Color 14
Color 14
Eye colour, hair colour and skin colour are important risk fac- respectively (6). In a multicentre study on BCC and SCC from
tors for malignant melanoma and non-melanoma skin can- southern Europe, involving 1,549 BCC cases, 228 SCC cases
cers. There are few studies in which the distribution of these and 1,795 controls, pale eye colour compared to dark eye colour
pigmentary factors in risk populations has been assessed. The had an OR of 1.4 for BCC and 1.8 for SCC, and red hair colour
purpose of this study was to investigate the prevalence of the compared to black hair colour held an OR of 2.4 for BCC and
major eye and hair colours and the distribution of skin types 18.0 for SCC (9). Univariate estimations of OR without adjusting
and skin pigmentation in a Caucasian population. In 892 Dan- for exposure may be to underestimate the OR in sun-sensitive
ish Caucasians, eye colour, hair colour and skin type were persons because these individuals probably expose themselves
assessed and facultative and constitutive skin pigmentation less to the sun than more sun-resistant persons.
were measured objectively using skin re£ectance spectro- In most brown-skinned and black-skinned populations there
scopy. Blue eye colour and blond hair colour and skin type II is little variation in hair and eye colour, but in Caucasians a
were the most frequent (60%, 67% and 33% of subjects, great diversity of hair and eye colours is seen in connection
respectively). All four major eye colours and four major hair with various degrees of skin pigmentation. Despite eye colour
colours (with the exception of red hair colour) were found and hair colour being well-de¢ned risk factors for melanoma
within skin types I^IV and we could not predict the skin type and non-melanoma skin cancers, and are readily observable
or the constitutive skin pigmentation. Skin type could not be characteristics, surprisingly few studies assess the distribution
taken to classify individuals reliably according to their facul- of these pigmentary traits in Caucasian risk populations and
tative or constitutive skin pigmentation. Key words: epidemiol- the association of these pigmentary traits to skin type and to
ogy; risk factor; skin re£ectance. skin pigmentation.
(Accepted December 8, 1997.) The purposes of the present study were (i) to establish the
distribution of hair colour and eye colour and skin type and
Acta Derm Venereol (Stockh) 1998; 78: 214^219.
skin pigmentation in a Danish Caucasian population, which
JÖrgen Lock-Andersen, Department of Dermatology D92, has a high risk for development of melanoma and non-mela-
Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 noma skin cancers and (ii) to investigate whether eye colour
Copenhagen NV, Denmark. and hair colour are true predictors of skin type and skin pig-
mentation.
Persons of fair complexion, e.g. with blond or red hair and blue SUBJECTS AND METHODS
eyes and lightly pigmented skin, are clinically more prone to be The population sample consisted of patients and relatives attending the
sunburned and to develop sun-induced skin damage. In some outpatient clinic of the Department of Orthopaedics at the National
phototest studies the phenotypic characteristics eye colour and University Hospital in Copenhagen. This clinic was chosen because
hair colour have been found to be related to skin type and to persons of all ages and from a wide geographic area, including urban
minimal erythema dose (MED) (1^3). The incidence of skin and rural areas, attended the clinic and because we assumed that pig-
cancer, cutaneous malignant melanoma (CMM), basal cell mentary traits such as eye and hair colour and skin type would be unre-
lated to clinic attendance. In the study period, February to April 1995,
carcinoma (BCC) and squamous cell carcinoma (SCC), is
approximately 1,000 persons were approached randomly by one of two
increasing in white-skinned populations worldwide and skin
trained interviewers in the clinic's waiting area and invited to partici-
cancer is now becoming a major health problem. The fair pate in the study. We wanted the study to be a Danish population study
skinned Caucasians in Scandinavia are at considerable risk of and therefore excluded persons not holding Danish citizenship. Of
skin cancer and the CMM incidence rates are higher in Scandi- those approached, approximately 10% declined to participate for var-
navians than in populations from southern Europe (4). It has ious reasons. The study was approved by the local Ethics Committee
been calculated that, given the current incidence rates, 1 in and all participants gave informed consent before entering. Eight-hun-
every 100 Danish males and 1 in every 80 Danish females will dred-and-ninety-two persons were included (518 females and 374
develop a CMM during their lifetime (5). males), with a mean age of 37 years (SD~18 years; range 0^85 years).
In analytic studies of skin cancer it has been found that the Seven persons (0.8%) stated that they had previously had a skin cancer
or might have had a skin cancer. Since such information is doubtful,
phenotypic traits eye colour and hair colour and skin type and
and we could not verify this, they were not excluded.
skin colour are major risk factors for CMM (6, 7), BCC (8^10)
and SCC (8, 9, 11). In a meta-analysis of 10 case-control studies Study design
of CMM with more than 3,000 cases and almost 4,000 controls Study subjects were interviewed in a special study room in accordance
the odds ratio (OR) for blue eyes compared to brown eyes was with a standardized questionnaire on age, area of living, use of arti¢cial
calculated to be 1.6 and for red hair colour and blond hair colour tanning devices, hair colour and skin type. Eye colour was assessed and
compared to black or brown colours the ORs were 2.4 and 1.8, skin pigmentation was measured objectively at UV-exposed sites and in
Acta Derm Venereol (Stockh) 78 # 1998 Scandinavian University Press. ISSN 0001-5555
Skin pigmentation 215
Table I. Distribution of eye colour, hair colour and skin type about average; skin type IV: rarely burn, tan more than average; skin
type V: brown-skinned persons, and skin type VI: black-skinned per-
Pigmentary trait Study sample Subgroup sons. In children, the skin type was indicated by their parents but we
did not estimate skin type in persons younger than 6 years because we
Males, % Females, % MzF, % MzF, % consider anamnestic skin typing to be too uncertain or impossible
before this age.
Eye colourA
Blue 64.4 56.0 59.6 61.6 Skin pigmentation
Green 14.2 20.1 17.6 15.1 To objectively measure the skin pigmentation we used a portable skin
Grey 6.3 6.0 6.1 5.5 re£ectance spectroscope (PBI UV-Optimize, Model 550/660, PBI
Brown 13.7 17.9 16.1 16.8 Medical, Ringsted, Denmark) which utilizes wavebands of visible light
NA 1.4 0.0 0.6 1.0 at 555 and 660 nm to independently measure the skin pigmentation
Hair colourB (the melanin content) and the skin redness (the haemoglobin content)
Red 3.2 3.9 3.6 3.5 and gives the results on continuous scales from 0 to 100% (14). Zero
Blond 68.0 66.8 67.3 66.6 percent pigmentation corresponds to skin with no pigmentation at
Brown 23.8 27.5 26.0 25.4 all, as in an extremely white person; 100% pigmentation corresponds
Black 4.6 1.8 3.0 4.2 to no light re£ected back, as in theoretical absolutely black skin. The
NA 0.4 0.0 0.1 0.3 resolution of the pigmentation scale and precision of the instrument
Skin typeC allows for at least 40 steps for measurements of skin pigmentation in
I 21.0 24.7 23.1 24.9 European Caucasians (15). The measuring probe is held lightly against
II 32.8 33.9 33.4 29.0 the skin and after a few seconds the readings, which are the average of
III 19.0 15.8 17.2 16.1 three independent measurements, are given on the display. Before each
IV 26.3 22.8 24.3 27.9 measurement session the apparatus was calibrated on a white reference
V 0.6 1.0 0.8 0.8 tile. Pigmentation measurements were performed at UV-exposed sites:
NA 0.3 1.8 1.2 1.3 on the forehead; on the upper chest in the infraclavicular region; on the
upper back in the suprascapular region; at the lateral aspect of the
A subgroup of 414 persons, with an age and gender distribution as in upper arm 7 cm above the lateral epicondyle; at the medial aspect of
the Danish population, was constructed from the total sample of 892 the upper arm 7 cm above the medial epicondyle, and at the UV-
persons. A Eye colour assessed in study persons older than 1 year of age shielded site of the medial and upper quadrant of the buttocks. The
(study sample: n~868; subgroup: n~398). B Hair colour at 25 years of study period of February to April was carefully selected because the
age (study sample: n~667; subgroup: n~287). C Skin type in persons e¡ect of seasonal variation on facultative skin pigmentation is least
older than 5 years of age; in children indicated by their parents (study during these months of the year (16).
sample: n~856; subgroup: n~390). M~males; F~females; NA~not
available.
Statistics
The distribution of age and gender in the study sample was compared
using the Chi-squared test to the expected distribution calculated from
UV-shielded buttock skin. At the end of the examination study persons the Danish population as recorded by January 1996 (17). Analysis of
were given general advice on the risk known to be associated with eye colour, hair colour and skin type by gender was performed using
excessive sun exposure and on sun protection. The interview and the the Chi-squared test, and skin pigmentation by gender was analysed
pigmentation measurements took approximately 20 min for each per- using the unpaired t-test. Skin pigmentation according to skin types
son. The standardized questionnaire was pretested prior to the study, was analysed using the Mann-Whitney test. We considered p values less
and during the study the two interviewers at regular intervals over- than 0.05 to be signi¢cant.
heard each other's interview to ensure that interviews were being per-
formed consistently during the study period. Before starting the study
and at regular intervals during the study the two interviewers per- RESULTS
formed simultaneous assessments of eye colour in the same study per-
sons to ensure that eye colour assessment was uniform. Study sample versus the Danish population
Hair colour
Only 4% of the sample of Caucasians had red hair colour at the
age of 25 years and only 3% had black hair colour (Table I),
with blonds (light blond and dark blond) being the dominating
colours and with no statistical gender di¡erence (p~0.15). All
hair colours were found in the four skin types I^IV except red
hair, which was only found in skin types I and II (F|g. 1). There
was a tendency for brown and black hair colour to be asso-
ciated with the more sun-resistant skin types III and IV and
with a higher degree of constitutive skin pigmentation (Fig.
2), while blond and red hair were more associated with the
sun-sensitive skin types I and II and to lesser levels of constitu-
tive pigmentation. However, these were only weak trends and
overall hair colour was not found to be a predictor of skin type
or of the degree of constitutive skin pigmentation.
Fig. 1. Eye colour and hair colour according to anamnestic skin type.
Eye colour in 868 persons older than 1 year of age and hair colour at
Skin type and skin pigmentation
25 years of age in 667 persons.
Skin type II was the dominant skin type found in 33% of the
study persons (Table I), but a surprising 24% indicated skin
bution of eye and hair colour and skin types in the age and gen- type IV. There was no gender di¡erence in the distribution of
der population comparable subgroup (Table I). skin types (p~0.41). Facultative skin pigmentation at UV-
exposed sites was higher in females than in males except for
the forehead (Table II). Buttock skin pigmentation was also
statistically higher in females, but when solarium users were
Eye colour
excluded there was no signi¢cant di¡erence between constitu-
The dominating eye colour in the sample was blue with the fair tive skin pigmentation at the buttocks in either females or
eye colours (blue, green and grey) constituting the majority in males (13.3 vs. 12.8, p~0.18). More females than males were
both males and females; only 16% had brown eye colour (Table solarium users (33% of females and 14% of males). Considering
I). There was a gender di¡erence with more males having blue only persons that were not solarium users, females still had sig-
Upper arm, lateral 23.9 5.4 p~0.02 24.8 5.6 24.5 5.5
Chest 19.9 5.9 pv0.01 22.1 5.9 21.1 6.0
Back 19.8 5.5 pv0.01 21.2 5.6 20.6 5.6
Upper arm, medial 18.9 4.5 pv0.01 22.1 5.0 20.7 5.0
Forehead 18.1 5.4 p~0.39 17.8 5.0 17.9 5.2
ButtockA 13.3 5.5 pv0.01 14.8 5.6 14.2 5.6
ButtockB 12.8 4.8 p~0.18 13.3 4.8 13.1 4.8
Skin pigmentation measured by skin re£ectance spectroscopy at UV-exposed skin sites in all persons (facultative pigmentation) and at buttock skin
in all personsA (n~889) and in buttock skin of personsB not using arti¢cial tanning devices (n~666). Only in persons not using arti¢cial tanning
devices can the buttock pigmentation be considered to be the constitutive pigmentation. Statistical analyses of gender di¡erences by the unpaired
t-test.
ACKNOWLEDGEMENTS
We thank Mariane Bauer for invaluable help with data collection and
Age VÖlund for help with data analysis. The study was supported by a
grant from the Danish Cancer Society (Grant No. 94^037).
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