WHAT IS PORPHYRIA?
The term
porphyria refers to a group
of diseases in which, as a result
of a metabolic defect, there is
an overproduction of substances
known as porphyrins.
In most cases the defect is genetic,
and a
mutation carried within a
family results in a faulty
enzyme which cannot handle
the normal metabolism of porphyrins,
with a consequent overproduction.
One form of porphyria (porphyria
cutanea tarda), is however
usually not genetic, but is acquired
or "picked up" as a result
of certain forms of liver dysfunction.
In this case, the defect is found
only in the patient and not in his
or her family.
SYMPTOMS
 In
general, patients with porphyria
have only two major symptoms: the
acute attack and
skin photosensitivity. It
is important to realise that not
every porphyria is associated with
both problems, and you should be
sure in your own mind of which type
of porphyria you have and what its
possible effects are. The types
of porphyria and their effects are
outlined below
The
acute attack is a serious condition
which arises during a time of particularly
active porphyrin overproduction,
and may follow exposure to a wide
range of drugs and medications which
stimulate the production of porphyrins.
It is felt by the patient as an
attack of severe abdominal pain,
possibly with nausea, vomiting,
constipation and pain in the limbs
and back. It may potentially deteriorate
into a state of paralysis, and is
therefore dangerous. Fortunately
however, there is very effective
treatment available which will prevent
this provided the attack is recognised
and treated early.
 The
skin disease takes the form of easy
blistering and development of sores,
scabs and scars in sun-exposed areas,
particularly the backs of the hands
and face.
TYPES OF PORPHYRIA
There are seven
types of porphyria, each differing
slightly according to the specific
enzyme which is defective. The clincial
symptoms overlap however.
Acute intermittent porphyria
(AIP) and
ALA dehydratase deficiency (Doss)
porphyria are associated
with acute attacks only, but no
skin disease.
Porphyria cutanea tarda (PCT)
,
erythropoietic protoporphyria
(EPP) and
congenital erythropoietic porphyria
(CEP) are associated only with skin
disease, but not with acute attacks.
Variegate porphyria (VP)
and
hereditary coproporphyria
(HCP) are associated with both.
Variegate porphyria is common in
South Africa, The other forms of
porphyria are also encountered in
South Africa, but less frequently.
FURTHER INFORMATION
You will find more
information on each of these porphyrias
by clicking the entry for each on
the menu. Read our handbook for
patients as well as the many reference
pages available on this site. Further
information about any aspect of
porphyria can be obtained from our
Porphyria Information Centre.
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