ABSTRACT
For twelve years,we have used liquid nitrogen in the treatment of Ota nevus (nevus fusco-caerule-us ophthalmomajillaris).Compared with the dry ice treatment,this method has the following adventages:(1) its very low temprature has a significant therapeutic effect and the number of treatment can be reduced to only half of what is needed in dry he treatment;(2) no apparent scar is left after treatment and depigmentation is rare.This method is also very effective for severe nevi that can not be cured by dry ice.Dermabrasion is used to remove melanosome of the epidermis and to facilitate the out-flow of exudate,therefore it is carried out at first superficially.At the same time,a special depi-lation needle with its half length covered by a silicone rubber sheath is used to destroy the remaining melanocytes under the skin.The skin impression taken after operation with dental synthetic rubber impression material shows the same skin furrows as those bf normal skin.This method is very effective in the treatment of Ota nevus.