Introduction to laser treatment
Vitiligo or leukoderma is a chronic skin pigmentation
disorder that causes white irregular patches on
the skin in different parts of the body. It is
caused by the destruction of pigment producing
melanocytes cells of the skin. The hair on vitiligo-affected
skin also sometimes turns white. Vitilogo treatment
is necessary since it can have a damaging psychological
impact on patients.
Traditionally, vitiligo has been treated by topical
steroids and phototherapy, for both local and genaralized
vitiligo. However, results were not satisfactory.
The pigment selective 308nm excimer laser promises
to improve on existing traditional therapies.
Laser treatment can be either monotherapy or combined
Monotherapy with lasers for vitiligo
A series of studies have shown the ability and
effectiveness of 308nm excimer laser to repigment
the skin. Using appropriate low fluences and one
to three sessions per week for one to six months,
these studies gave outstanding results, repigmenting
57% to 100% white patches. However, evaluation
must also consider the extent of repigmentation
of every patch. 75% repigmentaion is considered
satisfactory. In one series, 20 to 30% patches
attained this level of repigmentation. Another
series of studies gave conflicting results.
Of the several factors, which determine the rate
and extent of repigmentation of depigmented skin
patches, the loclization of the lesions seems to
play a critical role. The extent of repigmentation,
it seems, is influenced by localization of the
lesions. One study reported 75% repigmentaion on
all facial patches but none on the hands and feet.
The conflicting results in other studies indicate
that localization certainly plays a role in repigmentation.
The frequency of laser treatments can be once,
twice or three times a week. The rate of repigmentation
appears to be linked to the total number of sessions
and not to the frequency of sessions. It is difficult
to know the stability of the repigmentaion with
time, since the follow up studies were either too
short to be of any value or there were none. A
recent study found no depigmentaion at the end
of one year of treatment. According to other studies,
about 15% of new depigmentation was observed one
to three years after the end of treatment.
However, tolerance shown by patients to treatments
was usually very good. The immediate side effects
were restricted to erythema and rare blister lesions.
Combined therapy with lasers for vitiligo
The treatment of vitiligo lesions by the topical
0.1% tacrrolimus medication showed good results.
However, best results were obtained when exposure
to the sun accompanied treatment by topical tacrolimus.
As a resullt, two pilot prospective studies were
done to evaluate the combined therapy of 308nm
excimer laser and 0.1% tacrolimus ointment.
These studies compared the efficacy of the combined
therapy of excimer laser and tacrolimus ointment
with excimer laser monotherapy or laser combined
with a placebo. In the first therapy, two sessins
were performed in a week and in the second treatment
three sessions per week. In both therapies, 24
sessions were performed and 0.1% tacrolimus was
applied twice daily. On comparing the rsesults,
the combined therapy clearly stood out as superior
in terms of efficacy and short response time. Tolerance
was good and the immediate side effects were restricted
to constant erythema and rare bullous or itching
lesions. However, since these results were obtained
from a small population any action must await confirmation
from studies on larger populations.
The use of systemic tacolimus in organ transplant
patients exposes them to an increased risk of cutaneous
cancer. Therefore, for safety reasons, UV exposure
is restricted in local treatments with topical
tacrolimus, though, it must be stressed, the barrier
function of the vitiligo skin remains normal. However,
the restricted UV exposure results in poor penetration
of the tacrolimus ointment into the interfollicular
epidermis, affecting treatment response. Restricting
tacrolimus use has another disadvantage as demonstrated
in studies on mouse, where the tacrolimus was seen
to protect against any UV induced DNA damage. However,
since long-term follow up studies are lacking and
the risk of cancer cannot be completely eliminated,
the use of this combined therapy of excimer laser
and tacrolimus should, for the present, be restricted
to controlled studies.
The combination therapy of excimer laser and topical
steroids lacks proper evaluation. In the experience
of some, combination of 308 nm excimer laser and
one daily application of a class II topical steroid
have the potential to be a superior treatment to
laser monotherapy and nearly match the results
obtained in the combined therapy of excimer laser
and topical tacrolimus. If these results are confirmed,
then the combined excimer laser- topical steroid
therapy would represent a significant advance over
other treatments, since there would be no risk
of cancerous conditions developing.