Derm- photodermatology Flashcards
what is photosensitivity
photosensitivity describes a group of skin disorders that result from exposure to normal levels of UV light exposure
Fitzpatrick skin type 1
very fair skin
always burns
never tans
Fitzpatrick skin type 2
fair
usually burns
sometimes tans
Fitzpatrick skin type 3
medium
sometimes burns
usually tans
Fitzpatrick skin type 4
olive skin
rarely burns
always tans
Fitzpatrick skin type 5
brown skin
never burns
always tans
Fitzpatrick skin type 6
black skin
never burns
always tans
what is Xeroderma pigmentosum
a group of autosomal recessive genetic disorders caused by a deficiency in the DNA repair mechanisms in the skin
what is porphyria
porphyrias are a group of photosensitivity disorders resulting from an inherited or acquired defect in the enzymes required to produce adequate amounts of haem, with the subsequent accumulation of porphyrins
who does Acute intermittent porphyria most commonly affect
females around age 30
triggers of Acute intermittent porphyria
dieting
alcohol
medication changes
clinical features of Acute intermittent porphyria
acute abdomen
mood disturbance
neurological
seizures
which enzyme is deficient in Acute intermittent porphyria
Porphobilinogen deaminase
which porphyrin is accumulated in Acute intermittent porphyria
porphobilinogen
what is the most common type of porphyria
Porphyria cutanea tarda
who is Porphyria cutanea tarda most commonly seen in
middle aged men
what is Porphyria cutanea tarda associated with
liver disease
which enzyme is deficient in Porphyria cutanea tarda
uroporphyrinogen decarboxylase
which poprhyrin is accumulated in Porphyria cutanea tarda
uroporphyrinogen
clinical features of Porphyria cutanea tarda
blistering lesions on sun exposed sites that heal with scarring and are associated with hyperpigmentation
under a woods lamp, those with Porphyria cutanea tarda’s urine shines which colour
pink
under a woods lamp, which colour do normal individuals urine shine
blue
who is Erythropeotic protoprophyria most commonly seen in
children
which type of inheritance is Erythropeotic protoprophyria
autosomal dominant
which enzyme is deficient in Erythropeotic protoprophyria
ferricelatase
which porphyrin is accumulated in Erythropeotic protoprophyria
protoporphyrin IX
