Porphyria (overview) E80.-

In 1874 Schultz probably described the first patient with porphyria (quoted n. J. Frank).

Group of rare, clinically and molecularly heterogeneous diseases with hereditary or acquired enzyme defects in haem biosynthesis. As a result of the specific, partial catalytic enzyme deficiency of one of the 8 enzymes in the enzyme chain, one or more intermediary products ( porphyrins) accumulate prior to the respective synthesis step and lead to a deficiency in the final heme product. The metabolites that accumulate in various organs develop cyto- and tissue toxic effects that define the respective clinical picture. Usually, further triggering factors are necessary to trigger the characteristic clinical symptoms, e.g. prophyrinogenic drugs, hormones, alcohol or UV radiation.

Currently, 8 types of porphyria are distinguished, which can be classified according to various criteria:

• Depending on the main site of the metabolic disorder, erythropoietic and hepatic porphyrias can be distinguished (see table 1).
• On the basis of the acute neurological porphyria attacks that occur in some forms, acute and non-acute forms can be further classified.
  • Acute porphyria:
    • Porphyria variegata
    • Coproporphyria hereditaria
    • Acute intermittent prophyria (Porphyria acuta intermittens)
    • Delta aminolevulinic acid dehydratase deficiency porphyria (Doss porphyria).
  • An acute syndrome with abdominal, psychiatric, neurological and cardiovascular symptoms develops clinically. A > 10-fold increase of porphobilinogen in the urine and is (except in Doss porphyria) decisive for the diagnosis
  • Non-acute porphyrias:
    • Porphyria cutanea tarda
    • protoporphyria erythropoetica
    • protoporphyria, X-linked dominant
    • Porphyria erythropoetica congenita.
  • In "non-acute porphyrias", accumulated porphyrins lead to light sensitivity of the skin (photodermatosis) and severe liver damage. Due to its position in the haemiosynthesis chain, the respective enzyme defect characterizes the diagnostically groundbreaking pattern of accumulated porphyrins. All non-acute porphyrias force the necessity of effective light protection.
• For differential diagnostic dermatological considerations, a classification into cutaneous and non-cutaneous porphyrias can also be made.
  • Cutaneous Porphyria:
    • Porphyria cutanea tarda
      • Type I: acquired or sporadic type
      • Type II: family type (50%)
    • protoporphyria erythropoetica
    • protoporphyria, X-linked dominant
    • Porphyria erythropoetica congenita
    • variegated porphyria
    • Coproporphyria hereditaria.
  • Non-cutaneous porphyrias:
    • Porphyria acuta intermittens
    • Delta-aminolevulinic acid dehydratase deficiency porphyria.

The prevalence of the various The prevalence of different forms of porphyria is unclear. Estimates for all known porphyrias are between 1:10.000 and 1:25.000 (J.Frank).

• Clinical findings with family history (cutaneous and/or neurovisceral symptoms)
• Biochemical tests in urine, stool, erythrocytes and plasma
• Enzymatic studies
• Molecular genetic analyses

Classification of primary porphyria

1. Frank J et al (2011) Hereditary metabolic diseases with cutaneous manifestation. Dermatologist 62: 98-106
2. Frank J (2011) Prophyrias. Dermatologist 67: 198-200