Porphyria (redirected from Porphyrias)

porphyria [pȯr′fir·ē·ə]

(medicine)

A usually hereditary, pathologic disorder of porphyrin metabolism characterized by porphyrinuria and photosensitivity.

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Porphyria

comes in a winter storm to show her devotion, and her lover strangles her with her own tresses. [Br. Poetry: Browning Porphyria’s Lover in Magill IV, 247]

See : Love, Unrequited

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Porphyria

a disturbance characterized by an increase in the quantity of porphyrins in the blood and tissues and by their increased excretion in the urine. Porphyria is a basic disturbance in the metabolism of pigments in man.

Congenital porphyria is caused by a hereditary block of the conversion of porphobilinogen to uroporphyrinogen in the erythrocytes, resulting in an accumulation of porphyrins in the blood, organs, and tissues. Acquired porphyria occurs with poisonings, such as those caused by lead or barbiturates; with hypovitaminosis (pellagra); with some types of anemia and liver disease; and with alcohol abuse and overdose of sulfanilamides. Many of these substances, such as barbiturates, can provoke attacks of congenital porphyria that are often fatal. Porphyria is manifested by skin lesions and by gastrointestinal, neurological, and mental disorders. The skin lesions are manifested by photodermatosis in areas of the body exposed to light, since the porphyrins accumulating in the skin have a pronounced photosensitizing effect. Porphyrin photodermatosis is characterized by edema and by inflammation of the skin with violet erythematous pigmentation. Necrosis followed by the formation of deforming scars develops in severe cases. Gastrointestinal disorders are manifested by attacks of intestinal colic, vomiting, and constipation. Paresis, paralysis, and emotional instability occur in neurological and mental disorders associated with porphyria. Manifestations of photodermatosis are generally absent in pronounced neurological disorders. In porphyria, the urine contains a large quantity of porphyrins (coproporphyrin I or uroporphyrin), which impart a bloodred color to the urine. Treatment varies with the cause of the disease.

REFERENCES

Shteinberg, M. A. Fotodermatozy. Moscow, 1958.
Brugsch, J. Porphyrine, 2nd ed. Leipzig, 1959.

V. A. FROLOV