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 skinâ€™s physical properties change dramatically in relation to different phases of the menstrual cycle.5 Such factors may modify the skinâ€™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 â€œsafer daysâ€ 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.
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.
The first and fourth treatments corresponds to phases of the menstrual cycle where both estrogen and progesterone have lower values, itâ€™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,