Post inflammatory hyperpigmentation PIH, remains a major
hurdle in treating a variety of conditions in skin of
color, it is a complication seen in many procedures, such
as cutaneous lasers and chemical peels.1 This is especially true
with ablative resurfacing lasers, with rates reaching up to 32%.2
The mechanism behind it is unclear, but it is well known that patients
with darker skin are at risk. Other risk factors such as sun
exposure and certain laser parameters have been recognized.3
Despite precautions, PIH is still unpredictable and may arise
after a couple of laser treatments, even when using the same
laser parameters. This forces many to lower laser fluencies,
for safety concerns which may ultimately reduce the overall
efficacy or even have paradoxical results as the case with paradoxical
hypertrichosis secondary to laser hair removal.4
Hormones are linked to the physiology and pathology of skin
pigmentation. The skin’s physical properties change dramatically
in relation to different phases of the menstrual cycle.5 Such factors
may modify the skin’s response to the laser treatment. For
example, Melasma is a chronic pigmentary disorder, is known to
be precipitated by pregnancy and oral contraceptive pills.6 It is unknown
whether having laser treatments at specific menstrual cycle
days, corresponding to different hormonal levels, may increase
the risk of developing PIH, therefore would be better deferred to
“safer days†where higher fluences can be given with confidence.
For those reasons an experimental study is undertaken to study
the outcome of fractionated CO2 laser treatments given at four
predetermined days of the menstrual cycle to seven volunteers.
Materials and Methods
Laser treatment were given at four different days spanning their
menstrual cycle to their right inner arms in one month duration.
Volunteers who are having menses with skin type III or more are
recruited. Exclusion criteria included pregnancy, those who are
taking oral contraceptive pills, keloid prone patients and those
who had isotretinoin within the last year. The purpose and the
nature of the study were explained to the volunteers and the
study was approved by the ethical committee.
Treatment days were predetermined by a method used in natural
family planning,7 calculating the next anticipated day of
menstruation, NADM by adding the cycle length to the date of
the first day of the last menstrual period. Four specific days are
chosen because they represent important hormonal milestones
in the menstrual cycle and span the whole month. All patients
started their first laser treatment midway into the follicular
phase of the menstrual cycle. This is calculated by subtracting
21 days from the NADM. Second treatment coincides with
maximal estrogen secretion and it is calculated by subtracting
15 days from the NADM. The third treatment is calculated by
subtracting 7 days from NADM and coincides with maximal
progesterone secretion. Finally the last and fourth treatment is
done just prior to menses by subtracting
1 day from NADM. A CO2 fractionated laser device (Lutronic
CO2â„¢) was used using a 1000 micrometer tip, with a spot size
of 5 mm, a fluency of 160 mJ and a density of 20%. Photographs
were taken at 2 and 3 months to grade for dyspigmentation. Photos
were graded with a seven grade visual pigmentation scale,
with grade 1 being the mildest pigmentation and grade 5 being
the darkest. Grade 0 denotes no change and grade -1 is for hypopigmentation.
The grading is for each of the four treatments at
two time points; eight and twelve weeks after the last treatment.
Results
All Seven patients completed the study with all treatments being
tolerable with no anesthesia necessary. As shown in Table
1, four patients developed PIH, one had no pigmentary changes
and two patients developed mild hypopigmentation. The
scores of hyperpigmentation ranged from 1 to 4.
In those who developed hyperpigmentation, three out of four
patients had their maximal PIH at either the beginning and/or the
end of the menstrual period on their first and fourth treatments,
in other words, except for one volunteer, the pattern was that of
a deeper PIH when laser treatment is given just before or after
the menstrual period. The lowest scores were seen at the second
treatment, which corresponds to the day just before ovulation.
Discussion
The first and fourth treatments corresponds to phases of the
menstrual cycle where both estrogen and progesterone have
lower values, it’s not clear why would such time points have
higher scores in this study. It might be that these days closer
to menses, where half of normal women were found to have
darker skin than usual.8 It would have been interesting to test
during menses, where in addition to the luteal phase, lower
thresholds for pain were found.9 Painful laser treatments,
