Diagnosing acute intermittent porphyria (AIP)

Diagnosis of AIP is challenging because signs and symptoms mimic other, more common conditions.1 AIP is a rare inherited disease caused by a partial deficiency of the enzyme porphobilinogen (PBG) deaminase in the heme biosynthetic pathway.1

Accuracy and speed

are critical in the diagnosis of an acute porphyric attack.1

Interactive diagnostic algorithm for AIP

PATIENT PRESENTATION

PATIENT HISTORY

INDEX OF SUSPICION

ACTION

Select the checkbox for each symptom your patient presents with and confirm existing family history.
If a selection has been made, a text box will appear to enter any additional information.
NOTE: Your responses will not be collected or stored.

  • Present in >85% of patients
  • Neuropathic in origin
  • Usually severe, unremitting, and diffuse
Other common acute symptoms†1

  • Gastrointestinal

  • Urinary

  • Neurologic

  • Cardiovascular

† Not all symptoms in porphyric patients are due to porphyria – porphyric patients are not immune to other conditions.2

‡ In approximately one third of cases, family history is absent likely due to disease latency or lack of diagnosis.2

Enter your patient’s gender and age. Use the checkboxes to indicate whether they identify with any of the risk factors listed below. If a selection has been made, a text box will appear to enter any additional information.

Patient characteristics, including:

  • Gender (acute attacks are 4 to 5 times more common in women)2
  • Age of patient (acute attacks most common in their 30s)2

and/or possible precipitating factors, including:

NOTE: This list does not include all precipitating factors for AIP.

Please review your Patient Presentation and Patient History selections before proceeding.

Patient Presentation

Patient History

PBG urine test

  • Screening tests to measure the levels of the porphyrin precursor PBG in urine are essential to confirm a diagnosis of acute porphyria3-5
  • Acute attacks are accompanied by increased production and excretion of PBG in AIP3-5
  • It is essential that before arranging for a PBG urine test, the physician consult with the laboratory to ensure that the test is available and also know the recommended procedures as to how and when to collect the urine sample4

Genetic testing

  • AIP is a metabolic disorder3,4,6
  • For confirmatory molecular genetic testing, physicians should consult their provincial laboratory services for more information3

PRINT OR SAVE COMPLETED PDF FOR PATIENT RECORD

NOTE: Your responses will not be collected or stored.

Diagnosing AIP / Diagnostic Testing / Family Testing / Differential Diagnosis / Interactive Diagnostic Algorithm

References:

  1. Anderson KE, Bloomer JR, Bonkovsky HL, et al. Recommendations for the Diagnosis and Treatment of the Acute Porphyrias. Ann Intern Med 2005;142:439‑450.
  2. Thadani H, Deacon A, Peters T. Diagnosis and management of porphyria. BMJ. 2000;320(7250);1647-1651.
  3. National Organization for Rare Disorders. Rare disease Database: Acute Intermittent Porphyria. Accessed April 2026 at https://rarediseases.org/rare-diseases/acute-intermittent-porphyria/
  4. Canadian Association for Porphyria. Understanding Porphyria. Accessed April 2026 at https://www.porphyriacanada.ca/understanding-porphyria/
  5. Moghe A, Dickey A, Erwin A, Leaf RK, O'Brien A, Quigley JG, Thapar M, Anderson KE. Acute hepatic porphyrias: Recommendations for diagnosis and management with real-world examples. Mol Genet Metab. 2023 Nov;140(3):107670.
  6. Anderson KE, Lobo R, Salazar D, Schloetter M, Spitzer G, White AL, Young RM, Bonkovsky HL, Frank EL, Mora J, Tortorelli S. Biochemical Diagnosis of Acute Hepatic Porphyria: Updated Expert Recommendations for Primary Care Physicians. Am J Med Sci. 2021 Aug;362(2):113-121.

Diagnosing acute intermittent porphyria (AIP)

First Name:
Last Name:
Date of Birth:

PATIENT PRESENTATION

PATIENT HISTORY

ACTION

PBG urine test

  • Screening tests to measure the levels of the porphyrin precursor PBG in urine are essential to confirm a diagnosis of acute porphyria1-3
  • Acute attacks are accompanied by increased production and excretion of PBG in AIP1-3
  • It is essential that before arranging for a PBG urine test, the physician consult with the laboratory to ensure that the test is available and also know the recommended procedures as to how and when to collect the urine sample2

Genetic testing

  • AIP is a metabolic disorder1,2,4
  • For confirmatory molecular genetic testing, physicians should consult their provincial laboratory services for more information1
  1. National Organization for Rare Disorders. Rare disease Database: Acute Intermittent Porphyria. Accessed April 2026 at https://rarediseases.org/rare-diseases/acute-intermittent-porphyria/
  2. Canadian Association for Porphyria. Understanding Porphyria. Accessed April 2026 at https://www.porphyriacanada.ca/understanding-porphyria/
  3. Moghe A, Dickey A, Erwin A, Leaf RK, O'Brien A, Quigley JG, Thapar M, Anderson KE. Acute hepatic porphyrias: Recommendations for diagnosis and management with real-world examples. Mol Genet Metab. 2023 Nov;140(3):107670.
  4. Anderson KE, Lobo R, Salazar D, Schloetter M, Spitzer G, White AL, Young RM, Bonkovsky HL, Frank EL, Mora J, Tortorelli S. Biochemical Diagnosis of Acute Hepatic Porphyria: Updated Expert Recommendations for Primary Care Physicians. Am J Med Sci. 2021 Aug;362(2):113-121.
Downloaded from DiagnosingAIP.ca