A 3-year-old boy presented with bluish patch and scattered blue spots on the left side of his face. After several sessions of laser treatment, the azury patch in the periorbital area became even darker. Histopathology showed many bipolar, pigment-laden dendritic cells scattered in the papillary and upper reticular dermis. Immunohistochemically, these cells were positive for S100, SOX-10, melan-A, P16, and HMB-45. The positive rate of Ki-67 was less than 5%. Finally, the lesion was diagnosed with nevus of Ota concurrent with common blue nevus. Therefore, for cases of the nevus of Ota with poor response to laser treatment, the possible coexisting diseases should be suspected.
Male ; Humans ; Child, Preschool ; Nevus, Blue/pathology* ; Nevus of Ota/therapy* ; Skin/pathology* ; Face ; Skin Neoplasms/pathology*

The evaluation of pigmentary skin lesions by clinical doctors has been based on subjective and qualitative judgements. Observations have mostly relied on visual inspection, making the effects of treatment difficult to evaluate with any precision. For this reason there is a real need for an objective method to evaluate prognosis after treatment. Recent scientific measurements such as reflectance spectrophotometry and reflectance colorimetry have provided accurate quantitative color information about skin lesions, but these techniques are costly and difficult to apply in the clinical field. The purpose of this study was to develop a simple and cost-effective way of evaluating treatment results. We have developed a software program using the L*a*b* color coordinate system to quantify the effect of treatment and have successfully demonstrated its clinical usefulness. Our method compares the relative color difference between normal skin and skin lesions before and after treatment, instead of measuring the absolute color of skin lesions. The accuracy of our quantitative color analysis was confirmed by the simulated images of hemangioma and ota nevus. Clinical efficacy was also confirmed through a blind test involving 3 clinicians who were asked to grade the treatment effects of 13 cases of hemangioma and 7 cases of ota nevus. These subjective clinical grades correlated well with the treatment results obtained using the proposed color analysis system (Correlation coefficient = 0.84).
Color* ; Female ; Hemangioma/therapy ; Hemangioma/pathology ; Human ; Nevus of Ota/therapy ; Nevus of Ota/pathology ; Outcome Assessment (Health Care)/methods* ; Pigmentation Disorders/therapy* ; Pigmentation Disorders/pathology* ; Skin Neoplasms/therapy ; Skin Neoplasms/pathology ; Skin Pigmentation* ; Software*

Both acquired bilateral nevus of Ota-like macules (ABNOM) and nevus of Ota are characterized by the presence of dermal melanocytes. There are no differences in the method of treatment, however, postinflammatory hyperpigmentation (PIH) develops more often in ABNOM than in nevus of Ota following treatment. We investigated the differences in the development of PIH after treatment between ABNOM and nevus of Ota, and the histopathologic differences in the PIH. A total of 82 patients with ABNOM (n=47) and nevus of Ota (n=35) were treated with Q-switched alexandrite laser and followed up 2 weeks and 3 months later. Biopsies were performed on lesional skin before treatment. The distribution and the amount of melanin pigments were visualized with Fontana-Masson stain, and the distribution and the depth of melanocytes were measured by GP-100 (NK1-beteb) stain. Clinically, there was more erythema and PIH in ABNOM than in nevus of Ota. Histopathologically, intradermal melanocytes were clustered in groups and dispersed perivascularly in ABNOM, while melanocytes were scattered evenly throughout the dermis in nevus of Ota. Both groups show that when there is a statistically significant number of melanocytes in the perivascular area, erythema and PIH occur after laser therapy. In conclusion, indirect vessel injury in addition to perivascular clustering melanocytes might be considered the cause of increased PIH after treatment in ABNOM.
Adolescent ; Adult ; Child ; Child, Preschool ; Comparative Study ; Humans ; Hyperpigmentation/*pathology ; Laser Therapy, Low-Level ; Melanocytes/*chemistry/cytology ; Middle Aged ; *Nevus of Ota/pathology/therapy ; *Nevus, Pigmented/pathology/therapy ; Silver Nitrate ; *Skin Neoplasms/pathology/therapy ; Treatment Outcome

OBJECTIVETo investigate injury to epidermal melanocyte by Q-switched Alexandrite laser.

METHODSMultiple biopsies were performed on 5 patients with nevus of Ota from before irradiation to 1 year after irradiation. Fourteen specimens were obtained for light microscopy, and 17 for transmission electron microscopy.

RESULTSMelanosomes in epidermal melanocytes were both smaller in size and fewer in number than those in dermal melanocytes. Immediately after irradiation, focal extracellular vacuoles of the basal layer could be observed under light microscopy. Most epidermal melanocytes underwent mild or moderate injury in the form of vacuolated melanosomes, swollen mitochondria, dilation of endoplasmic reticulum, and expansion of extracellular space, retaining intact cell membranes. Normal structures were restored 5 months to 1 year after irradiation, with no depigmentation or hyperpigmentation as seen by light microscopy.

CONCLUSIONInjury of melanosomes in epidermal melanocytes is reversible.

Adolescent ; Adult ; Beryllium ; therapeutic use ; Female ; Humans ; Laser Therapy ; Lasers ; adverse effects ; Melanocytes ; radiation effects ; Microscopy, Electron ; Nevus of Ota ; pathology ; radiotherapy ; ultrastructure ; Skin Neoplasms ; pathology ; radiotherapy ; ultrastructure

OBJECTIVETo evaluate the clinical response of Nevus of Ota to Q-switched Alexandrite laser, and analyze factors that influence the treatment outcome.

METHODSA total of 522 patients treated with Q-switched Alexandrite laser were included in the study. Single and multiple variate analyses of various factors were performed.

RESULTSSatisfactory result was observed in all patients, none of whom developed scarring. Clinical response was improved with additional treatment sessions. The clinical response of the 20 - 27-week treatment interval group was significantly better than that of the 12 - 19-week interval group, but showed no significant difference as compared with both the 28 - 35 and > or = 36-week interval group. Zygomatic, buccal and frontal areas showed better response than ocular and temporal areas. Treatment session, interval, and fluence were significant factors identified by multivariate analysis.

CONCLUSIONSQ-switched Alexandrite laser is an ideal method for treating Nevus of Ota without injury. The number of treatment sessions is more important than interval or fluence.

Adolescent ; Adult ; Child ; Child, Preschool ; Facial Neoplasms ; pathology ; surgery ; Female ; Humans ; Infant ; Laser Therapy ; adverse effects ; methods ; Male ; Middle Aged ; Nevus of Ota ; pathology ; surgery ; Pigmentation Disorders ; etiology ; Skin Neoplasms ; pathology ; surgery