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Blistering disorders


Reviewer: Mowafak Hamodat MB.CH.B, MSc., FRCPC (see Reviewers page)
Revised: 5 September 2011 2011, last major update July 2011
Copyright: (c) 2002-2011, PathologyOutlines.com, Inc.


● 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

Porphyria cutanea tarda

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

Porphyria cutanea tarda

Porphyria cutanea tarda associated with HIV. Subepidermal bulla formation has resulted in loss of the epidermis. Note the rigid papillary dermal capillary walls.

Porphyria cutanea tarda: intense IgG staining on dermal size of basement membrane and around dermal blood vessels

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

eMedicine, National Library of Medicine

End of Skin-nontumor > Blistering disorders > Porphyria

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