Screening of patients with iron overload to identify hemochromatosis and porphyria cutanea tarda

Objective: To assess the importance of iron overload as a risk factor for porphyria cutanea tarda (PCT). Design: Prospective study during a 4-month period. Setting: Departments of emergency care, gastroenterology, and dermatology in a tertiary referral center. Patients: Patients were deemed eligible for inclusion in the study if serum ferritin levels were greater than 500 mu g/L (normal range: females, <125 mu g/L; males, <325 mu g/L). Main Outcome Measures: Porphyrin excretion profiles were analyzed on all patients included in the study, where clinically relevant. A diagnosis of PCT was confirmed biochemically in all cases. The HLA. typing was then performed on newly diagnosed cases of PCT. Results: Of 4127 patients tested, 240 patients with an elevated serum ferritin level were identified, of whom 74 had an elevated serum ferritin level of more than 500 mu g/L. Of the latter group, 17.5% had hemochromatosis and 6.7% had PCT. The incidence of PCT in the hemochromatosis group was 23%; HLA typing revealed the presence of at least 1 of the hemochromatosis markers. Conclusions: A high serum ferritin level in the absence of evident cause should prompt investigation for both hemochromatosis and PCT. The HLA heterozygosity for hemochromatosis in some patients with PCT may be a cause of hepatic siderosis.