What initial workup do you perform when there is a concern for porphyria?

This is a terrific question. But a broad question. Porphyria refers to a defect in heme biosynthesis leading to the accumulation of porphyrins and porphyrin precursors. We should remember that there are three general categories of porphyria based on clinical manifestations: acute hepatic porphyria (acute intermittent porphyria, variegate porphyria, hereditary coproporphyria and the ultra-rare ALAD porphyria), blistering cutaneous porphyria (porphyria cutanea tarda and congenital erythropoietic p...