Photodermatology

Question 1

What is cutaneous photosensitivity?

Answer 1

How different people react to the sunlight based on their skin phototype (SPT 1-4)

Question 2

What is phototoxicity?

Answer 2

A mechanism of photosenstivity

Question 3

If a condition is photoaggravated, what does this mean?

Answer 3

The condition is not caused by the sun but is made worse by it

Question 4

What is a porphyria?

Answer 4

group of rare inherited or acquired disorders of certain enzymes that normally participate in the production of porphyrins and heme.

Question 5

What can porphyrias manifest as?

Answer 5

Neurological complications or skin problems or occassionaly both

Question 6

What are the 4 main groups of porphyrias?

Answer 6

phototoxic skin porphyrias
blistering and fragile skin porphyrias
acute attack porphyrias
severe congenital porphyrias

Question 7

What is erythropoietic protoporphyria and when does it present?

Answer 7

Presents in early childhood with disconfort, itch or tingling in sun exposed skin.
Caused by a build up of protoporphyrin IX due to a lack of ferrochelatase enzyme

Question 8

What is porphyria cutanea tarda and when does it present?

Answer 8

Caused by a deficiency in the enzyme uroporphyrinogen decarboxylase 
Presents in middle age with:
blistering 
scarring 
milia formation of dorsal hands/forearm 
often hypertrichosis

Question 9

The impaired function of what gives acute neurotoxic reaction to many tissues in acute intermittent porphyria?

Answer 9

porphobilinogen deaminase