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Metabolic disorders and reticulohistiocytic proliferative disorders
Published in Rashmi Sarkar, Anupam Das, Sumit Sethi, Concise Dermatology, 2021
The diagnosis is made by finding increased uroporphyrins and coproporphyrins in the urine and stool. A plasma spectrophotometry peak is seen at 615–620 nm. Iron overload is also a frequent, accompanying feature. Histologically, the blistering is subepidermal with festooning of the dermal papillae and, in the long-standing cases, fibrosis develops and deposits of immunoglobulin are found perivascularly.
Liver Diseases
Published in George Feuer, Felix A. de la Iglesia, Molecular Biochemistry of Human Disease, 2020
George Feuer, Felix A. de la Iglesia
The enzyme abnormality is present in the conversion of porphobilinogen to Type I and III porphyrins in the bone marrow. This abnormality is associated with a deficiency or absence of uroporphyrin isomerase.104,219 Normally the synthesis is shifted to the dominant formation of Type III porphyrins, which are used in heme synthesis. In congenital porphyria, since uroporphyrin isomerase is reduced, the amount of Type I porphyrin produced is very great, 100 mg or more per day. The Type I porphyrins are useless for the synthesis of the prosthetic groups; by not being degraded to bile pigments, they are excreted or deposited in the body. Therefore, pigmentation is a well recognized feature of the disease. In addition, photosensitivity of the skin due to porphyrins leads to various skin injuries. Compensatory mechanisms may allow the formation of normal heme, but uroporphyrin I and coproporphyrin I are markedly increased. The increase of uroporphyrin in the red cells causes hemolysis due to photosensitivity. The enhanced rate of hemolysis is compensated by an increased heme synthesis which further aggravates the condition through an increased production of Type I porphyrins as byproducts of the disease mechanism.
Sideroblastic Anemia and Porphyrias
Published in Harold R. Schumacher, William A. Rock, Sanford A. Stass, Handbook of Hematologic Pathology, 2019
In porphyria cutanea tarda, approximately 50% of patients demonstrate decreased activity of erythrocyte uroporphyrinogen decarboxylase. In acute intermittent porphyria, urinary levels of ALA or PBG or both are increased during and between attacks. In the neurocutaneous porphyrias, fecal porphyrins are increased during and between acute attacks. For example, in acute intermittent porphyria, normal or only slightly increased amounts of stool porphyrin are found. In variegate porphyria, protoporphyrin predominates in the stool, and there may also be increased amounts of coproporphyrin. In hereditary coproporphyria, coproporphyria predominate in the stool, and excretion of protoporphyrin is normal. In porphyria cutanea tarda, excessive amount of uroporphyrin occur in the urine.
Between a rock and a hard place: management of systemic lupus erythematosus and porphyria cutanea tarda
Published in Journal of Dermatological Treatment, 2022
Timothy Nyckowski, Alexandra Grammenos, Alisa Vinokurov, Rajiv Nathoo
Pathology revealed a cell poor subepidermal blister with festooning at base, and DIF illustrated IgG and IgA in a linear distribution along the basement membrane zone with thickening of the superficial dermal vessels; consistent with PCT (Figure 2). Laboratory findings included elevated quantitative porphyrins, most specifically elevated 24-h uroporphyrin further confirming the diagnosis. Of note, patient’s hemoglobin was consistently decreased around 10 g/dl and ferritin was significantly elevated. Additional pertinent laboratory findings included a speckled ANA (1:320 titer), SM/rNP > 8, DSDNA 6, C3 133 (normal), C4 33 (normal); AST 41, ALT 43, and Hepatitis C antibody that was non-reactive.
Porphyrias and photosensitivity: pathophysiology for the clinician
Published in Postgraduate Medicine, 2018
Loukas Kakoullis, Stylianos Louppides, Eleni Papachristodoulou, George Panos
In contrast, porphyrias in which the accumulated porphyrins are either uroporphyrin or coproporphyrin (PCT, VP, HCP, CEP) are not characterized by immediate photosensitivity but by the formation of blisters, sores and vesicles [11]. The paradigm for the pathophysiology of the cutaneous lesions is PCT, and both HCP and VP are described as having similar lesions as PCT [15]. CEP is also characterized by the formation of bullae and vesicles, but manifestations can be far more severe, as recurrent skin damage and secondary infections can lead to severe deformities and photomutilation [61].
Porphyria: awareness is the key to diagnosis!
Published in Acta Clinica Belgica, 2022
Benjamin Heymans, Wouter Meersseman
Whenever there is a clinical suspicion of a cutaneous porphyria, the total amount of plasma or urine porphyrins should be determined. In case of an elevation, a predominance of uroporphyrin and heptacarboxyporphyrin is diagnostic for PCT and these findings distinguish this disease from pseudoporphyria (in which the total amount of porphyrins is normal) and from other forms of cutaneous porphyria like congenital erythropoietic porphyria (where erythrocyte porphyrins will be elevated) [1].