Porphyria cutanea tarda
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Porphyria cutanea tarda
Blood and lymphoreticular system
Anemia, cytopenias, and polycythemia anemias
Acute intermittent porphyria
Porphyria cutanea tarda
Autoimmune hemolytic anemia
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Hemolytic disease of the newborn
Hereditary spherocytosis
Paroxysmal nocturnal hemoglobinuria
Pyruvate kinase deficiency
Sickle cell disease (NORD)
Fanconi anemia
Folate (Vitamin B9) deficiency
Megaloblastic anemia
Vitamin B12 deficiency
Alpha-thalassemia
Anemia of chronic disease
Beta-thalassemia
Iron deficiency anemia
Lead poisoning
Sideroblastic anemia
Anemia of chronic disease
Aplastic anemia
Diamond-Blackfan anemia
Fanconi anemia
Aplastic anemia
Immune thrombocytopenia
Leukemoid reaction
Polycythemia vera (NORD)
Coagulation disorders (hypercoaguable and hypocoaguable conditions)
Antiphospholipid syndrome
Antithrombin III deficiency
Factor V Leiden
Protein C deficiency
Protein S deficiency
Hemophilia
Vitamin K deficiency
Disseminated intravascular coagulation
Heparin-induced thrombocytopenia
Von Willebrand disease
Bernard-Soulier syndrome
Glanzmann's thrombasthenia
Hemolytic-uremic syndrome
Immune thrombocytopenia
Thrombotic thrombocytopenic purpura
Infectious and immunologic disorders
Neoplasms
Langerhans cell histiocytosis
Mastocytosis (NORD)
Essential thrombocythemia (NORD)
Myelodysplastic syndromes
Myelofibrosis (NORD)
Polycythemia vera (NORD)
Acute leukemia
Chronic leukemia
Hodgkin lymphoma
Non-Hodgkin lymphoma
Monoclonal gammopathy of undetermined significance
Multiple myeloma
Waldenstrom macroglobulinemia
Traumatic, mechanical, and vascular disorders
Blood and lymphoreticular system pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Heme synthesis disorders: Pathology review
Intrinsic hemolytic normocytic anemia: Pathology review
Macrocytic anemia: Pathology review
Microcytic anemia: Pathology review
Non-hemolytic normocytic anemia: Pathology review
Coagulation disorders: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Platelet disorders: Pathology review
Thrombosis syndromes (hypercoagulability): Pathology review
Leukemias: Pathology review
Lymphomas: Pathology review
Myeloproliferative disorders: Pathology review
Plasma cell disorders: Pathology review
Flashcards
Porphyria cutanea tarda
0 of 7 complete
Questions
USMLE® Step 1 style questions USMLE
0 of 2 complete
A 45-year-old man presents to the office for evaluation of a blistering skin rash. He was out in the sun with his family at a baseball game several days ago. Later that evening, he developed a severe blistering rash on the forearms, hands, neck, and legs. He has tried over-the-counter topical emollients but to little effect. The patient has had similar rashes in the past that eventually self-resolved. The first of such episodes occurred around 10-years ago. Past medical history is also significant for hyperlipidemia and chronic hepatitis C virus infection. He does not consume alcohol, tobacco, or illicit substances. Vitals are within normal limits. Physical examination reveals small ruptured blisters diffusely across the forearms, hands, neck, and lower legs.
A defect in which of the following steps of the heme biosynthesis pathway is most likely responsible for this patient’s symptoms?
A defect in which of the following steps of the heme biosynthesis pathway is most likely responsible for this patient’s symptoms?
External References
First Aid
2024
2023
2022
2021
Porphyria cutanea tarda p. 430
Sporadic porphyria cutanea tarda p. 172
Summary
Porphyria cutanea tarda is a rare metabolic disorder that is caused by an abnormality in the enzyme uroporphyrinogen decarboxylase. Symptoms of this disorder usually involve the skin, as it can lead to blisters and skin discoloration. Treatment for this disorder usually involves medications such as hydroxychloroquine and phlebotomy, as well as lifestyle changes such as avoiding alcohol.