Photodermatology and the Porphyrias

Question 1

what is cutaneous photosensitivity

Answer 1

Photosensitivity is an abnormal, cutaneous response to ultraviolet radiation and, in some individuals, visible light.

Question 2

what are the Fitzpatrick sun reactive skin phototypes

Answer 2

Fitzpatrick skin type 1

skin color (before sun exposure): ivory
eye color: light blue, light gray, or light green
natural hair color: red or light blonde
sun reaction: skin always freckles, always burns and peels, and never tans
Fitzpatrick skin type 2

skin color (before sun exposure): fair or pale
eye color: blue, gray, or green
natural hair color: blonde
sun reaction: skin usually freckles, burns and peels often, and rarely tans
Fitzpatrick skin type 3

skin color (before sun exposure): fair to beige, with golden undertones
eye color: hazel or light brown
natural hair color: dark blonde or light brown
sun reaction: skin might freckle, burns on occasion, and sometimes tans
Fitzpatrick skin type 4

skin color (before sun exposure): olive or light brown
eye color: dark brown
natural hair color: dark brown
sun reaction: doesn’t really freckle, burns rarely, and tans often
Fitzpatrick skin type 5

skin color (before sun exposure): dark brown
eye color: dark brown to black
natural hair color: dark brown to black
sun reaction: rarely freckles, almost never burns, and always tans
Fitzpatrick skin type 6

skin color (before sun exposure): deeply pigmented dark brown to darkest brown
eye color: brownish black
natural hair color: black
sun reaction: never freckles, never burns, and always tans darkly

Question 3

what is porphyria

Answer 3

Refers to a group of disorders that result from a buildup of natural chemicals that produce porphyrin in your body. Porphyrins are essential for the function of hemoglobin

Question 4

what are the main types of Porphyrias

Answer 4

Phototoxic skin Porphyrias

Blistering and fragility skin porphyrias

Acute attack Porphyrias (some with no skin involvement; some also cause blistering and fragility)

Severe congenital Porphyrias (such as congenital erythropoietic porphyria)

Question 5

what are typical presentations of porphyria cutenea tarda

Answer 5

blisters, fragility, hyperpigmentation, hypertrichosis, solar urticaria, morphoea

Question 6

what is the investigation for porphyria cutenea trada

Answer 6

A Wood’s lamp is a light that uses long wave ultraviolet light.

Question 7

how do you manage porphyria cutanea tarda

Answer 7

1. relieve the skin disease

2. treat the underlying diseases to reduce the risk of liver cirrhosis etc

Question 8

what is the clinical presentation of erythropoietic protoporphyia

Answer 8

often symptoms rather than signs eg prickly burning pain

Question 9

how do you manage erythropoietic protoporphyia

Answer 9

1. explain diagnoses: genetic counciling
2. 6 months LFTs and RBC porphyrins
3. visible light protection measures