porphyria cutanea tarda

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Related to porphyria cutanea tarda: acute intermittent porphyria


a genetic disorder characterized by a disturbance in porphyrin metabolism with resultant increase in the formation and excretion of porphyrins (uroporphyrin and coproporphyrin) or their precursors; called also hematoporphyria. Porphyrins, in combination with iron, form hemes, which in turn combine with specific proteins to form hemoproteins. hemoglobin is a hemoprotein, as are many other substances essential to normal functioning of the cells and tissues of the body.

Two general types are known: the erythropoietic porphyrias, which are concerned with the formation of erythrocytes in the bone marrow; and the hepatic porphyrias, which are responsible for liver dysfunction. Manifestations of porphyria include gastrointestinal, neurologic, and psychologic symptoms, cutaneous photosensitivity, pigmentation of the face (and later of the bones), and anemia with enlargement of the spleen. Large amounts of porphyrins are excreted in the urine and feces.

Treatment of this condition has been primarily symptomatic and varies in its effectiveness. Emphasis is on prevention of attacks by avoiding fasting and drugs that precipitate the symptoms. Photosensitivity may be controlled by avoiding exposure to light. Removal of the spleen is useful in some cases of the erythropoietic type of porphyria. Drug therapy includes the use of phenothiazines, chlorpromazine and promazine in particular. These drugs allay pain and nervousness and apparently allow a period of remission from symptoms. Meperidine hydrochloride (Demerol) may be given for pain and hydroxypheme (Hemetin) is given intravenously to compensate for genetic impairment of heme synthesis.

Patients with porphyria must not be given barbiturates, sulfonamides, alcohol, or chloroquine as these chemicals may precipitate or intensify attacks. It is recommended that persons with this disease carry with them at all times identification saying that they have porphyria so that in an emergency they will not be given medication that could precipitate an attack or even death.
acute intermittent porphyria (AIP) a hereditary, autosomal dominant, form of hepatic porphyria manifested by recurrent attacks of abdominal pain, gastrointestinal dysfunction, and neurologic disturbances, and by excessive amounts of δ-aminolevulinic acid and porphobilinogen in the urine; it is due to an abnormality of pyrrole metabolism. Called also intermittent acute porphyria.
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. Called also Günther disease.
porphyria cuta´nea tar´da (PCT) the most common form of porphyria, characterized by cutaneous photosensitivity that causes scarring bullae, discoloration, growth of facial hair, and sometimes sclerodermatous thickenings and alopecia; it is frequently associated with alcohol abuse, liver disease, or hepatic siderosis. Urinary levels of uroporphyrin and coproporphyrin are increased. There are two main types: an autosomal dominant (or familial ) form in which activity of the affected enzyme is reduced to half normal in liver, erythrocytes, and fibroblasts; and a sporadic (but probably also familial) form in which the reduction is confined to the liver. Both types are believed to be heterozygous and clinical expression occurs in adulthood, precipitated by disease or environmental factors. A more severe homozygous form begins in childhood and is called hepatoerythropoietic porphyria.
erythropoietic porphyria porphyria in which excessive formation of porphyrin or its precursors occurs in bone marrow erythroblasts; the group includes congenital erythropoietic porphyria and erythropoietic protoporphyria.
hepatic porphyria porphyria in which the excess formation of porphyrin or its precursors is found in the liver; it includes acute intermittent porphyria, variegate porphyria, and hereditary coproporphyria.
hepatoerythropoietic porphyria (HEP) a severe homozygous form of porphyria cutanea tarda believed to result from an autosomal dominant defect in the same enzyme as is affected in porphyria cutanea tarda; it is clinically identical to that disease but onset is in early childhood and enzyme activity in liver, erythrocytes, and fibroblasts is virtually absent.
intermittent acute porphyria acute intermittent porphyria.
porphyria variega´ta (variegate porphyria (VP)) a hereditary, autosomal dominant, type of hepatic porphyria characterized by chronic cutaneous manifestations, notably extreme mechanical fragility of the skin, particularly areas exposed to the sunlight, and by episodes of abdominal pain and neuropathy. There is typically an excess of coproporphyrin and protoporphyrin in the bile and feces.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

por·phyr·i·a cu·ta·ne·a tar·da (PCT),

[MIM*176090, MIM*176100]
familial or sporadic porphyria characterized by liver dysfunction and photosensitive cutaneous lesions, with bullae, hyperpigmentation, and sclerodermalike changes in the skin and increased excretion of uroporphyrin; caused by a deficiency of uroporphyrinogen decarboxylase induced in sporadic cases by chronic alcoholism; autosomal dominant inheritance in familial cases.
Farlex Partner Medical Dictionary © Farlex 2012

porphyria cutanea tarda

Metabolic disease An AD condition caused by uroporphyrinogen decarboxylase deficiency Clinical Liver dysfunction, photosensitivity, hyperpigmentation, scleroderma-like skin changes Lab ↑ Uroporphyrin in urine
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

por·phy·ri·a cu·ta·ne·a tar·da

(pōr-fir'ē-ă kū-tā'nē-ă tahr'dă)
Familial or sporadic disorder characterized by liver dysfunction and photosensitive cutaneous lesions, with hyperpigmentation and sclerodermalike changes in the skin, and increased excretion of uroporphyrin; caused by a deficiency of uroporphyrinogen decarboxylase induced in sporadic cases by chronic alcoholism.
Synonym(s): symptomatic porphyria.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Porphyria cutanea tarda

An inherited disease that results in the overproduction of porphyrins.
Mentioned in: Hyperpigmentation
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Lee et al., "Low-dose hydroxychloroquine is as effective as phlebotomy in treatment of patients with porphyria cutanea tarda," Clinical Gastroenterology and Hepatology, vol.
Renal transplantation for porphyria cutanea tarda. New England Journal of Medicine, 33(11), 336, 811.
Acquired porphyria cutanea tarda in man and rat due to hexachlorobenzene intoxication [Letter].
Of hepatitis C patients, 0.8% of had porphyria cutanea tarda, 0.3% had lichen planus, 0.2% had vitiligo, 0.4% had membranoproliferative glomerulonephritis, and 0.1% had cryoglobulinemia.
* Today, the list of presumptive service-connected health problems caused by exposure to Agent Orange and other herbicides includes chloracne (a skin disease), Hodgkin's disease, multiple myeloma (a cancer of the blood cells), non-Hodgkin's lymphoma, porphyria cutanea tarda (a skin disease caused by a defective liver enzyme), respiratory cancers (lung, bronchus, larynx, and trachea), soft-tissue sarcoma (cancer of the muscles and tendons), acute and subacute peripheral neuropathy (weakening of the nervous system), prostate cancer, chronic lymphocytic leukemia, and adult-onset (Type 2) diabetes.
The porphyrias, of which porphyria cutanea tarda is only one, are disorders characterized by excessive excretion of porphyrins, pigments formed during the production of hemoglobin and excreted naturally in urine and feces.
High prevalence of the H63D HFE mutation in Italian patients with porphyria cutanea tarda. Hepatology.
Over the past 3 years, several high-profile gastroenterologists and dermatologists have called for routine HCV screening in patients with nonfamilial porphyria cutanea tarda or small-vessel vasculitis caused by essential mixed cryoglobulinemia (types II and III).
Other less common, specific manifestations of CKD patients on hemodialysis like acquired perforating disorders (1.3 % by Mirza et al.9), calciphylaxis (2% by Mirza et al.9), porphyria cutanea tarda and few others that were described in literature, only reactive perforating collagenosis was seen in our study in 2.7% frequency, 3.7% patients had onychomycosis.
* Porphyria cutanea tarda. This most common form of porphyria is characterized by increased sensitivity and fragility of the skin.
In the patient with porphyria cutanea tarda (PCT), a typical urinary uroporphyrin/heptaporphyrin ratio (range 2.1-4.3) was reported by all participants (6).