Itch Scores
Median itch scores are shown in Figure 2. Since visual inspection revealed that median values were identical for both lasers, values are not separated according to the laser. Values varied from 2 to 4 during the initial visits and decreased to 2 by the end of the study. The median itch score at the end of the study was significantly lower than the baseline value (P=0.0156).
Median itch scores are shown in Figure 2. Since visual inspection revealed that median values were identical for both lasers, values are not separated according to the laser. Values varied from 2 to 4 during the initial visits and decreased to 2 by the end of the study. The median itch score at the end of the study was significantly lower than the baseline value (P=0.0156).
DISCUSSION
The efficacy of the 650-microsecond laser has been shown to be equivalent to that of the excimer laser for the treatment of mild to moderate psoriasis vulgaris of the arms and legs. Differences were not significant for redness, thickness, scaliness, mPASI scores for arms and legs, and overall mPASI scores. As shown in Figure 1, the median overall mPASI scores for both lasers were identical for all except treatment 4. As expected, the values decreased rapidly until visit 10 when they leveled off at 1.3 and decreased 1.2 at the end of the study. Tolerance of both laser treatments was excellent as shown by the Table 7 data. Erosion/ulceration and erythema were 1 or 2 and scaling was 3 in some cases. Although pain during and after treatment was greater with the 650-microsecond laser than with the excimer laser (Table 8), this did not discourage any subject from completing the study.
A recent roundtable discussion12 includes the experience of one author (Dr. Nazanin Saedi) on the use of the 650-microsecond laser for treating plaque psoriasis. The author states, “I've had really good experience with plaque psoriasis patients who have either failed topical therapy, have hard-to-treat areas, or been sick or non-compliant with topicals. We see improvement shortly after initial treatment. For example, I had a woman, skin type II, with it (psoriasis) on the ear. I used the 6-mm spot at level six and four passes. A week after her first treatment there's barely anything left.” This preliminary finding agrees with the results of the present study.
The 650-microsecond Nd:YAG 1064nm laser offers unique features not available in other devices. Its 650-microsecond pulse duration causes minimal pain during treatment of skin of color without anesthetic or skin cooling. Since the pulse duration is shorter than the thermal relaxation time of both the skin and blood vessels, the therapeutic target is heated more rapidly than the rate heat is conducted to the surrounding skin, thus reducing damage and lowering the risk of pigmentary alterations.14 The 650-microsecond laser also delivers energy in a collimated beam, so the operator may vary handpiece-to-skin distance without changing the fluence. This enhances both efficacy and safety during treatment and renders treatment less dependent on operator technique.16 Clinical examples of the treatment of psoriasis with the 650-microsecond laser are shown in Figures 3 through 5.
A recent roundtable discussion12 includes the experience of one author (Dr. Nazanin Saedi) on the use of the 650-microsecond laser for treating plaque psoriasis. The author states, “I've had really good experience with plaque psoriasis patients who have either failed topical therapy, have hard-to-treat areas, or been sick or non-compliant with topicals. We see improvement shortly after initial treatment. For example, I had a woman, skin type II, with it (psoriasis) on the ear. I used the 6-mm spot at level six and four passes. A week after her first treatment there's barely anything left.” This preliminary finding agrees with the results of the present study.
The 650-microsecond Nd:YAG 1064nm laser offers unique features not available in other devices. Its 650-microsecond pulse duration causes minimal pain during treatment of skin of color without anesthetic or skin cooling. Since the pulse duration is shorter than the thermal relaxation time of both the skin and blood vessels, the therapeutic target is heated more rapidly than the rate heat is conducted to the surrounding skin, thus reducing damage and lowering the risk of pigmentary alterations.14 The 650-microsecond laser also delivers energy in a collimated beam, so the operator may vary handpiece-to-skin distance without changing the fluence. This enhances both efficacy and safety during treatment and renders treatment less dependent on operator technique.16 Clinical examples of the treatment of psoriasis with the 650-microsecond laser are shown in Figures 3 through 5.
