Systemic lupus erythematosus (SLE or lupus) is a
multisystem disease with a tendency to cause skin
rashes. These often appear on the skin after
exposure to sunlight (for example face, neck, hands,
and feet). These rashes are called photosensitive
rashes and are one of the hallmarks of the disease
(see Lupus The Skin and Hair fact sheet). Some
patients complain of feeling unwell after going out in
the sun, even for relatively short periods of time, (in
extreme cases for as little as a few minutes). For
example, they may develop migraine, nausea (feeling
sick) or joint pains. The joints may even become
tender to the touch and swollen. These are all
manifestations of light sensitivity in lupus patients.
Other aspects of the disease may be exacerbated
after sun exposure, including fever, pleurisy (chest
pains on breathing in), kidney disease and more
serious nervous system problems such as epilepsy
(fits). Patients with severe light sensitivity may also be
adversely affected by fluorescent and halogen lighting,
energy-saving bulbs or any very bright light.
What is it in sunlight that causes lupus to flare and
causes rashes to develop in particular?
It is the ultraviolet (UV) waves in the sunlight. Ultraviolet
light in the UVA and UVB wavebands is responsible.
(Some light sensitive patients may also be harmed by
visible light, most commonly, but not necessarily only,
in the blue spectrum). UV light damages cells in the
skin (keratinocytes) causing them to die. In healthy
people without lupus, these dead cells are cleared
away quickly and any inflammation caused by the suninduced
skin damage is short-lived (sunburn).
However in lupus patients, the skin cells may be more
sensitive to sun-induced damage and there is
increasing evidence that the dying (apoptotic) cells are
not cleared away efficiently. As a result the contents of the dying cells may be released and cause
inflammation. Also, cell contents such as DNA (the
genetic material) and other molecules including Ro,
which are never normally exposed to cells of the
immune system, are available to generate (start) an
immune response. Immune responses and
inflammation are the normal reactions of the body to
infection, but here they are being generated
inappropriately by the dying cells and the body mounts
an immune response against its own cell constituents
(autoimmunity). The end result of this process in
susceptible people with certain types of lupus is the
development of characteristic photosensitive rashes.
Antibodies to Ro, in particular, are often found in
people with these rashes. Why the rashes affect only
some parts of the body at any one time and are not
always sun-sensitive is still not understood.
Why do some people with lupus get other disease manifestations
after sun exposure?
The immune response to cell constituents results in
the formation of these special proteins called
antibodies. The antibodies are made by white blood
cells called lymphocytes that circulate in the blood and
both the lymphocytes and the antibodies can travel to
different parts of the body.
These antibodies in lupus are directed against, and
bind to, particular molecules such as DNA and Ro.
These cell constituents may be released by other
dying cells in the body as it appears that the inability
to clear dying cells is not limited to the skin. Wherever
the antibodies and their target molecules meet up and
bind together, an immune complex is formed which
can set up a series of inflammatory processes causing
disease manifestations in that part of the body.
Having said this, it is still not entirely clear why different
people with lupus get certain disease manifestations
and not others.
Do all lupus patients suffer from light sensitivity?
No, about 60% of lupus patients get sun-induced
rashes and a further 10-20% complain of other clearly
sun-induced problems. The role of sunlight in the
remainder is unclear. Only a few people are confident
that sun exposure definitely does not affect them, as
they can go out for long periods and sunbathe without
any ill-effects then or in the following weeks. Because
new immune responses can take over a week to
develop, the effects of sunlight will not necessarily be
on the same day. In general, all lupus patients are
advised to avoid sun exposure as it is one of the
easiest ways of avoiding something which we know
can make lupus worse. It is also advisable to be alert
to the possible harmful effects of artificial lighting,
computers and television sets. (It is possible to
purchase screening devices which lessens the
radiation coming from these appliances).
Can photosensitive rashes and other sun-induced manifestations
of lupus be prevented?
Yes, to a large extent photosensitive rashes and
other sun-induced problems can be reduced by
keeping sun exposure to a minimum and using
sunblock regularly in the summer months (often from
April to October). This also means not going to hot
sunny countries or mountainous areas where there is
more UV light than in the UK. In particular, beware
of the increased UV exposure with snow, sea or
other water due to additional light reflected on to the
body (especially the neck and chin!). Even in the UK,
it is wise to avoid going out in the sun in the middle
of the day in summer. Sunblock should be sun
protection factor (SPF) 25 or greater and effective
against UVA and UVB light. It should be put on in the
morning and reapplied during the day (at least once
or twice) as it tends to get rubbed off or sweated
away, particularly in warm weather, and don't forget
your hands and feet!
Sunblock should be used even on cloudy days by
light-sensitive people because UV light can penetrate
the cloud layer and you can never tell what the
weather will be like later on. It is also advisable to
cover up with long sleeves and trousers and wear a
wide-brimmed hat when out in the sun. The use of UV
film on windows may also be necessary for those who
are particularly sun-sensitive. Patients who are
harmed by visible light will need to take further precautionary measures, such as amber window film or
blinds, which screen out the blue spectrum. It is
important for these patients to be assessed by a
Photobiology Centre so they know what level and
range of protection is needed.
How can I afford to buy so much sunblock?
Certain types of sunblock are available on prescription
for people with a sun-induced disease like lupus. The
general practioner (GP) usually prescribes the sunblock
but the GP may want advice from a hospital specialist
about which one to prescribe, how often and for how
long. Sunblocks which screen out visible light as well
are available on prescription. If you prefer a particular
sunblock that is not available on prescription then you
will have to pay for it yourself.
Do drugs provide protection against sun-induced flares
Yes, some drugs do help by damping down the
immune responses and inflammatory processes.
Steroids (for example prednisolone) will help to prevent
and treat lupus manifestations due to sunlight.
However, it is always best to be on the lowest possible
dose of steroids, so avoiding UV light and wearing
sunblock is important even if you are on steroids.
Hydroxychloroquine (Plaquenil) seems to be particularly
helpful at preventing rashes, arthritis and pleurisy which
may be sun-induced, but is not a replacement for
sensible behaviour. Other drugs (such as azathioprine,
methotrexate, cyclophosphamide) which are often
used for more serious disease or to keep the dose of
steroids as low as possible may also reduce the risks
of sun-induced flares.
Details of the practical aids mentioned above, as
well as many others can be obtained by requesting a
Product List for Light Sensitive Patients from