Photodermporphyrias

Question 1

Photodermatoses

Answer 1

Photo sensitive eruptions

Question 2

Give an example of a phototoxic skin prophyria

Answer 2

Erythropoietic protoprophyria

Question 3

Name a congenital porphyria

Answer 3

Congenital erythropoetic prophyria

Question 4

Commoner skin porphyria features

Answer 4

Blistering and fragility

Acute phototoxic

Question 5

Enzyme in porphyria cutanea tarda

Answer 5

Uroporphrinogen decarboxylase

Question 6

Presentation of PCT?

Answer 6

Blisters, fragility
Hyperpigmentation
Hypertrichosis
Soalr urticaria
Morphoea

Question 7

Investigation for PCT?

Answer 7

Woods lamp

Question 8

Underlying causes of PCT?

Answer 8

Alcohol
Viral hepatitis
Oestrogens
Haemochromatosis

Question 9

Aims of PCT treatment?

Answer 9

• Relieve the skin disease

- Treat the underlying diseases, to reduce risk liver cirrhosis, hepatoma, etc

Question 10

Enzyme in erythropoietic protoporphyria?

Answer 10

Ferratochelatase

Question 11

Presentation of erythropoietic protoporphryia?

Answer 11

Burning, itching and redness of skin on exposure to sunlight, blisters do not tend to form and scarring is minimal

Question 12

Erythropoietic protoporphria investigations

Answer 12

Quantitative RBC porphyrins
Fluorocytes (patient, relatives)
Transaminases
[Hb], red cell indices
(Biliary tract USS)
(Phototesting)

Question 13

FLUOROCYTES??

Answer 13

EPP

Question 14

Management of EPP?

Answer 14

Explain diagnosis; (genetic counselling)
6 monthly LFTs and RBC porphyrins

Prophylactic TL-01 phototherapy
Anti-oxidants (beta-carotene, cysteine, high dose vitamin C)
(Avoid iron)

Visible light photoprotection measures (particular need for caution if surgery needed)

Question 15

EPP and PCT method of inheritance

Answer 15

Autosomal dominant

Question 16

What would you give if incipient liver failure in EPP?

Answer 16

Oral charcoal
Cholestyramine
ALA synthase inhibition

Transplant liver? Bone marrow?

Question 17

Porphobilogen deaminase

Answer 17

Acute intermittent porphyria

Question 18

Symptoms may include vomiting, abdominal or back pain, weakness in arms or legs, and mental symptoms.

Answer 18

Acute intermittent porphyria
-first experience sudden onset of neurological symptoms

Differential:
Acute abdomen
Mononeuritis multiplex
Guillain-Barré syndrome
Psychoses