Clinic Characteristics And Laser Therapy On Nevus Of Ota And Acquired Bilateral Nevus Of Ota-like Maculae

Nevus of Ota, synonymously termed nevus fuscoceruleus ophthalmomaxillaris,oculodermal melanosis, is a dermal hyperpigmentation along the first or second branches ofthe trigeminal nerve. Acquired bilateral nevus of Ota-like maculae（ABNOM） or nevusfuscoceruleus zygomaticus, Hori’ nevus, is bilateral, brown and blue-gray pigmentation overthe face. The sites involved include the forehead, malar area, temples, eyelids, root of the noseand ala nasi. Owing to lesions located on the face, Nevus of Ota and ABNOM often frustratesthe patients. In China, the incidence of Nevus of Ota is determined to be0.1-0.2%, and theincidence of ABNOM is approx to2.5%. The quantity of patients both Nevus of Ota andABNOM would be more than3million.Nevus of Ota and ABNOM usually affect colored race, are seen most commonly in Asiandescent. And both they show a marked preponderance in females, especially ABNOM. Nevusof Ota and ABNOM are clinically similar as they are speckled or confluent brownish-blue orslate gray over the face. Observed by light microscope, nevus of Ota and ABNOM are similar,that epidermis are normal, melanocytes gather in dermis. Melanocytes in Nevus of Ota arenumerous and distribute diffusely throughout the lower dermis. However, in ABNOM,melanocytes are dispersed in the upper dermis and more frequently in the perivascular area.Observed by electron microscope, melanocytes in Nevus of Ota contain many melanosomes（250～600nm）. In ABNOM, melanocytes contain the melanosomes with smallerdiameter(150～300nm) and smaller quantity. As to know, Nevus of Ota and ABNOM areclinically similar, but completely distinct.The pathogenesis is not precisely known, nevertheless it is hypothesized that theseaberrant pigmentations may be influenced hormonally by a mechanism with in thehypothalamic-pituitary-ovarian axis and genetic predisposition. And some hereditary factorswould increase the susceptivity. Recently, Many studies demonstrate that Endocrine disrupting chemicals (EDCs) increased in the environment. The clinical characteristics ofdisorders correlated with sex hormone have changed, however the studies about Nevus of Otaand ABNOM are rare. We invest the pathogenesis of Nevus of Ota and ABNOM, and inductthe clinical management.At present, Quality-switched laser systems have taken preference for clinical treatmentof pigmented lesions. Because the melanocytes scattered in the different portions of thedermis, melanosomes in different stages of melanization, the treatment effectiveness weredifferent. However, different responses can arise from different Quality-switched lasers anddifferent parameters. There has been very few control study in Nevus of Ota and ABNOMtreatment with Quality-switched laser. Systematicly analyze the issue, to conduct the clinictreatment.Study designIn order to conclude the clinic characteristics and therapy of Nevus of Ota and ABNOM,this research, composed with two parts, was carried out. During January,2006～January,2011, a total of434nevus of Ota patients and328ABNOM patients, which were confirmeddiagnosis of by plastic surgery center of Southwest Hospital affiliated to the Third militarymedical university, were retrospective analyzed, involved sex, age, age of onset, onset time,color, distribution and size of skin lesions, and so on, and compared the clinical characteristicsbetween Nevus of Ota and ABNOM. Subsequently, search the studies about the nevus of Otaand ABNOM Q-switched laser treatment in PubMed. To approach the preferred therapy, theclinical data including laser parameter, therapeutic effect, complications were systemicanalyzed.ResultsPart1: analyze clinic characteristics of Nevus of Ota and ABNOMCollective762patients,434cases clinical diagnosis Nevus of Ota and328cases clinicaldiagnosis ABNOM, mainly come from Chongqing(88.06%). As analyzed the cliniccharacteristics of these diseases such as sex, onset age, color, distribution, and so on, it wasdemonstrated as followed. Firstly, in males, the most acquired cases appear skin lesionsaround5.5years. However, the female display two peaks, one is before5, another is10～14years old. Secondly, clinic characteristics of Nevus of Ota are different in different periods.The percentage of acquired cases rises up gradually, and the onset age also increases. Thirdly, the onset age of ABNOM becomes an increased tendency.Part2Systemic analyze the effectiveness of Nevus of Ota and ABNOM after Quality-switchedlaser irradiationSearch the studies about the Nevus of Ota and ABNOM Quality-switched laser treatmentbefore December2011at PubMed, and30studies are included. After the systemic analysis,the results to approach the preferred therapy are illustrated as followed. Firstly, Nevus of Otais much more sensitive to Quality-switched laser than ABNOM. Secondly, different raceappear different effects of Quality-switched laser irradiation on the lesions. Thirdly, the laserparameters contribute to effect and complication. The treatment session, fluence, pulseduration are considered as key factors, and teatment interval, teatment end point, spot size andso on appear insignificantly. Fourthly, Quality-switched ruby laser (QSRL) is better thanQuality-switched alexandrite laser (QSAL) in treating Nevus of Ota and ABNOM.Additionally, Quality-switched neodymium:yttrium-aluminum-garnet laser (QSNYL) wouldbe more satisfactory, despite deficient evaluation about the effect of QSNYL.There is a treatment for information: treatment at the childhood, the acquired patientsshould take therapy quickly; the pulse duration should be no more than30ns; the fluencewould be less than10J/cm2; spot size should be in the scope of4～6.5mm and the teatmentinterval controlling in2month would be well.Conclusion1. Recently, clinic characteristics of Nevus of Ota and ABNOM have some changes.Considering with some changes of relevant diseases in the same area of sampling, EDCswould be the key point, which include these changes. Polycyclic aromatic hydrocarbons(PAHs) is the capital member of EDCs, and PAHs is able to modulate melanogenesis by theandrogen receptor (AR) and aryl hydrocarbon receptor (AHR) signaling pathways. This studyfocuses on the changes of clinic characteristics, in posed to approach the pathogenesis.2. This study analyzes the factors, which could effect the therapy results and suggest atreatment for information to conduct the clinic treatment.