Green nail syndrome (GNS) is the most common bacterial infection of the nail unit.
Green nail syndrome (GNS) is the most common bacterial infection of the nail unit. Both the upper and lower extremities may be affected in GNS, but is uncommonly reported as a primary cause of onychodystrophy. The causative organism, Pseudomonas aeruginosa, is a gramnegative bacteria which is ubiquitous in nature favoring warm and moist environments with reservoirs in soil, water, plants and animals.
Infection of the nail results in chloronychia as a direct result of the production of pyoverdin and pyocyanin by P. aeruginosa.