RESUMO
Hereditary hemochromatosis is an autosomal recessive condition with incomplete penetrance that is most commonly caused by a mutation in the HFE gene. Hereditary hemochromatosis can remain asymptomatic in some patients until triggered by certain events. Porphyria cutanea tarda is a condition that can lead to iron overload due to defective synthesis of heme and can cause the onset of adult-onset hereditary hemochromatosis. Herein, we present a case where a 77-year-old man presented with painful blisters on the sun-exposed areas of his hands and was diagnosed with porphyria cutanea tarda. Further testing for mutations in the HFE gene given elevated ferritin was performed and returned positive, which confirmed the diagnosis of adult-onset hereditary hemochromatosis. The patient received serial therapeutic phlebotomy for iron overload and adopted lifestyle modifications such as avoiding sun exposure of upper extremities. The patient's blisters and laboratory iron panel parameters improved with continued phlebotomy. Therapeutic phlebotomy has been demonstrated to be an effective first-line therapy in patients with dual diagnosis. Our case highlights that cutaneous symptoms due to porphyria cutanea tarda may be the first presenting symptom in patients with underlying hemochromatosis.