Clinical features (neurological porphyrias):

General features:

  • Acute ascending paralysis with areflexia, affecting VII nerve as well
  • Sensory loss may occur “swimming trunk distribution”
  • Autonomic neuropathy: tachycardia and orthostatic hypotension
  • Confusion, anxiety
  • Urine becomes dark on exposure to sunlight.


  • Acute forms: Cause neurological disease and raised ALA
  • Acute intermittent porphyria AIP: no cutaneous rash
  • Variegate porphyria
  • Hereditary coproporphyria: extremely rare
  • Non-Acute forms: no neurological disease
  • Porphyria cutanea tarda PCT
  • Cutaneous hepatic porphyria
  • Congenital porphyria
  • Erythropoietic protoporphyria EPP


Acute intermittent porphyria AIP:

Screen: 24 hr urinary collection for porphyrin levels
Aminolevulinic acid ALA: high
Porphobilinogen PBG: high


RBC enzymes:
Porphobilinogen PBG deaminase: reduced
Delta ALA synthetase: high
Causes neurological symptoms. Note differential diagnosis: Lead poisoning


For crisis: hematin I.V.
Prevention of attacks

Variegate porphyria (South African):

Causes neurological symptoms

Porphyria cutanea tarda PCT:

Urine uroporphyrin I (URO I): high
Stool isocoproporphyrin (ISOCOPRO): high
Does not causes neurological symptoms

Erythropoietic protoporphyria EPP:

Screen: erythrocyte porphyrins
Protoporphyrinogen IX (PROTO IX)
Does not causes neurological symptoms

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