Factors affecting response, number of laser sessions and complications in nevus of Ota treated by Q-switched alexandrite laser: a retrospective study.
BACKGROUND
The aim of this study was to study and analyze the factors influencing the treatment response to Q-switched alexandrite laser in patients with nevus of Ota and the factors influencing the number of laser sessions.


METHODS
Forty-eight patients treated with Q-switched alexandrite between 2009 and 2013 for nevus of Ota were enrolled in this retrospective, single-center study. The subjects (13 male, 35 female) were divided into three groups according to the number of treatment sessions. Patients were then called back to the hospital for a follow-up interview and examination. Single and multiple variate analyses of various factors were performed.


RESULTS
The 48 patients were predominantly female (35 female, 13 male, F:M ratio = 2.7:1), mean age 17.2±10.41. Twenty-five (52.1%) had lesion on the right side of the face, 22 (45.8%) on the left side, and one (2.1%) on both sides. The predominant color was brown (41.7%), followed by cyan (39.6%) and lividity (18.8%). Satisfactory result was observed in all patients, after 3 to 11 treatment sessions (mean 5.37±2); 19 of these (39.6%) needed three to four sessions (short treatment sessions), 22 (45.8%) needed five to seven sessions (intermediate treatment sessions), and 7 (14.6%) needed nine to eleven sessions (long treatment sessions). The clinical response and treatment sessions of the young-age group were significantly better than the adult group. Those with higher Tanino's classification needed more treatment sessions. Dark-colored lesions, which reflect deep melanosis of the lesion, needed more sessions than lighter-colored lesions. As for skin color, better response was obtained in light-skinned patients than in dark-skinned ones. Two patients showed transient hypopigmentation that lasted for less than six months, and recurrence has been seen in one child with dark-colored lesion.


CONCLUSIONS
Q-switched alexandrite laser is an ideal minimally-invasive method for treating nevus of Ota. Fewer treatment sessions are needed for children and younger patients, whereas brown lesion, lower Tanino's classification and light skin patients.
Department of Dermatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China - hcz0501@126.com.
Loai
L
Sami
Huang
H
Changzheng
Li
L
Yan
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005153:Facial Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017496:Hypopigmentation / Q000209:etiology; D007223:Infant; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008297:Male; D008548:Melanosis / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009507:Nevus of Ota / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology / Q000601:surgery*; D012880:Skin Pigmentation; D016896:Treatment Outcome; D055815:Young Adult