How I treat erythropoietic protoporphyria and X-linked protoporphyria

Erythropoietic protoporphyria (EPP) is an inherited cutaneous porphyria caused by reduced expression of ferrochelatase, the enzyme that catalyzes the final step in heme biosynthesis. The resultant accumulation of protoporphyrin IX leads to severe, painful cutaneous photosensitivity, as well as potentially life-threatening liver disease in a small percentage of patients. X-linked protoporphyria (XLP) is clinically similar to EPP but results from increased activity of delta-aminolevulinic acid synthase 2, the first step in heme biosynthesis in the bone marrow, and also causes protoporphyrin accumulation. Although historically the management of EPP and XLP (collectively termed protoporphyria) centered around avoidance of sunlight, novel therapies have recently been approved or are in development, which will alter the therapeutic landscape for these conditions. We present 3 patient cases, highlighting key treatment considerations in patients with protoporphyria, including (1) approach to photosensitivity, (2) managing iron deficiency in protoporphyria, and (3) understanding hepatic failure in protoporphyria.

Automated summary

Erythropoietic protoporphyria (EPP) is a genetic disorder caused by reduced expression of ferrochelatase, leading to protoporphyrin IX accumulation and severe photosensitivity. X-linked protoporphyria (XLP) is similar but caused by increased activity of delta-aminolevulinic acid synthase 2. Novel therapies are changing the management and treatment landscape for these conditions.