Porphyrias porphyria cutanea tarda

Acute intermittent porphyria Porphyria cutanea tarda... 

Porphyria cutanea tarda (hepatic) (MIM 176100) Hereditary coproporphyria (hepatic) (MIM 121300)... 

Porphyria cutanea tarda (very often associated with HFE mutations)... 

Deficiencies of other enzymes in the heme pathway produce porphyrias in which photosensitivity is a common finding. Chronic inflammation to overt blistering and shearing in exposed areas of the skin characterize these porphyrias. The most common is porphyria cutanea tarda (deficiency of uroporphyrinogen decarboxylase). 

Chronic porphyria, or porphyria cutanea tarda, is the most common form of the disease. 

Hydroxychloroquine is approved for the treatment of both systemic and cutaneous lupus erythematosus. Both chloroquine and quinacrine (Atabrine) are also effective in this skin disease. Low-dose chloroquine is used for the therapy of porphyria cutanea tarda in patients in whom phlebotomy has failed or is contraindicated. Other skin diseases in which the drugs are useful (after sunscreens and avoidance of sun exposure) include polymorphous light eruption and solar urticaria. 

Bleakley P, Nichol AW, Collins AG. 1979. Diazinon and porphyria cutanea tarda. Med J Aust 1(8) 314-315. 

HMBS hydroxymethylbilane-synthase, Intermediaries heptacarboxy-, hexacarboxy-and pentacarboxyporphyrins, MIM Nr Mendelian Inheritance in Man number, PCT porphyria cutanea tarda, Proto protoporphyrin IX, PV porphyria variegata, Uro uroporphyrin... 

If a patient presents with blisters due to photosensitivity, a plasma scan and fecal porphyrins will not only reveal the presence of a porphyria, but will also enable the distinction between the three forms that may cause such symptoms porphyria cutanea tarda (PCT), PV, and HC. Urinary porphyrins and eventually quantitative ALA und PBG in urine may be added in questionable cases or for monitoring of therapy. 

Fig. 7.3.3a-d Chromatogram of normal urine (a), urine from an individual with acute (in this case intermittent) hepatic porphyria (b), urine from an individual with porphyria cutanea tarda (c), and an undiluted sample from an individual with congenital erythropoietic porphyria (d). See typical pathological values for interpretation... 

Fig. 7.3.4a-c Chromatograms of fecal porphyrins, (a) from a healthy individual, (b) from an individual with porphyria cutanea tarda, and from an individual with porphyria variegata (c)... 

Congress had already declared that veterans who suffered from any of four diseases—chloracne, porphyria cutanea tarda, soft-tissue sarcoma, or non-Hodgkin s leukemia—were entitled to compensation. The IOM committee essentially endorsed the congressional decisions when it concluded that there was sufficient evidence for associations between herbicides and those four diseases. 

The 1996 IOM committee made findings about other two diseases. The committee downgraded IOM s evaluation of the evidence for associations between herbicide exposures and the rare metabolic disease, porphyria cutanea tarda, from sufficientto lim-ited/suggestive. Significantly, this decision indicates that the update committees can revise earlier classifications, but it makes no difference to VA compensation decisions. 

Skin eruptions in a patient with porphyria cutanea tarda. 

Urine from a patient with porphyria cutanea tarda (right) and from a patient with normal porphyrin excretion (left). 

Key concept map for heme metabolism. Note Porphyria cutanea tarda affects both the liver and erythropoietic cells. = Block in the pathway. 

This compound is poorly soluble in water and evaporates rapidly after release into the atmosphere. Due to its relatively high vapour pressure, it is usually found in the gas phase, not in the aerosol fraction. Today, its production is banned. However, it is present in many products as an impurity and can be released unintentionally. HCB has shown to be toxic for men, when in Turkish Kurdistan, between 1955 and 1959, it caused an outbreak of porphyria cutanea tarda after intake of contaminated food. A relationship between thyroid cancer increase and chronic exposure to HCB has been identified [22]. 

Porphyria can be precipitated by estrogens, and familial porphyria cutanea tarda can become manifest (32). 

Malina L, Chlumsky J. Oestrogen-induced familial porphyria cutanea tarda. Br J Dermatol 1975 92(6) 707-9. 

After short-term treatment with pravastatin, a 77-year-old woman transiently developed symptoms diagnosed as porphyria cutanea tarda (4). 

Schindl A, Trautinger F, Pernerstorfer-Schon H, Konnaris C, Honigsmann H. Porphyria cutanea tarda induced by the use of pravastatin. Arch Dermatol 1998 134(10) 1305-6. 

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