Korean J Dermatol.  2022 Aug;60(7):429-435.

Clinical Characteristics of Green Nail Syndrome: A Retrospective Analysis

• Lee GW
• Bae KN
• Son JH
• Shin K
• Kim HS
• Ko HC
• Kim B
• Kim MB

Abstract

Background
Green nail syndrome (GNS) is characterized by a greenish discoloration of the nail with accompanying nail apparatus disorders, such as onycholysis or paronychia. To date, data on the clinical characteristics of GNS are limited, especially in Korea.
Objective
This study aimed to investigate the clinical characteristics of GNS.
Methods
We retrospectively reviewed the medical records and clinical photographs of 78 patients with 91 GNS lesions diagnosed at the Pusan National University Hospitals (Busan and Yangsan) from 2009 to 2021.
Results
Among 78 patients, 47 (60.3%) were female and 31 male (39.7%), with a mean age of 53.1 years (23∼82 years). This study included 56 fingernail (61.5%) and 35 toenail lesions (38.5%). Thumbnails and great toenails were the most common site, with 62 lesions (68.1%). Most patients presented predisposing conditions, such as frequent exposure to wet conditions (55.1%), immunosuppressive conditions (26.9%), and trauma history (29.5%). The most common colors, shapes, and eccentricities of GNS were blackish-green (31.9%), reverse triangle (53.8%), and distal eccentricity (42.9%), respectively. The GNS was accompanied by various nail diseases that mostly (80.2%) preceded the syndrome, and onycholysis was the most common (83.5%). Based on the involvement of the nail surface or subsurface, GNS can be divided into the superficial (15.4%), subungual (73.6%), and mixed (11.0%) subtypes, each of which shows different clinical features, such as multiplicity, color, shape, and eccentricity.
Conclusion
This is the largest-scale study showing the clinical characteristics of GNS and can be helpful for dermatologists who usually and primarily treat GNS.

Keyword

Epidemiology; Green nail syndrome; Koreans