UROD and porphyria cutanea tarda: Porphyria Cutanea Tarda (PCT) is the most common cutaneous porphyria and manifests as photosensitivity, blistering, skin fragility, erosions, milia, and crusts on sun-exposed body areas.1, 2, 3 PCT is a hepatocutaneous disease of heme synthesis in which uroporphyrinogen decarboxylase (UROD) has reduced activity, resulting in the accumulation of porphyrins and heme intermediates in the liver and skin.1