What is Erythropoietic Protoporphyria?
Erythropoietic protoporphyria is a hereditary disease caused by sensitization to solar radiation.
Causes of Erythropoietic Protoporphyria
The disease is hereditarily predisposed and is transmitted in an autosomal dominant manner.
Pathogenesis during Erythropoietic Protoporphyria
The main place in the development of the disease is occupied by a violation of heme synthesis from protoporphyrin. Deposition of protoporphyrin in the skin causes photosensitization, however, the toxic effect of protoporphyrin on the skin is much weaker than that of uroporphyrin.
Symptoms of Erythropoietic Protoporphyria
In patients with erythropoietic protoporphyria, even after a short exposure to sunlight, edema, pruritus, redness appear on exposed skin, and the temperature often rises.
With a longer exposure to the sun, hemorrhagic rashes occur. Occasionally, there are blisters on the burn sites, which ulcerate and leave small scars. The patient can get a burn even through window glass, underwear made of synthetic fabric, since the rays with a wavelength of 380 nm, causing the burn, freely pass through the glass and synthetic fibers.
Diagnosis of Erythropoietic Protoporphyria
Erythropoietic protoporphyria, in contrast to erythropoietic urophorphyria, in most cases proceeds benignly. Of the complications, hypochromic anemia with a high iron content, a predisposition to stone formation in the gall bladder are sometimes observed, in more rare cases, a large number of porphyrins are deposited in the liver, and then liver failure forms.
Biochemically with erythropoietic protoporphyria, an increase in the content of protoporphyrin IX in erythrocytes is noted, and the contents of uroporphyrin and coproporphyrin remain within normal limits. In urine, the content of porphyrins is not increased, since protoporphyria does not pass into the urine. Significantly increased the amount of protoporphyrin and coproporphyrin in the feces, although not in all patients. It should be noted that a slight increase in erythrocyte protoporphyrin (up to 1.75-2.5 μmol / L with a norm of up to 0.8 μmol / L) is observed in many diseases – iron deficiency anemia, many hemolytic anemia, and lead intoxication. A characteristic feature of erythropoietic protoporphyria is an increase in the level of erythrocyte protoporphyrin by 20-100 times.
Treatment of Erythropoietic Protoporphyria
At the moment, there is no finally formed treatment option aimed at the mechanism of development of erythropoietic protoporphyria. The main route of exposure is protection from sun exposure with special hats, gloves, sunscreens. There are a number of reports of the use of carotene and carrot juice in erythropoietic protoporphyria. The results are contradictory, a convincing effect of these drugs has not yet been established.
The prognosis in most cases is quite favorable. It seems that over the years the condition of patients improves.