1983 Volume 45 Issue 3 Pages 383-392
Five cases of porphyria cutanea tarda with mild cutaneous changes are reported. Hyperpigmentation and small scars on the exposed areas were the most significant cutaneous changes. Acute episodes of photosensitivity were nil. All patients admitted to a long history of excessive alcohol intake. The abnormality of the liver function tests was determined by another physician before the first examination in our clinic. The laboratory examinations showed a predominance of uroporphyrin in the urine in 4 of 5 cases. In one patient, there was a relatively low urinary porphyrin level, despite an abnormal porphyrin pattern. In four there was a predominance of uroporphyrin in the urine as well as a high level of serum coproporphyrin. Histopathologically, all had a deposition of PAS positive materials surrounding the small blood vessels in the upper dermis, in addition to the deposition of IgG materials determined using immunofluorescence. The diagnosis of porphyria cutanea tarda cannot be accurately made on the histopathological and laboratory findings only. Furthermore, some caution is needed for a diagnosis of this disease because of slight cutaneous changes in recent cases. A phlebotomy was performed in one patient. The urinary porphyrin level gradually reverted to normal and we determined that the urinary porphyrin pattern shifted from uroporphyrin and hepta-carboxyl porphyrin predominance to coproporphyrin predominance. We therefore speculate that a phlebotomy normalizes the uroporphyrinogen decarboxylase activity. Although the mechanism of action of the phlebotomy is unknown, an analysis of the urinary porphyrin profile is a useful laboratory tool for the diagnosis or for the progress of the course of porphyria cutanea tarda, as well as for a quantitative analysis of urinary porphyrins.
