Porphyrias with cutaneous findings

Question 1

What is the mainstay of treatment for porphyrias?

Answer 1

diligent photoprotection with physical sunblock, avoidance of skin trauma and good skin care

Question 2

What is the most common porphyria?

Answer 2

PCT

Question 3

PCT is due to:

Answer 3

decreased hepatic uroporphyrinogen decarboxylase (UROD) acticity

Question 4

What is the most common form of PCT?

Answer 4

acquired/sporadic

Question 5

What are the skin findings seen in PCT?

Answer 5

In photo distribution:

- vesicles

- bullae

- erosions

-milia

-scarring

- hyperpigmentation

- hypertrichosis

(classic pic is hemorrhagic blisters on dorsal hands)

Question 6

What is the pathogenesis of PCT?

Question 7

What are the associations/triggers in PCT?

Answer 7

• alcohol abuse, estrogen, hemochromatosis, hep C, HIV

Question 8

What is histology of PCT?

Answer 8

cell-poor subepidermal bulla w/ “festooning” of dermal papillae, “caterpillar bodies” (pink BMZ material in blister cavity and epidermis

• festooning epidermis is due to fibrosis that allows dermis to stay in tact within blister

Question 9

DIF findings of PCT?

Answer 9

IgG, IgM, fibrinogen, and C3 linearly along BMZ and in superficial dermal vessels (see thickened deposits around vessels)

Question 10

Tx of PCT?

Answer 10

avoid precipitating factors! (sunlight, alcohol, estrogen)

- phlebotomy for hemochromatosis

• low dose plaquenil and deferasirox

Question 11

X-linked dominant protoporphyria is due to ____mutation

Answer 11

gain of function ALAS2 gene that encodes 5-ALA

Question 12

Hepatoerythropoietic porphyria is due to (heterozygous/homozygous) mutation of ______

Answer 12

homozygous mutation of uroporphyrinogen decarboxylase (UROD)

Question 13

Hepatoerythropoietic porphyria starts at what age?

Answer 13

childhood/infancy

Question 14

Hepatoerythropoietic porphyria presents with what skin findings?

Answer 14

• scarring, sclerodermoid changes, photosensitivity to point of mutilation, hypertrichosis, milia, vesicles,

Question 15

Variegate porphyria is due to mutation of

Answer 15

protophrphyrinogen oxidase

Question 16

Hereditary coproporphyria is due to mutation in _____

Answer 16

coproporphyrinogen III oxidase

Question 17

Congenital erythropoietic porphyria (Gunther’s disease) is due to ____ mutation of ____

Answer 17

Autosomal recessive mutation of uroporphyrinogen III synthetase (UROS)—> overproduction of uroporphryin I and coporphyrin I in erythrocytes, plasma, urine, and feces

Question 18

Congenital erythropoietic porphyria (Gunther’s disease) will have ____ urine due to increased porphyrins excited by visible light

Answer 18

red

Question 19

Congenital erythropoietic porphyria (Gunther’s disease) exam of the mouth with woodslamp can reveal______

Answer 19

erythrodontia (teeth will fluoresce)

Question 20

most common porphyria seen in children is_____

Answer 20

erythropoietic porphyria

Question 21

​erythropoietic porphyria is caused by mutatino of _____

Answer 21

ferrochelatase mutation

Question 22

​erythropoietic porphyria presents as:

Answer 22

burning, stinging, itching 5-30 mins post sun exposure

• pruritic erythematous/edematous plaques lasting 1-2 days after sun exposure