What is EPP?

"Erythropoietic Protoporphyria"

EPP patients react sensitive to the violet part of the light. More exactly to the light between 400 and 410 nm).

When the skin or part of the skin is a certain time in the sun, the afflicted person feel a painful  burning, which can stay about a few days. Sometimes the skin is reden, sometimes it is swollen. But most of the time you don’t see anything.

Therefore family, neighbours, friends, yes even doctors sometimes believe the EPP patients would simulate. Because this disease is rare, most of the doctors have never seen a EPP person.

The doctor’s advice ”don’t go into the sun” is not enough, because the light part which is responsible for the symptoms penetrate through the windows. Even indirect radiation, for example, under a sunshade, could arouse heavy symptoms with all bad consecuences for the EPP patient.

EPP was first limited from other kindred diseases in 1961. 1965 appeared the first article about EPP in the Netherlands .

The greek expression  ”erythropoietic” is put together of “erythro” (red, red blood corpuscle) and “poiesis” (=forming), so it means the formation of red blood cells.

The red blood cells are produced in the bone marrow. The red colour arises caused by the blood colouring matter, named haemoglobin. One part of the haemoglobin is called “heme”; which is the end product of a production chain called “heme synthesis “.At the last process of the synthesis protoporphyrin get build in the heme.

Responsible for this build is an enzyme, the ferrochelatase. The last step is defective in EPP patients, which leads to an accumulation of free protoporphyrin in the blood. Today it is supposed, that this mistake happens because ferrochelatase (build enzyme) of EPP-patients works defective.

The light influence stimulates the protoporphyrin, gets out of the cappilars and causes the typical pain and symptoms in the skin.

If other productions steps of heme-building, all likewise regulated by enzymes, not really work, the consecuence is an excess of porphyrins. All this diseases are named porphyrias.

Because of this EPP is a metabolic disease, caused by a genetic disorder.