article_snippet.sent: The condition – which is incurable - is caused by a build-up of a chemical called protoporphyrin in the blood.
article_snippet.sent: As blood passes through the skin, the protoporphyrin absorbs the energy from sunlight and this sets off a chemical reaction that can slightly damage surrounding tissues.
article_snippet.sent: EPP occurs when there is a build-up of a chemical called protoporphyrin in the blood.
article_snippet.sent: her skin is caused by a shortage of an enzyme in the body that normally converts the protoporphyrin into a substance called haem.
article_snippet.sent: As a result of this enzyme deficiency, protoporphyrin levels build up in the blood.
article_snippet.sent: As . blood passes through the skin, the protoporphyrin absorbs the energy .