clue to the diagnosis is dark reddish brown color of the urine during an attack, which becomes more pronounced if it is left standing. A simple urine test can be done to test for presence of porphobilinogen in the urine. Either 200ml of 24-hour urine is tested (with no added preservative) or spot sample of at least 100ml urine can be tested.

Test :


Equal volumes of urine and Ehrlich's reagent are mixed in a tube. If solution becomes pink, it indicates either the presence of porphobilinogen or urobilinogen. The presence of porphobilinogen can be confirmed by the addition of about two volumes of chloroform to the solution and completely shaking it. The mixture is allowed to stand. If pink color remains in the upper aqueous layer, it shows the presence of porphobilinogen. If it moves to the lower layer, it denotes the presence of urobilinogen.