Skin-nontumor / Clinical dermatology
Blistering disorders
Porphyria

Author: Mowafak Hamodat, M.D., MB.CH.B, MSc., FRCPC (see Authors page)

Revised: 17 June 2016, last major update July 2011

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PubMed Search: Porphyria [title] skin

Definition / General
  • Non-inflammatory blistering disorder due to disturbance of porphyrin metabolism (porphyrins are present in hemoglobin, myoglobin and cytochromes)
Clinical Features
  • Urticaria and vesicles that heal with scarring, and are exacerbated by sunlight
  • Types: acute intermittent, congenital erythropoietic, hepatoerythropoietic porphyria, porphyria cutanea tarda and mixed
  • Acute intermittent porphyria: second most common type of porphyria but still rare; autosomal dominant metabolic disorder with porphobilinogen deaminase deficiency; typically asymptomatic, but triggered by hormones, drugs and dietary changes; presents with abdominal pain or psychiatric symptoms; skin is typically not involved
  • Congenital erythropoietic porphyria: rare autosomal recessive disease with mutation in uroporphyrinogen-III synthase gene, leading to porphyrin accumulation in many tissues with marked skin photosensitivity, hemolytic anemia with splenomegaly and decreased life expectancy
  • Hepatoerythropoietic porphyria: rare (< 50 cases reported) autosomal recessive form of porphyria cutanea tarda, with markedly deficient activity of uroporphyrinogen decarboxylase (UROD); manifests during infancy or early childhood with extreme photosensitivity, skin fragility in sun-exposed areas, hypertrichosis, erythrodontia and pink urine; may resemble child abuse (Arch Dermatol 2010;146:529)
  • Porphyria cutanea tarda: Most frequent type of porphyria; autosomal dominant disorder due to catalytic deficiency of uroporphyrinogen decarboxylase (UROD), the fifth enzyme in heme biosynthesis (Best Pract Res Clin Gastroenterol 2010;24:735); reduced complement deposition during clinical remission (An Bras Dermatol 2010;85:827)
Clinical Images

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Porphyria cutanea tarda

Hepatoerythropoietic porphyria

Micro Description
  • Subepidermal vesicle, marked thickening of superficial dermal vessels (may appear rigid)
  • No/minimal inflammation
  • Porphyria cutanea tarda: dermal papillae protrudes into bulla with festooned pattern; roof of blister has eosinophilic, PAS+, and diastase resistant linear globules
Micro Images

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Porphyria cutanea tarda associated with HIV;
Subepidermal bulla formation has resulted in loss of
the epidermis (note the rigid papillary dermal capillary walls)

Positive Stains
  • IgG; to lesser extent IgM, fibrinogen and C3, outline donut–shaped blood vessels in the papillary dermis
  • Immunoreactivity also at the dermo-epidermal junction and within basement membrane region of eccrine sweat glands and ducts
Additional References