## 3 Results  
Researchers recruited 36 participants in this retrospective study; 23 were females (63.9%) and 13 males (36.1%). The mean reported age was 49.2 \(\pm\) 18.9 years. Participants' skin color ranged (using the Fitzpatrick scale) from type II (n = 7; 19.4%) to type III (n = 16; 44.4%) and type IV (n = 13; 36.1%). Hypermelanosis was present in the epidermis in 34 cases (94.4%); only 2 (5.6%) cases involved the dermis. Most hypermelanoses were located on the face (n = 33-91.7%), while there were only two lesions (5.6%) on the trunk and one (2.8%) on the extremities. Researchers needed up to four sessions to complete hyperpigmentation removal, with the mean number of treatments being 1.3 \(\pm\) 0.6. Melanosis can generally be safely and effectively removed in one or two sessions. Dermal lesions may instead require more treatments, up to four laser sessions. Clinical evaluation reported the maximum score in 25 patients (69%) treated for epidermal melanosis. The mean score was 3.61 \(\pm\) 0.60. Epidermal hyperpigmentations reported a score of 3.71 \(\pm\) 0.46, while dermal lesions reported a score of 2, showing overall lower effectiveness in the management of dermal lesions. The mean VAS score reported by participants was 9.39 \(\pm\) 0.90; patients treated for more superficial lesions had a higher score (9.57 \(\pm\) 0.56) than other types of lesions. Patients' age did not seem to influence VAS score results (Figure 4). Figure 5: (**A**) Solar lentigo before treatment; (**B**) region three months after the last session. Figure 6: (**A**) Hypermelanosis before treatment; (**B**) region three months after the last session. No serious adverse event occurred; treatment was well tolerated by all patients. After laser treatment, most of the participants reported transient perilesional erythema and edema, sometimes accompanied by itching, that spontaneously resolved in 1-3 days; regular progress after treatment included treated lesions becoming darker and covered by a flake/crusty formation, which exfoliated and turned into transient hypopigmentation until complete healing (no more visible effect) within 30 days. Patient characteristics are reported in Tables 1-3. \begin{table}
\begin{tabular}{c c} \hline \hline
**Patient No.** & **36** \\ \hline Female (\%) & 23 (63.9\%) \\ \hline Male (\%) & 13 (36.1\%) \\ \hline Mean Age \(\pm\) SD [years] & 49.2 \(\pm\) 18.9 \\ \hline Age range [years] & 19–76 \\ \hline _Fitzpatrick phototype:_ \\ \hline \(\Pi\) (\%) & 7 (19.4\%) \\ \hline \(\Pi\) (\%) & 16 (44.4\%) \\ \hline IV (\%) & 13 (36.1\%) \\ \hline _Hyperpigmentation depth:_ \\ \hline Epidermal (\%) & 34 (94.4\%) \\ \hline \(\Pi\) (\%) & 2 (5.6\%) \\ \hline \(\Pi\) (\%) & 33 (91.7\%) \\ \hline Extremities (\%) & 1 (2.8\%) \\ \hline Upper trunk (\%) & 2 (5.6\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Demographic data of included patients. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \begin{tabular}{c} **Mean No.** \\ **Sessions \(\pm\) SD** \\ \end{tabular} & \begin{tabular}{c} **No. Sessions** \\ **Range** \\ \end{tabular} & \
\begin{tabular}{c} **Dermatologist** \\ **Evaluation** \\ \end{tabular} &
\begin{tabular}{c} **Patient VAS** \\ **Score** \\ \end{tabular} \\ \hline All patients & 1.3 \(\pm\) 0.6 & 1–4 & 3.61 \(\pm\) 0.60 & 9.39 \(\pm\) 0.90 \\ \hline _Fitzpatrick phototype:_ \\ \hline II & 1.3 \(\pm\) 0.9 & 1–2 & 3.86 \(\pm\) 0.38 & 9.57 \(\pm\) 0.53 \\ \hline III & 1.1 \(\pm\) 0.3 & 1–4 & 3.63 \(\pm\) 0.72 & 9.25 \(\pm\) 1.18 \\ \hline IV & 1.3 \(\pm\) 0.8 & 1–2 & 3.46 \(\pm\) 0.52 & 9.46 \(\pm\) 0.66 \\ \hline _Hyperpigmentation depth_ \\ \hline Epidermal & 1.2 \(\pm\) 0.4 & 1–2 & 3.71 \(\pm\) 0.46 & 9.57 \(\pm\) 0.56 \\ \hline _Dermal_ & 3.0 \(\pm\) 1.4 & 2–4 & 2 & 6.5 \(\pm\) 0.71 \\ \hline _Hyperpigmentation location_ \\ \hline Face & 1.3 \(\pm\) 0.6 & 1–4 & 3.67 \(\pm\) 0.60 & 9.45 \(\pm\) 0.90 \\ \hline Extremities & 1.0 \(\pm\) 0.0 & 1 & 3 & 8 \\ \hline Trunk & 1.0 \(\pm\) 0.0 & 1 & 3 & 9 \\ \hline \hline \end{tabular}
\end{table}