Biochemistry

Question 1

what is the scale that describes a person’s photosensitivity/skin type

Answer 1

Fitzpatrick skin scale

Question 2

example of a phototoxic porphyria

Answer 2

erythropoietic protoporphyria

Question 3

example of severe congenital porphyria

Answer 3

congenital erythropoietic porphyria

Question 4

describe congenital erythropoietic porphyria

Answer 4

AR condition with extreme sensitivity to sunlight developing disfiguring scars

other presentations include dystrophy of nails, blindness and brown discolouration of teeth

Question 5

define porphyria

Answer 5

heterogenous group of conditions caused by abnormalities in enzymes involved in making haem, resulting in overproduction of the intermediate compounds called porphyrins

Question 6

what is porphyria cutaenea tarda a deficiency of?

Answer 6

the enzyme uroporphyrinogen decarboxylase

Question 7

presentation of porphyria cutaenea tarda

Answer 7

bullous blisters (sunlight)
hyperpigmentation
hypertrichosis
solar urticaria
morphoea
liver disease may also be present (alcohol linked as a cause of this condition)

Question 8

investigations for porphyria cutaenea tarda

Answer 8

woods lamp

Question 9

management of porphyria cutaenea tarda

Answer 9

treat liver disease

Question 10

what is erythropoietic protoporphyria a deficiency of

Answer 10

ferrochelatase (AD)

Question 11

presentation of erythropoietic protoporphyria

Answer 11

irritation and burning pain in skin when exposed to sunlight

Question 12

investigations for erythropoietic protoporphyria

Answer 12

RBC
fluorocytes
USS of biliary tract

Question 13

management of erythropoietic protoporphyria

Answer 13

6 month LFTs
RBC porphyrins
photoprotection measures