Racial differences Dan

Question 1

T/F

Dark skinned pts have more melanocytes than caucasians

Answer 1

False
Number/density of melanocytes the same across races
Amount and type of melanin varies - dark skin have more melanin and darker types of melanin

Question 2

T/F

Europeans have the smallest melanosomes

Answer 2

True
Africans largest melanosomes
Europeans smallest

Question 3

T/F

Melanosomes are evenly distirbuted in each keratinocytes in caucasians

Answer 3

False
mainly clustered at the nuclear membrane in caucasians
even distribution in africans
mixed pattern in asians

Question 4

T/F

The stratum corneum is of equal thickness across races but has more layers in black skin

Answer 4

True

Question 5

T/F

Black skin desquamates 5x more than caucasian skin

Answer 5

False

2.5x more

Question 6

T/F

African hair is elliptical with variable diameter along its length – like a twisted oval rod

Answer 6

True

Question 7

T/F

caucasian hair is the opposite of african hair

Answer 7

False
asian hair is fine and round
caucasian is mix between african and asian types

Question 8

T/F

Caucasians get more pattern baldness than other races

Answer 8

True

Question 9

T/F

longitudinal melanonychia occurs in 50% of afrocaribbeans

Answer 9

True

Question 10

T/F

Inflammatory skin disease in dark skin types more often causes folliculocentric and annular patterns

Answer 10

True

e.g. secondary syphylis

Question 11

T/F

acne is worst in asians

Answer 11

False

caucasians

Question 12

T/F

pityriasis rosea is twice as common in black people

Answer 12

True
Also;
Scalp more often involved
More itchy and persistent
PI hyperpigmentation common
Often need antihistamines and TCS, may need UVB for black pts

Question 13

T/F

Hypopigmentation is an important feature of seb derm in black people

Answer 13

True

Question 14

T/F

vitiligo is more common in dark skin types

Answer 14

False
but more noticable
Idiopathic guttate hypomelanosis is more common in dark skin

Question 15

How does MF differ in black skin pts?

Answer 15

Darkest skin types (types 5,6) prone to hypopigmented MF
Younger age of onset than classical MF
Hypopigmented MF shows loss of CD7+ cells
Patch stage hypopigmented MF usually indolent and responds well to phototherapy
Black pts present late in tumour stage, have more aggressive disease and poorer prognosis

Question 16

T/F

Traction alopecia and tinea capitis more common in afro-caribbeans

Answer 16

True

Question 17

What is Mossy foot?

Answer 17

= Podoconiosis
Lymphoedema of feet due to contact exposure to alkali clay soils. Presents in 20s.
Foot hygiene and wearing shows can reverse early changes

Question 18

T/F
The following are skin diseases mainly or exclusively seen in black people
Pseudofolliculitis barbae and acne keloidalis nuchae
Dissecting cellulitis
central centrifugal cicatricial alopecia
acrokeratoelastoidosis, keratosis punctata, pityriasis rotunda
Dermatosis papulosa nigra
Transient neonatal pustular melanosis
Facial afro-caribbean childhood eruption (FACE)
Sickle cell anaemia
HTLV-1 associated infective eczema – Caribbean eczema variant
Ainhum

Answer 18

True

Question 19

What is Facial afro-caribbean childhood eruption (FACE) ?

Answer 19

multiple small fleshy papules in perioral distribution in black kids age about 8
Cause unknown
Resolves in 3-5 years

Question 20

What are the 4 types of Kaposis sarcoma?

Answer 20

Classical – Ashkenazi jews and mediterraneans
Endemic - Africans
Epidemic – AIDS associated
Iatrogenic - in immunosuppressed pts