prophyria

Question 1

what are some types of porphyria

Answer 1

• porphyria cutanea tarda
• erythropoietic protoporphyria
• acute intermittent porphyria

Question 2

what is the most common type of porphyria

Answer 2

-porphyria cutanea tarda

Question 3

what is porphyria

Answer 3

a group of diseases in which substances called porphyrins build up, negatively affecting skin or NS

Question 4

cause of porphyria cutanea tarda

Answer 4

low levels of uroporphyrinogen III decarboxylase

-genetic and non-genetic (alcohol abuse, excess iron)

Question 5

cause of erythropoietic protoporphyria

Answer 5

deficiency in ferrochelatase, leading to abnormal levels of protoporphyrin in RBC, plasma, skin and liver

Question 6

cause of acute intermittent porphyria

Answer 6

deficiency in porphobilinogen deaminase

-attack caused by medication, alcohol, infections and change in sex hormone

Question 7

presentation of PCT

Answer 7

• blistering in sun exposed areas
• mila (wee white spots)
• hyperpigmentation
• hypertrichosis (excess hair)
• solar urticaria (hives etc)
• morphoea (thickening of dermis)

Question 8

presentation of erythropoietic protoporphyria

Answer 8

a few minutes of exposure induced erythema, swelling and pain
-after repeated exposure may present with lichnification, hypopigmentation, hyperpigmentation and scarring

Question 9

presentation of acute intermittent porphyria

Answer 9

severe and poorly localised abdominal pain

• urinary symptoms
• psychiatric symptoms
• signs that suggest increased sympathetic activity
• proximal muscle weakness beginning in arms

Question 10

diagnosis of PCT

Answer 10

woods lamp

• lab testing reveals high levels of uroporphyrinogen in urine
• if urine turns red on testing then condition is present

Question 11

diagnosis of erythropoietic protoporphyria

Answer 11

• quantitive RBC porphyrins
• detection of plasmatic fluorescence peak at 634nm
• increased levels of protoporphyrin in faeces or electrolytes

Question 12

diagnosis of acute intermittent porphyria

Answer 12

urine and serum show raised porphobilinogen

Question 13

treatment for PCT

Answer 13

• treat underlying cause
• avoid alcohol, iron and excess sunlight
• low dose of antimalarials can be used, work by removing excess porphyrins from liver

Question 14

treatment for erythropoietic protoporphyria

Answer 14

• avoid middle of day sunlight
• shade trees, windows ets
• topical sunscreen (ones containing zinc)
• prophylactic TL-01 phototherapy using UVB lamp
• antioxidants
• avoid iron

Question 15

treatment for acute intermittent porphyria

Answer 15

• high carbohydrate if drug caused

- hematin and heme arginate is treatment in acute attack