Nevus of Ota: a new classification based on the response to laser treatment

For 60 years, Tanino's classification has been used to classify the extent of nevus of Ota. However, such classification not only fails to address variants such as phacomatosis pigmentovascularis but also cannot be used to predict the therapeutic outcome. Our objective is to retrospectively study our series of laser-treated patients with the aim of re-classifying nevus of Ota, so that such important issues can be taken into account.

One hundred nineteen patients that had received Q-switched laser treatment were recruited into the study. They were recalled for interview and examination for evidence of coexisting birthmarks and extracutaneous involvement. Two observers assessed the pre- and posttreatment clinical photographs for evidence of periorbital under-response (panda's sign), defined as the degree of periorbital laser clearing significantly less than clearing in the other area.

A total of 47.8% of the patients with periorbital pigmentation were considered by the observers to have significant periorbital under-response (panda's sign). Additionally, 10.1% had other birthmarks, and extracutaneous involvement was seen in 31.4% of the patients.

Periorbital under-response is commonly seen in patients with periorbital pigmentation. Taking this and other factors into consideration, we have proposed a new classification for nevus of Ota that allows for the prediction of the clinical outcome of laser treatment.