acute intermittent porphyria (redirected from Porphyria, acute intermittent)

porphyria /por·phy·ria/ (por-fēr´e-ah) any of a group of disturbances of porphyrin metabolism characterized by increase in formation and excretion of porphyrins or their precursors.

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acute intermittent porphyria  (AIP) hereditary hepatic porphyria due to a defect of pyrrole metabolism, with recurrent attacks of abdominal pain, gastrointestinal and neurologic disturbances, and excessive amounts of δ-aminolevulinic acid and porphobilinogen in the urine.

congenital erythropoietic porphyria  (CEP) a form of erythropoietic porphyria, with cutaneous photosensitivity leading to mutilating lesions, hemolytic anemia, splenomegaly, excessive urinary excretion of uroporphyrin and coproporphyrin, and invariably erythrodontia and hypertrichosis.

porphyria cuta´nea tar´da  (PCT) a form characterized by cutaneous sensitivity that causes scarring bullae, hyperpigmentation, facial hypertrichosis, and sometimes sclerodermatous thickenings and alopecia; it is associated with reduced activity of an enzyme of heme synthesis.

erythropoietic porphyria  that in which excessive formation of porphyrin or its precursors occurs in bone marrow normoblasts, including congenital erythropoietic porphyria and erythropoietic protoporphyria.

hepatic porphyria  that in which the excess formation of porphyrin or its precursors occurs in the liver.

hepatoerythropoietic porphyria  (HEP) a severe form of porphyria cutanea tarda believed to result from a lack of activity of the enzyme catalyzing the conversion of uroporphyrinogen to coproporphyrinogen in the biosynthesis of heme.

variegate porphyria  (VP) a hereditary hepatic porphyria, with chronic skin manifestations, chiefly extreme mechanical fragility of the skin, mainly of areas exposed to sunlight, episodes of abdominal pain, neuropathy, and typically an excess of coproporphyrin and protoporphyrin in bile and feces.

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acute intermittent porphyria

n.

See intermittent acute porphyria.

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Acute intermittent porphyria

An inherited disease affecting the liver and bone marrow. The liver overproduces a specific acid and the disease is characterized by attacks of high blood pressure, abdominal colic, psychosis, and nervous system disorders.

Mentioned in: Thyroid Function Tests

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acute intermittent porphyria (AIP),

an autosomal-dominant, genetically transmitted metabolic hepatic disorder characterized by acute attacks of neurologic dysfunction that can be started by environmental or endogenous factors. Women are affected more frequently than men, and attacks often are precipitated by starvation or severe dieting, alcohol ingestion, bacterial or viral infections, and a wide range of pharmaceutic products. Any part of the nervous system can be affected, and an initial common effect is mild to severe abdominal pain. Other effects can include tachycardia, hypertension, hyponatremia, peripheral neuropathy, and organic brain dysfunction marked by seizures, coma, hallucinations, and respiratory paralysis. A frequent diagnostic factor is a high level of porphyrin precursors in the urine, which usually increases during periods of acute attacks. Treatment is generally symptomatic, with emphasis on respiratory support, beta-blockers, and pain control. Education of the patient focuses on environmental factors, particularly medications such as barbiturates, that are known to cause an onset of symptoms, as well as avoidance of alcohol, sunlight, and skin trauma. A high-carbohydrate diet is reported to reduce the risk of acute attacks because glucose tends to block the induction of hepatic gamma-aminolevulinic acid synthetase, an enzyme involved in the porphyrias. See also porphyria.

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acute intermittent porphyria

Hematology An AD condition caused by a deficiency of porphobilinogen deaminase, resulting in overproduction of δ-aminolevulinic acid Clinical Recurrent abdominal colic, constipation, fever, leukocytosis, postural hypotension, peripheral neuritis, polyneuropathy, paraplegia, urinary retention, respiratory paralysis, behavioral changes and episodic organic psychosis, photosensitivity; worse with barbiturates Lab ↑ δ-aminolevulinic acid, urine porphobilinogen