Photo-dermatology and porphyrias

Question 1

WHAT TEAM?!

Answer 1

WILDCATS

Question 2

What is a porphyria?

Answer 2

a rare hereditary disease in which there is abnormal metabolism of the blood pigment haemoglobin, can cause extreme sensitivity of the skin to light

Question 3

Name the 3 important porphyrais and their causative mutations

Answer 3

Acute intermittent porphyria- PBG deaminase

Porphyria cutanea tarda- uroporphinogen decarboxylase

erythropoietic protoporphyria- ferrochelatase

Question 4

Porphyria cutanea tarda

• presentation (6)
• investigations (2)
• management i.e. causes (4)

Answer 4

-bulla and erosion as a result of fragility
Milia- epidermal occlusion cysts
+ hyperpigmentation, hypertrichosis, solar urticaria, morphoea

-woods lamp (urine pink and fluorescent)
spectrophotometer

-treat cause: alcohol, viral hepatitis, oestrogen’s, heamochromatosis

Question 5

Erythropoietic protoporphyria

• presentation (1)
• investigations(5)
• management (6)

Answer 5

-swelling and redness aka sunburn, relieved by cold

-quantify RBC porphyrins
fluorocytes
transaminases
biliary tract US
Phototesting

-counselling
6 monthly LFTs
RBC porphyrins
\+ photo protection measures (behavioural/clothing/environmental/sunscreen)
cured via bone marrow transplant

Question 6

Acute intermittent porphyria differentials? (3)

Answer 6

-acute abdomen
mononeuritis multiplex
Guillan-barré syndrome