What are the porphyrias?
A group of diseases which are caused due to an inborn error in the haem metabolism pathway, leading to the build-up of intermediate metabolites
How does porphyria cutanea tarda present?
Blistering, erosions and often milia on the face and backs of hands
How do sporadic cases of porphyria cutanea tarda classically show up in male and females respectively?
Males - Chronically high alcohol intake
Females - Taking oestrogen medications
Which porphyria is most common in Scotland?
Porphyria cutanea tarda
How is acute intermittent porphyria inherited?
In which area of the world is acute intermittent porphyria particularly common?
How does acute intermittent porphyria present?
Abdominal pain attacks
NO skin lesions
What actually causes the damage when porphyrins build up in the skin?
Sunlight activates porphyrins which promotes mediator release from surrounding inflammatory cells leading to a damaging inflammatory response
In which country is Variegate prophyria most common?
How does varigate porphyria present?
Symptoms of both porphyria cutanea tarda and acute intermittent porphyria
- Blistering, erosis and milia on the face and backs of hands
- Acute abdominal pain, dark urine, neuropsychiatric symptoms
What are porphyrins?
Intermediates within the haem synthesis pathway
Molecules are roughly circular in shape and may react to EM radiation
How is congenital erythropoietic porphyria inherited?
Which enzyme in the haem synthesis pathway has undergone a mutation in congenital erythropoietic porphyria?
Uroporphyrinogen III co-synthase
Congenital erythropoietic porphyria involves a build up of which porphyrin in the body?
How does congenital erythropoietic porphyria present?
Blistering (and scarring) of the skin
Pink fluorescing urine
How many enzymes are in the haem synthesis pathway?
The lak of activity from which enzyme is responsible for causing porphyria cutanea tarda?
Which colour will a patient's urine fluoresce under Wood's lamp if they are suffering from porphyria cutanea tarda?
Which inherited porphyria is most common in Scotland?
(porphyria cutanea tarda is the most common overall by 80% of cases are sporadic)
Why may nerve damage occur in a patient with acute intermittent porphyria?
There is a build up of porphobilnogen (PBG) due to lack or absence of functioning PBG deaminase
Eryhtropoietic and erythrohepatic protoporphyrias are most highly sensitive to which type of EM radiation?
At which stage in life does erythropoeitic protoporphyria present?
How does erythropoeitic protoporphyria present?
Discomfort, itch or tingling in sun exposed skin
There are often no clinical signs
Build up of which porphyrin, and lack of which functioning enzyme, causes erythropoietic protoporphyria?
Lack of ferrochelatase activity
Build up of protoporphyrin IX