Diode Laser 805 Hair Removal Side Effects in Groups of Various Ethnicities - Cohort Study Results.

Introduction: As hair removal has become most popular in aesthetics, the management of its side effects is crucial for every practitioner. Available studies describe the effectiveness of the diode laser hair removal for all skin types according to the Fitzpatrick scale independently, but the question of the occurrence of side effects and adverse effects remains unanswered. This study aims to illustrate aspects of side effects for patients of various ethnicities and the impact of those on the effectiveness of the treatment. Methods: The research was carried out in Poland and the United Kingdom from March 2016 to March 2019. 217 people of various ethnic origins were qualified for the study, 206 sessions were completed and statistical analysis was performed. The procedure was performed in the pubic area with diode lasers with a wavelength of 805 nm, minimum peak power of 2100 W and pulse duration between 15 and 400 ms. ET sapphire cooling assisted handle 9 x 9 mm large and pulse energy density between 10 and 100 J/cm2 were used for all treatments. In addition, in order to illustrate the effectiveness of treatments, the subjective and objective analyses of hair loss percentages were indicated. In statistical analysis, the chi-square test for independence was used to evaluate the correlation between the type and severity of side effects and the ethnic origin of patients, the number of treatments, the Fitzpatrick scale and the level of satisfaction. Results: The occurrence of sensitivity depended statistically significantly (P P =0.002) on ethnicity. Ethnicity had no significant effect on the occurrence of erythema. The occurrence of hyperpigmentation statistically significantly depended ( P <0.001) on ethnicity. The occurrence of burns depended statistically significantly ( P =0.001) on ethnicity. The number of treatments had a significant ( P P =0.012) effect on the severity of side effects occurrence. Among participants who had 6 treatments, only half had side effects, including multiple effects occurring in 9.79% of cases. The occurrence of side effects such as sensitivity and hyperpigmentation did not depend on the number of treatments. However, the number of treatments had a significant impact on the incidence of erythema ( P <0.001) and burns ( P =0.005). More than half of the respondents (58.33%) had erythema after more than six procedures, whereas in the 6 treatments the erythema occurred only in 6.7% of cases. Conclusion: The treatment with the use of diode lasers for all subjects with different ethnicity and thus the recognized scale according to Fitzpatrick is effective and safe. The occurring side effects are transient and do not impact the effect of the whole therapy.