UROD and Congenital erythropoietic porphyria: The intensity of the fluorescence peak varies with the activity status of the disease and is always positive in all symptomatic patients, including those with a suspected attack of acute porphyria in progress (ADP, AIP, VP, HCP) [18] and those with chronic high excretion of porphyrins (CEP, PCT, HEP, EPP).