Algorithm for diagnosis of acute porphyria and use of hemin in patients with symptoms suggesting an acute porphyria attack

All symptomatic patients with suspected acute porphyria should have quantitative PBG, total porphyrins, and creatinine measured from the same spot urine sample. Urine creatinine is measured to allow normalization (results expressed per gram of creatinine). Because send-out results may not be reported for days to weeks, a rapid in-house qualitative or semi-quantitative method for documenting marked PBG elevation is extremely helpful, if available. Treatment can be initiated based on a positive result at the time of symptoms, and a negative result makes the diagnosis of an acute porphyria unlikely. However, qualitative results should be confirmed later on the same sample by quantitative methods. This screening approach is highly sensitive at the time of symptoms, and further testing should only be needed if the initial results are abnormal. Refer to UpToDate topics on acute porphyrias for further details of diagnosis and treatment and patterns of plasma and fecal porphyrin elevation.