Pediatric Laser Therapy in Pigmented Conditions

Skin Pigmentation Types, Causes and Treatment-A Review

Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.

Laser treatment of benign melanocytic lesion: a review

Treatment of pigmented lesions is one of the major challenges of laser and cosmetic practitioners. The most common pigmented lesions that are treated by lasers are melanocytic nevi, ephelides, solar lentigines, and café au lait macules. Melanin absorbs different wavelengths (500-1100 nm); thereby, treatment of various pigmented lesions requires the application of lasers with different wavelengths. Choosing the most appropriate type of laser depends on various factors such as the chromophore and the location of a specific lesion in the skin. In this paper, we aim to review the most efficient laser treatment protocols for each pigmented skin lesion and compare their efficacy in each part based on the previous studies.

Efficacy and safety of picosecond 755-nm alexandrite laser for treatment of nevus of Ota in Taiwanese children: A retrospective study

OBJECTIVES

To evaluate the efficacy and safety of picosecond 755-nm alexandrite laser in the treatment of nevus of Ota in children.

MATERIALS AND METHODS

A retrospective study was conducted by reviewing medical charts and photographs of 86 Taiwanese children with various types of nevus of Ota between January 2017 and September 2020. Picosecond 755-nm alexandrite laser therapy was used to treat pigmentary lesions. Percent clearance of lesions during treatment and the treatment time required to achieve 95%-100% clearance were determined.

RESULTS

According to Tanino's classification or Peking University Medical College Hospital (PUMCH) classification of nevus of Ota, most patients belonged to Tanino's Type II (32%) and Type III (38%) or PUMCH Type IIb (33%) and Type IIIb (26%), which indicated that the nevus was mainly distributed in the forehead, upper and lower eyelid, zygomatic, cheek, and temple regions. After treatment with picosecond 755-nm alexandrite laser, 96.5% of the patients achieved 95%-100% clearance with an average of 4.3 treatment sessions. The earlier onset of lesions (before 5 months of age) and the darker Fitzpatrick skin types (type IV vs. type III) significantly increased the number of treatments required to achieve clear response, while sex, age at first treatment, Tanino's classification of nevus, and color of nevus had no significant effect. Posttreatment hypopigmentation or hyperpigmentation was transient and resolved within 6 months. No serious response of the skin was evident.

CONCLUSION

Picosecond 755-nm alexandrite laser treatment of nevus of Ota in children was safe and effective. The treatment was well-tolerated, and only a few transient, minor side effects occurred.

In vitro effects of photobiomodulation therapy on 50B11 sensory neurons: evaluation of cell metabolism, oxidative stress, mitochondrial membrane potential (MMP), and capsaicin-induced calcium flow

The analgesic properties of photobiomodulation therapy (PBMT) have been raising increasing interest in the clinical community due to the positive effects observed on patients, nevertheless the mechanistic basis of its action on peripheral sensory neurons remains still elusive. In this study, the effect of near-infrared (NIR) PBMT at 800 and 970 nm of wavelength was investigated on the 50B11 immortalized nociceptive sensory neuronal cell line by evaluating capsaicin-induced calcium flow and different markers correlated to mitochondria, that is, ATP, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP). Calcium peak stimulated by capsaicin, the ligand of TRPV1 channel, was decreased in neurons pre-irradiated with the combination of the two wavelengths. Furthermore, delivering the 800 and 970 nm separately an increment of ATP, as well as MMP hyperpolarization were detected; notably, the 800 nm wavelength also increased ROS and O₂^- levels. Our findings, obtained on an in vitro model of nociception, show the positive effect of PBMT on two potential photo-targets of NIR light, namely the TRPV1 channel and the mitochondria.