Differentials

Other conditions that cause abdominal pain

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

AIP symptoms are neurologic rather than inflammatory, so peritoneal signs, fever, and leukocytosis are usually not as prominent as in other abdominal conditions.

INVESTIGATIONS

CBC to eliminate leukocytosis.

Substantial increase of urinary porphobilinogen confirms porphyria.

Delta-aminolevulinate dehydratase deficiency porphyria

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Symptoms similar to AIP but extremely rare condition.[21]

INVESTIGATIONS

Delta-aminolevulinic acid and coproporphyrin III are markedly increased in urine, and porphobilinogen is normal or slightly increased. Erythrocyte zinc protoporphyrin is also markedly increased.

Hereditary coproporphyria

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Presentation the same as AIP, but occasionally associated with blistering skin lesions.

INVESTIGATIONS

Fecal total porphyrins are substantially increased with a marked, usually isolated increase in fecal coproporphyrin III by high-performance liquid chromatography.[18]

Variegate porphyria

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

May present as in AIP but often associated with blistering skin lesions.

INVESTIGATIONS

Increased plasma porphyrin with a diagnostic fluorescence maximum at neutral pH.

Fecal porphyrins are substantially increased with a predominance of coproporphyrin III and protoporphyrin by high-performance liquid chromatography.[22][23]

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