applied sciences Article Q-Switched 1064/532 nm Laser with Picosecond Pulse to Treat Benign Hyperpigmentations: A Single-Center Retrospective Study Martina Silvestri 1,2, Luigi Bennardo 1,3 , Elena Zappia 1, Federica Tamburi 1, Norma Cameli 2, Giovanni Cannarozzo 4,* and Steven Paul Nisticò 1 1 Department of Health Sciences, Magna Graecia University, 88100 Catanzaro, Italy; [email protected] (M.S.); [email protected] (L.B.); [email protected] (E.Z.); [email protected] (F.T.); [email protected] (S.P.N.) 2 San Gallicano Dermatological Institute, IRCCS, 00100 Rome, Italy; [email protected] 3 Unit of Dermatology, Mariano Santo Hospital, 87100 Cosenza, Italy 4 Unit of Dermatology, Tor Vergata University, 00100 Rome, Italy * Correspondence: [email protected]; Tel.: +39-09613647195 Abstract: (1) Benign melanoses are a frequent issue in aesthetic dermatology. Solar lentigo, ephelides, café au lait spots, and other melanoses represent a cosmetic issue for a growing number of subjects. The Q-switched 1064/532-nanometer (nm) laser may be considered the gold standard for manage- ment of these aesthetic issues. A new generation of Q-switched lasers, capable of concentrating the energy pulse in the spectrum of hundreds of picoseconds, is emerging, promising better results than previous ones. In this paper, we report the use of a Q-switched laser with a picosecond pulse to Citation: Silvestri, M.; Bennardo, L.; manage hypermelanoses. (2) Methods: 36 patients seeking melanosis removal were retrospectively Zappia, E.; Tamburi, F.; Cameli, N.; enrolled at Magna Graecia University of Catanzaro. Treatment parameters, although variable, were Cannarozzo, G.; Nisticò, S.P. the following: 1064 nm with a pulse duration of 450 picoseconds (ps) for dermic lesions and 532 nm Q-Switched 1064/532 nm Laser with with 370 ps for epidermal lesions. Up to four treatments, with a minimum interval between laser Picosecond Pulse to Treat Benign treatments of 30 days, were performed. After the last session, patients’ satisfaction was assessed at a Hyperpigmentations: A Single- three-month follow up with a Visual Analogue Scale (VAS). Two blinded dermatologists measured Center Retrospective Study. Appl. Sci. the aesthetic outcome using a five-point scale comparing pictures before laser sessions and during 2021, 11, 7478. https://doi.org/ follow-up. (3) Results: 36 patients were enrolled; 23 were females (63.9%) and 13 males (36.1%). The 10.3390/app11167478 mean reported age was 49.2 ± 18.9 years. All participants were assessed with a complete/almost ± Academic Editor: Anming Hu complete melanosis removal at the dermatological evaluation, with a mean VAS score of 9.39 0.90. (4) Conclusions: The Q-switched 1064/532 nm laser may be considered the main weapon in treating Received: 4 July 2021 benign hypermelanosis. The picosecond pulse seems to guarantee better results than other devices. Accepted: 12 August 2021 However, a clinical trial comparing Q-switched nanosecond pulse with picosecond pulse is necessary Published: 14 August 2021 to confirm this study’s findings. Publisher’s Note: MDPI stays neutral Keywords: Q-switched laser; benign hyperpigmentations; melasma; solar lentigo with regard to jurisdictional claims in published maps and institutional affil- iations. 1. Introduction Melanosis’ elimination for cosmetic reasons is a common request in aesthetic der- matology [1–4]. Hyperpigmentations can be described as the darkening of the skin sec- Copyright: © 2021 by the authors. ondary to melanin increasing in skin layers. Different procedures have been suggested Licensee MDPI, Basel, Switzerland. to treat these hyperpigmentations, such as chemical ablation, hypopigmenting creams, This article is an open access article and surgery [5]. Lasers conventionally exploited to remove exophytic lesions, such as distributed under the terms and CO2 lasers, have been initially suggested using fractional modality to convey heat in the conditions of the Creative Commons superficial layers of the skin [6,7]. These devices are unfortunately linked with scarring Attribution (CC BY) license (https:// and hyper/hypopigmentations [8,9]. To avoid these side effects, lasers with shorter wave- creativecommons.org/licenses/by/ lengths, aiming to act exclusively on chromophores, achieve better cosmetic outcomes. 4.0/). Appl. Sci. 2021, 11, 7478. https://doi.org/10.3390/app11167478 https://www.mdpi.com/journal/applsci Appl. Sci. 2021, 11, x FOR PEER REVIEW 2 of 8 Appl. Sci. 2021, 11, 7478 layers of the skin [6,7]. These devices are unfortunately linked with scarring and hyper/hy-2 of 8 popigmentations [8,9]. To avoid these side effects, lasers with shorter wavelengths, aiming to act exclusively on chromophores, achieve better cosmetic outcomes. Among these la- sers, various papers suggest that the Q-switched laser, releasing energies in nano or pico- Among these lasers, various papers suggest that the Q-switched laser, releasing energies in second, acts selectively on melanin, and does not cause any thermal damage on the sur- nano or picosecond, acts selectively on melanin, and does not cause any thermal damage on therounding surrounding tissues. tissues. Picosecond Picosecond-pulsed-pulsed Q-switched Q-switched lasers lasers release release energy energy in in aa minimalminimal amountamount of of time time and and appear appear to to be be the the most most effective effective therapy therapy [ 10[10–12–12].]. ThisThis study study evaluates evaluates thethe safetysafety andand efficacyefficacy ofof hypermelanosis hypermelanosis removalremoval usingusing aa Q-Q- switchedswitched picosecond picosecond 1064/532 1064/532 nmnm laser.laser. 2.2. Materials Materials and and Methods Methods AllAll patients patients asking asking for for cosmetic cosmetic hypermelanosis hypermelanosis treatment treatment from from the the 1st 1st July July 2019 2019 to to thethe 30th 30th December December 2019 2019 at at the the dermatological dermatological department department of of Magna Magna Graecia Graecia University University (Catanzaro,(Catanzaro, Italy) Italy) were were retrospectively retrospectively recruited recruited in in this this study. study. Exclusion Exclusion criteria criteria included: included: hypersensitivityhypersensitivity toto lightlight (visible(visible andand near-infrared);near-infrared); medication known known to to increase increase sensi- sen- sitivitytivity to to light; light; therapies therapies with with anticoagulants anticoagulants and/or and/or immunosuppressants; immunosuppressants; pregnancy pregnancy or ornursing; nursing; personal personal or orfamily family history history of skin of skin cancer; cancer; sun exposure sun exposure in the in three the threeweeks weeks before beforetreatment treatment (for any (for skin any type); skin type); previous previous hyperpigmentation hyperpigmentation removal removal treatment; treatment; gold gold--con- containingtaining medication; medication; recent recent exfoliation exfoliation treatments, treatments, surgical surgical treatments treatments and past and skin past disor- skin disordersders (including (including keloids). keloids). ParticipantsParticipants werewere treated treated with with a a Q-switched Q-switched 1064/532 1064/532 nmnm laser laser system system (Pico, (Pico, Deka Deka M.E.L.A.,M.E.L.A., Calenzano, Calenzano, Italy)Italy) capablecapable ofof producing ultrashortultrashort pulsespulses toto reachreach selectiveselective pho- pho- tothermolysistothermolysis of of melanin melanin with with no no to to minimal minimal damage damage to neighboringto neighboring structures structures (Figure (Figure1) . Although1). Although variable variable and and dependent dependent on on the the region region of of interest, interest type, type of of melanosis, melanosis, and and skin skin 2 phototype,phototype, treatment treatment parameters parameters were were the the following: following: 1064 1064 nm, nm, up up to to 3 J/cm3 J/cm2with with a a pulse pulse 2 durationduration of of 450 450 picoseconds picoseconds (ps) (ps) for for dermic dermic lesions lesions and and 532 532 nm upnm toup 1 J/cmto 1 J/cmand2 and 370 ps370 for ps epidermalfor epidermal lesions. lesion Lasers. Laser sessions sessions were were performed performed at least at least 30 days 30 days apart apart or until or until complete com- recoveryplete recovery of the skin.of the The skin. final The evaluation final evaluation and follow-up and follow visit-up took visit place took threeplace monthsthree months after theafter last the procedure; last procedure; the clinical the clinical endpoint endpoint was the was complete the complete disappearance disappearance of the lesion(s).of the le- Allsion(s). patients All agreedpatients with agreed therisk with of the the risk procedure of the procedure and signed an informedd signed consent. informed The consent. study followedThe study the followed laser safety the laser guidelines safety ANSIguidelines Z136.3. ANSI Z136.3. FigureFigure 1. 1.Figure Figure of of the the Q-Switched Q-Switched system. system. BeforeBefore the the first first treatment treatment and and three three months months after after the the last last session, session, physicians physicians carried carried outout photographic photographic documentation. documentation. Researchers Researchers used used the the same same camera camera (Nikon (Nikon 5600d, 5600d, Nikon Ni- Corporation,kon Corporation, Minato Minato City, City, Tokyo, Tokyo, Japan) Japan) and and parameters, parameters, the the same