Follow-up studies of porphyrin excretion in porphyria cutanea tarda treated with p-aminobenzoic acid.

The treatment of porphyria cutanea tarda (PCT) with p-aminobenzoic acid (PABA) was suggested because PABA is capable of reversing the porphyrinogenic action of 3,5-dicarbethoxy-1,4-dihydrocollidine (DDC) in rats. Three patients with PCT were treated with 3 g of PABA daily during 6 and 12 months and the urinary and faecal porphyrin excretion were serially analyzed by solvent extraction techniques and by thin layer chromatography of their methyl esters. PABA treatment did not show any apparent effect on porphyrin excretion.