More on the subject
Vitiligo, sun and skin cancer
commentary by Professor KU Schallreuter MD
Clinical Director of the Institute for Pigmentary Disorders in association
with E.M. Arndt Universiy of Greifswald/Germany and University of
This is a response to the special feature article in Dispatches 40 /
October 2005 of the UK Vitiligo Society and to a recent article in “The
Times” T2 Body and Soul section about the skin cancer risk in patients
suffering from vitiligo.
What is vitiligo?
This seems a redundant question.
However, it seems important to recognise that
vitiligo is a disease according to the World Health Organisation.
Vitiligo is neither a condition nor a symptom.
The characteristics of this disease are the acquired sudden loss of the
inherited skin colour. Despite its long recognition, the cause of this
disease is still unknown.
The loss of the skin colour yields white patches of various sizes which
can be localised anywhere on the body. The disease affects all races, men
and women and all age groups. Approximately 1 in 200 of the world
population develops vitiligo.
The affected individual shows often severe disfigurement, particularly
when the face and the hands are involved.
However, not all white skin patches are vitiligo. There are other
conditions and diseases which are associated with white skin. A long time
ago the term leucoderma has been introduced. This word originates from the
Greek language and means white skin. Clearly it seems mandatory to make
the correct diagnose. This can be done by Wood’s light. Vitiligo shows a
very characteristic fluorescence under this condition which is absent in
(Schallreuter et al, Science (1994))
Sutton Nevus (Halo-Nevus) is not vitiligo
Leukodermas of other origin are for example the Sutton Nevus also called
Halo-Nevus. Despite both vitiligo and Sutton nevus can occur together at
the skin of the same individual, it has been shown that these are two very
(Schallreuter KU et al Arch Dermatol Res (2004))
Future work needs to show why both vitiligo and Halo-Nevi frequently occur
Skin colour and sun protection
For decades it was believed that skin colour with its pigment (melanin)
content fosters sun protection. However, the sun protection factor (SPF)
is only between 2-3 for the brown / black melanin (eumelanin), while the
red pheomelanin hardly protects at all, it is even photoactive and
generates reactive oxygen species (ROS) (Chedeckel
MR and Zeise L, Lipids (1998, Johnson BE et al Nat New Biol (1972)).
It is becoming evident that besides melanin formation many other
mechanisms and factors are in place to defend the human body against
environmental reactive oxygen species (ROS) formation (Schallreuter
KU and Wood JM Photobiology (2001)). ROS can also be generated by
ultraviolet light directly inducing a plethora of signalling and defence
In vitiligo patches the pigment is mostly completely absent, but not all
individuals suffer from sun burn despite sun exposure (Schallreuter
KU et al, Dermatology (2002)).
Moreover, it has been documented at least in 2 major studies that vitiligo
per se does not necessarily coincide with increased sun sensitivity
(Calanchini-Postizzi E and Frenk E Dermatologica ( 1987); Schallreuter KU
et al (2002))
Skin ageing and vitiligo
Interestingly, the skin of vitiligo sufferers does not age with the same
speed compared to age and sex matched healthy people who do not have
KU et al (2002)). The results stem from a clinical study of patients
with vitiligo who did not avoid sun exposure completely. Hence, it would
be of great value to understand this phenomenon. This observation clearly
indicates that some other protective mechanisms must be in place to yield
However, it is also beyond any doubt that excessive sun exposure over time
can induce non melanoma skin cancer (NMSC) in general in susceptible
The development depends on the genetic background and on the accumulation
of sun exposure times / sunburns over time.
In this context it is noteworthy that fair skin people who always burn and
never tan are much more prone to develop skin cancer compared to good
tanners and dark skin coloured individuals. But there are also exceptions.
Even dark skin people can occasionally be very sun sensitive.
Vitiligo and skin cancer
The result of two major studies showed that patients with vitiligo do not
have a higher risk to develop sun induced skin cancer
(Calanchini-Postizzi E and Frenk E (1987) , Schallreuter KU et al (2002)).
In the recent past an issue was put forward that PUVA therapy which is a
frequently used treatment modality for vitiligo could be of potential risk
to enhance the risk of skin cancer and their precursors (actinic
keratosis) in these patients
(Halder RM et al Arch Dermatol(1995)). Considering the amount of rays
which these individuals receive, it seemed reasonable to question the
possible side effects. However, until now there is no documentation in the
literature about a true coincidence.
(Westerhof W and Schallreuter KU Clin Exp Dermatol (1997)). A recent
publication by Grimes states that there is also no enhanced risk after the
use of narrowband UVB exposure which is a treatment modality utilised as
mono therapy with increasing doses 2-3x per week in adults and even in
P, JAMA ( 2005)).
Vitiligo and melanoma
Malignant Melanoma (MM) is another skin cancer which can be very dangerous
if not recognised early. There are many reports linking this malignancy
with altitudes and excessive periodic sun exposure.
People with very fair skin (those who never tan or only very slightly) do
have a higher risk to develop melanoma compared to dark skin people at any
body site regardless of sun exposure or not. These tumours can develop in
existing moles but they can also arise totally new as pigmented as well as
non-pigmented tumours. Early recognition and excision are important for
The observation that melanoma is more frequent in patients with vitiligo
originates from a study which included 623 Caucasian patients with
melanoma of the Oncology Clinic at the Department of Dermatology at the
University of Hamburg/Germany
(Schallreuter KU et al, Dermatologica (1991)).
In this study 11/623 patients with melanoma had a true vitiligo long
before their melanoma was diagnosed. Considering that 1 in 200 has
vitiligo and 1 in 12,000 develops melanoma, these results suggested a
significantly higher risk to develop melanoma for patients with vitiligo
and fair skin (Schallreuter
KU et al, Dermatologica (1991)).
our Institute for Pigmentary Disorders we have indeed found in 2 Caucasian
patients with vitiligo melanoma in a patient group of 1800 Caucasian
patients with vitiligo supporting the above findings
(Schallreuter KU, unpublished results).
Based on the above results the take home message and recommendation is
that patients who have vitiligo should undergo an annual total body
examination at their Dermatologists in order to recognise a possible
melanoma as early as possible.
Melanoma associated leucoderma
Some individuals with melanoma develop patches of white skin in the
vicinity of their melanoma or after their tumour had been excised.
In this context it seems important that these white patches are not
vitiligo. This skin shows a very different molecular biology and
biochemistry compared to true vitiligo
(Kothari, S PhD Thesis U of Bradford 2005). Therefore the term
melanoma associated leucoderma seems more appropriate as already suggested
earlier by the late Fitzpatrick.
Are white skin patches associated with melanoma beneficial for the outcome
The development of white patches anywhere on the skin in association with
melanoma was interpreted to be a beneficial sign in the outcome for
survival time. There is still an ongoing debate whether the development of
such leucoderma associated with melanoma is of true value for the
individual’s outcome or not
(Lerner AB, Nordlund JJ Arch Dermatol (1977); Nordlund JJ, Lerner AB Arch
Dermatol (1979); Nordlund JJ et al J Am Acad Dermatol (1983)). This
author feels that there is at the present time not enough evidence to
support this statement. Larger patient groups are needed in order to
conclude. Therefore, it is simply not correct to advise patients with
vitiligo that they have a decreased risk to develop melanoma and that they
are well protected against this tumour.