Recurrence of Nevus of Ota after Successful Laser Treatment: Possible Role of Dermal Stem Cells

Vol. 28, No. 5, 2016 647 Received July 22, 2015, Revised September 2, 2015, Accepted for publication September 7, 2015 Corresponding author: Hee Young Kang, Department of Dermatology, Ajou University School of Medicine, 164 WorldCup-ro, Yeongtong-gu, Suwon 16499, Korea. Tel: 82-31-219-5190, Fax: 82-31-219-5189, E-mail: [email protected] This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © The Korean Dermatological Association and The Korean Society for Investigative Dermatology biopsy (Fig. 2). At 5 months after treatment by surgical excision, the masses had not recurred. Foreign body reactions due to HA fillers can occur months or even years after injection. Therefore, a delayed foreign body reaction due to a HA filler is not easy to diagnose. Furthermore, a non-inflammatory, soft, subcutaneous lump distant from the filler injection site would not be considered a HA filler-related problem. Our patient had 2 sequential, bean-sized, flesh-colored, soft, subcutaneous masses on her face—one on the forehead and one on the glabella—after injection of a HA filler on the nose. She had not undergone filler injection on her forehead and glabella. This phenomenon can be explained by migration of the filler, which refers to the presence of filler at a location remote from the primary injection site. Filler migration can occur by several mechanisms, including poor injection technique (high-volume, high-pressure injection), massage, muscle activity, gravity, antigravity, pressure-induced displacement, lymphatic spread, and intravascular injection. According to a previous report, low-volume and low-pressure filler injections and more than 1 treatment session are recommended to minimize filler migration. Additionally, some authors suggest that patients with filler injections limit physical activity and keep the face at rest for the immediate time period after filler injection. We report a rare case of 2 sequential facial lumps related to the migration of injected filler. Dermatologists should be aware that dermal fillers, including HA fillers, can migrate to locations distant from the original injection sites.