Efficacy and safety of laser shields to prevent radiant transmission onto pigmented nevi during laser epilation: An ex vivo histology study

Figures & data

Figure 1. A 23-year-old male requested epilation of the back. He has nevi, acne papules, and café-au-lait spots in the treatment area (hair had been shaved 1 day before the photograph in preparation for laser treatment).

Figure 2. (a) Measuring alexandrite transmission through a glass slide covered with clear glass, (b), measuring diode transmission through a glass slide covered with sun screen, (c) linear scanned hair removal laser emitting at 808 nm in test position, (d) application of a sufficient amount of zinc paste onto a skin explant using a cotton bud.

Figure 3. Histological changes after a single pass with an alexandrite laser (30 J/cm², 40 ms) on a skin explant of a congenital nevus half covered with (a) zinc paste, (b) PU foam, (c) sunscreen, and (d) wooden spatula.

Table I. Measured transmissions of various materials.

	Diode laser 808 nm 30 J/cm^2, 12 ms		Alexandrite laser 755 nm 30 J/cm^2, 40 ms
Cover material	Detected fluence (J/cm^2) Mean ± SD	Transmission (%)	Detected fluence (J/cm^2) Mean ± SD	Transmission (%)
Blank value	128.72 ± 1.25	NC	22.08 ± 0.25	NC
Glass slide	116.81 ± 3.25	100	20.16 ± 0.23	100
+Sunscreen	23.19 ± 0.39	19.85	3.41 ± 0.24	16.91
+PU foam	22.80 ± 0.24	19.52	4.19 ± 0.14	20.78
+Zinc paste	10.24 ± 0.21	8.77	1.61 ± 0.14	7.99
+Wooden spatula	10.36 ± 0.35	8.05	0.8 ± 0.22	3.62
+White kajal	89.28 ± 3.4	76.43	14.32 ± 0.26	71.03

NC, not calculated.