ContentsSynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyDrug Reaction DataReferencesView all Images (7)
Variegate porphyria - Skin
Print
Other Resources UpToDate PubMed

Variegate porphyria - Skin

Print Images (7)
Contributors: Vanessa Holland MD, Jeffrey D. Bernhard MD, Noah Craft MD, PhD, Lindy P. Fox MD, Lowell A. Goldsmith MD, MPH, Michael D. Tharp MD
Other Resources UpToDate PubMed

Synopsis

Variegate porphyria, also known as mixed porphyria, congenital cutaneous hepatic porphyria, and South African porphyria, is a blistering disorder caused by an autosomal dominantly inherited deficiency in protoporphyrinogen oxidase, a cytoplasmic enzyme involved in heme biosynthesis. Traditional classification distinguishes porphyrias as either erythropoietic or hepatic, depending on the location of the affected tissue. Variegate porphyria is thus considered hepatic given that the altered heme synthesis occurs primarily in the liver as opposed to the bone marrow. For practical purposes, it is also useful to classify porphyries as non-cutaneous versus cutaneous or acute versus non-acute forms. In this regard, variegate porphyria is considered a hybrid neurocutaneous porphyria, as the condition manifests with acute neurologic attacks in addition to the cutaneous findings.

The exact pathogenesis of the acute attacks is poorly understood. It is thought that certain porphyrin precursors – such as aminolevulinic acid and porphobilinogen – that are excreted by the liver in high amounts during attacks are potent neurotoxins.

Porphyrinogenic drugs, alcohol, hormonal changes, recurrent or chronic infections, and fasting or dieting (specifically carbohydrate restricting) may all precipitate an acute attack. Hepatic cytochrome p450 enzymes utilize heme as a cofactor; thus medications degraded by the body through induction of these enzymes may accelerate heme synthesis and accumulation of the neurotoxic porphyrin precursors in these patients, thereby precipitating an acute attack. Such medications include barbiturates, estrogen, griseofulvin, and sulfonamides, among others.

There is a high incidence of the condition in Afrikaners from South Africa.

Pediatric Patient Considerations:
Onset typically occurs after puberty.

For more information, see OMIM.

Codes

ICD10CM:
E80.20 – Unspecified porphyria

SNOMEDCT:
58275005 – Variegate porphyria

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

  • Porphyria cutanea tarda (PCT) – lacks the acute systemic findings, is more easily provoked, and presents with severe cutaneous findings. In variegate porphyria, the ratio of uroporphyrins to urinary coproporphyrin is usually 1:1 (or uroporphyrins < coproporphyrin), whereas in PCT, the ratio of uroporphyrins to urinary coproporphyrin is 3-8:1
  • Acute intermittent porphyria – lacks cutaneous findings
  • Other acute porphyrias – hereditary coproporphyria, d-aminolevulinic acid (ALA) dehydratase deficiency porphyria

Best Tests

Subscription Required

Management Pearls

Subscription Required

Therapy

Subscription Required

Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

Subscription Required

References

Subscription Required

Last Updated: 03/29/2017
Copyright © 2019 VisualDx®. All rights reserved.
Variegate porphyria - Skin
Print 7 Images
View all Images (7)
(with subscription)
Variegate porphyria (Cutaneous) : Bullae, Hypertrichosis, Photosensitivity, Recurring episodes or relapses, Skin erosion, Thickened skin, Vesicle, Sun-exposed distribution, Hyperpigmentation
Clinical image of Variegate porphyria
Copyright © 2019 VisualDx®. All rights reserved.