Tattoo removal by Q-switched Nd:YAG laser: an objective evaluation using histometry.

Background: Tattoos have played an important role in various human cultures for thousands of years. The creation of high power, short pulse Q-switched lasers (QS) has provided a tool for considerable therapeutic advances in tattoo removal. Objective: The aim of the study is to correlate the clinical efficacy of QS Nd: YAG laser for tattoo removal with histological as well as histometric findings. Patients and Methods: QS Nd: YAG laser was used for blue tattoo removal in 12 Egyptian patients. Sessions were done every 2 months for about 6-10 sessions (average 7). Skin phototypes of patients ranged from phototype III to V. Photographs were taken before and after every treatment session. Skin biopsies were taken from the patients before treatment and after six sessions to perform histological and histometric analysis. Results: Eight patients (66.7%) showed excellent response and four patients (33.3%) good response. No textural change or scarring was observed in any patient. Histological examination confirmed the clinical response. Haematoxylin and Eosin (H&E) stained sections showed a significant decrease or almost complete disappearance of the tattoo pigment. Meanwhile, histometric study objectively confirmed a significant decrease in ink particle surface area after treatment. Conclusion: QS Nd: YAG laser effectively treats tattoos in dark-skinned Egyptian patients with excellent cosmetic outcome and minimal side effects. The histopathologic and histometric findings significantly correlated with the clinical response.

Hair follicle changes following intense pulsed light axillary hair reduction: histometrical, histological and immunohistochemical evaluation.

Intense pulsed light (IPL) has been used for years in hair reduction; however, no previous studies discussed quantitative histological and immunohistochemical changes of hair follicles after IPL. Accordingly, this study aims to objectively quantify histological and immunohistochemical changes of hair follicles after IPL hair reduction. Right axillae of 21 volunteers were subjected to 6 IPL sessions using Quanta system IPL and evaluated at 1 week and 1 month after last session (i.e., 3 and 4 months from the start of treatment, respectively) in comparison to baseline and left control axillae. Using hair count, histological and immunohistochemical assessment of vertical and serial transverse sections coupled with computerized morphometric analysis, determination of hair reduction percentage, measurement of hair shaft (HS) diameter, calculation of percentage of hair follicle types and quantitative evaluation of PCNA, Ki67 and P53 markers were performed. After IPL, there was significant decrease of hair count, HS diameter, percentage of terminal anagen follicles, terminal/vellus (T/V) ratio, anagen/telogen (A/T) ratio and expression of PCNA and Ki67; however, significant increase of percentage of terminal telogen and total vellus follicles with vellus-like type and P53 expression was identified. So, reduction of hair number and thickness occurred after IPL by induction of telogenesis and miniaturization through decreased hair follicle proliferation and increase in DNA damage that could favor apoptosis.

Microdermabrasion: a clinical, histometric, and histopathologic study.

BACKGROUND: Microdermabrasion is a nonchemical superficial resurfacing procedure that removes the stratum corneum. Because it is a somewhat subtle procedure, it may be difficult to demonstrate its cosmetic benefit. OBJECTIVES: To assess the efficacy of microdermabrasion in treatment of melasma, postacne scarring, striae distensae, and photoaging by a series of microdermabrasion sittings through clinical, histometric, and histopathologic analysis. PATIENTS AND METHODS: The study was conducted on 38 patients constituting four groups (melasma, acne scars, striae destinsae, and photoaging), each patient was subjected to a series of 8 microdermabrasion treatments performed at 1-week interval. Punch biopsies, at base line, 1 week after the 4th and the 8th session, were obtained from each subject for histometric and histopathologic analysis. RESULTS: Clinically, the improvement in melasma, acne scars, and striae distensae groups was mainly mild to moderate, while in photoaging group was mainly mild. Histometric analysis of epidermal thickness showed insignificant changes in all groups. Histopathologically, decreased melanization and regular distribution of melanosomes in the epidermis were noted in melasma group while increased density of collagen fibers with more regular arrangement in collagen bundles was detected in all candidates of acne scars, striae distensae, and photoaging groups. Meanwhile, Orcein stain did not show any significant changes in elastic fibers. CONCLUSIONS: Microdermabrasion is an easy and safe technique. In this study, most cases showed mild to moderate improvement. Decreased melanization with regular distribution of melanosomes and increased collagen density with regular arrangement of collagen bundles were the most common observed histologic changes.

Forehead wrinkles: a histological and immunohistochemical evaluation.

BACKGROUND: Wrinkles are associated with cutaneous aging especially on sun-exposed skin. Despite they are considered a major topic in cosmetic dermatology, very few reports have studied the specific histological and immunohistochemical changes characteristic for wrinkles. AIM: The study aims to evaluate the histological and immunohistochemical changes of static forehead wrinkles in relation to surrounding photoaged skin. METHODS: Biopsy specimens were obtained from the forehead wrinkles of 20 volunteers of Glogau's class III-IV wrinkles. Using histological and immunostaining methods coupled with computerized morphometric analysis, measurement of epidermal thickness and quantitative evaluation of total elastin and tropoelastin as well as collagen types I, III, and VII were performed for skin biopsies. RESULTS: In the wrinkle site, there was statistically significant lower epidermal thickness (P = 0.001), elastin (P < 0.001), tropoelastin (P < 0.001), and collagen VII (P < 0.001) than the surrounding photoaged skin. Meanwhile, there was no significant difference between the wrinkle site and adjacent photoaged skin regarding collagen type I (P = 0.07) or III (P = 0.07). CONCLUSION: This study detected some histological and immunohistochemical differences in the wrinkle site when compared to adjacent photoaged skin. This may help in understanding the pathophysiology of facial wrinkling as well as its ideal way of management.

Fractional versus ablative erbium:yttrium-aluminum-garnet laser resurfacing for facial rejuvenation: an objective evaluation.

BACKGROUND: Laser is one of the main tools for skin resurfacing. Erbium:yttrium-aluminum-garnet (Er:YAG) was the second ablative laser, after carbon dioxide, emitting wavelength of 2940 nm. Fractional laser resurfacing has been developed to overcome the drawbacks of ablative lasers. OBJECTIVE: We aimed to objectively evaluate the histopathological and immunohistochemical effects of Er:YAG 2940-nm laser for facial rejuvenation (multiple sessions of fractional vs single session of ablative Er:YAG laser). METHODS: Facial resurfacing with single-session ablative Er:YAG laser was performed on 6 volunteers. Another 6 were resurfaced using fractional Er:YAG laser (4 sessions). Histopathological (hematoxylin-eosin, orcein, Masson trichrome, and picrosirius red stains) and immunohistochemical assessment for skin biopsy specimens were done before laser resurfacing and after 1 and 6 months. Histometry for epidermal thickness and quantitative assessment for neocollagen formation; collagen I, III, and VII; elastin; and tropoelastin were done for all skin biopsy specimens. RESULTS: Both lasers resulted in increased epidermal thickness. Dermal collagen showed increased neocollagen formation with increased concentration of collagen types I, III, and VII. Dermal elastic tissue studies revealed decreased elastin whereas tropoelastin concentration increased after laser resurfacing. Neither laser showed significant difference between their effects clinically and on dermal collagen. Changes in epidermal thickness, elastin, and tropoelastin were significantly more marked after ablative laser. LIMITATIONS: The small number of patients is a limitation, yet the results show significant improvement. CONCLUSION: Multiple sessions of fractional laser have comparable effects to a single session of ablative Er:YAG laser on dermal collagen but ablative laser has more effect on elastic tissue and epidermis.