Acute Intermittent Porphyria
Also written as AIP.
Abdominal pain, constipation, neuropsychiatric symptoms and weakness precipitated by drugs is acute intermittent porphyria, and urine porphobilinogen and porphyrins make the diagnosis.
What our notes say
- Abdominal pain, constipation, neuropsychiatric symptoms and weakness precipitated by drugs is acute intermittent porphyria, and urine porphobilinogen and porphyrins make the diagnosis. (Psychiatry Year 6 CAT: June 2023, psychopathology, psychosis, mood and child psy)
- What is the most likely diagnosis and a critical management strategy for an acute attack? → Acute intermittent porphyria (AIP), and management involves IV haem arginate and high carbohydrate loading. (Endocrine & Renal Pathology)
- Acute intermittent porphyria, precipitated by the drugs. (Psychiatry Year 6 CAT: October 2023, violence, defence mechanisms, hallucination)
- Porphyria: disturbed porphyrin metabolism; 5 types (congenital erythropoietic, erythrohepatic protoporphyria, acute intermittent, porphyria cutanea tarda, mixed); photosensitive subepidermal vesicles with vessel wall thickening (Exam Prep: Skin Infections, Psoriasis & Pemphigus)
- (c) Discuss the laboratory diagnosis of Acute Intermittent Porphyria. (4 marks) (Chemical Pathology Practice Examination)
- Acute Intermittent Porphyria (AIP) - Most Common Acute Porphyria: (Chemical Pathology Practice Examination)
Study material on Acute Intermittent Porphyria
- Chemical Pathology MCQs: Clinical Chemistry, Endocrine & Renal
- Chemical Pathology Practice Examination
- bchem EOY 2011
- bchem EOY 2011 (2)
- Endocrine & Renal Pathology
- Chemical Path Mcqs
- Year 3: Endocrine and Metabolic Pathology — Part 2
- CHEMICAL PATHOLOGY MCQs
- Endocrine & Renal Pathology
- Endocrine & Renal Pathology
- Chemical Pathology
Practice questions on Acute Intermittent Porphyria
The enzyme deficient in acute intermittent porphyria is
- Uroporphyrinogen III synthase
- Ferrochelatase
- Porphobilinogen deaminase
- ALA dehydratase
Answer: C. PBG deaminase (hydroxymethylbilane synthase) deficiency causes PBG and ALA accumulation, triggering neurovisceral attacks. ---
Acute intermittent porphyria (AIP) is caused by deficiency of porphobilinogen deaminase. The classic triad is
- Photosensitive blistering skin rash, hepatosplenomegaly, anemia
- Abdominal pain, neuropsychiatric symptoms, and dark urine (no skin rash)
- Hemolytic anemia, jaundice, and splenomegaly
- Peripheral neuropathy, renal failure, and hypertension
Answer: B. AIP: autosomal dominant, porphyrin precursors (ALA, PBG) accumulate in urine. Classic triad: severe colicky abdominal pain + neuropsychiatric features (psychosis, neuropathy) + dark/port-wine urine. NO photosensitivity (unlike porphyria cutanea tarda). Precipitated by: alcohol, drugs (OCP, barbiturates, sulfonamides), fasting, infection. Treatment: IV hemin + glucose loading + avoid triggers. ---
Acute intermittent porphyria (AIP) presents with the classic triad of
- Blistering photosensitive rash, hepatosplenomegaly, and hemolytic anemia
- Abdominal pain, neuropsychiatric symptoms, and dark urine — WITHOUT skin involvement
- Peripheral neuropathy, renal failure, and hypertension
- Photosensitivity, skin fragility, and hypertrichosis
Answer: B. AIP: porphobilinogen deaminase deficiency → ALA and PBG accumulate. No photosensitivity (porphyrins don't accumulate in skin). Precipitants: alcohol, OCP, barbiturates, sulfonamides, fasting, infection. Urine turns dark/port-wine on standing. Diagnosis: elevated urine PBG during attack. Treatment: IV hemin (heme arginate) + IV glucose (suppresses ALA synthase) + avoid triggers.
The enzyme deficient in acute intermittent porphyria (AIP) is ---
- Uroporphyrinogen III synthase
- Ferrochelatase
- Porphobilinogen deaminase
- ALA dehydratase
Answer: C.
Which of the following statements is FALSE regarding acute intermittent porphyria ---
- Originates in the liver and is autosomal dominant
- Is caused by a deficiency in porphobilinogen deaminase, which is involved in the conversion of porphobilinogen (PBG) to uroporphyrinogen…
- Results in accumulation of PBG, uroprophryin, and 5-ALA in the plasma and the urine
- Patients have neuropsychiatric symptoms and abdominal pain (neurovisceral)
- Patients are photosensitive (cutaneous photosensitivity)
Answer: A.