[Erythropoietic protoporphyria. A rare differential diagnosis among photosensitive diseases]

A 31-year-old woman presented with recurrent swelling, burning, prickling and itching of the arms and the hands which appeared after UV exposure in the summer. Simultaneously she often had chills, malaise, nausea and circulatory problems lasting for hours. She did not have erythema or wheals. She had been seen by a number of specialties but to no avail. Her deceased mother suffered from the same symptoms. On presentation she had no skin lesions. Laboratory testing showed a dramatic increase in total protoporphyrin, enabling us to diagnose erythropoietic protoporphyria. This is a rare, genetic metabolic disturbance in hematopoiesis, whose true prevalence is probably underestimated. Because of abnormal or absent function of ferrochelatase, protoporphyrin accumulates in blood, erythrocytes and tissue usually causing photosensitivity as the first clinical symptom. The prognosis depends on the severity of liver involvement. Because of the marked restrictions on activity, especially in avoiding UV exposition, the quality of life of the patients and their families are strongly influenced. The odyssey of our patient and her mother in finding a diagnosis demonstrates impressively that the EPP is an important photosensitizing disease which must not be forgotten.