The most frequent pathogen causing bacterial nail infections is Pseudomonas aeruginosa, which produces a characteristic blue-green colour known as chloronychia. The clinical examination and dermoscopic results, as well as the diagnosis and therapy, have not been well studied. The goal of this study was to define the clinical and dermoscopic findings of P. aeruginosa infection of the nails and to evaluate therapeutic effectiveness. This is a retrospective analysis of individuals diagnosed with P. aeruginosa nail infection between January 27, 2017 and May 28, 2019. Twenty-six patients with P. aeruginosa nail infections were studied, with 21 finishing therapy, two lost to follow-up, and three continuing receiving treatment. In 76.9 percent of patients, clinical examination findings revealed onycholysis. Green discoloration was observed in 38.5 percent of patients, whereas green-brown discoloration was observed in 30.8 percent. The majority of patients only had one nail affected. Dermoscopic results for greenish pigmentation were significant in 37.5 percent of patients and 88.9 percent of instances with a fading border. Dermatopathology was more sensitive than wound cultures of nail plates, although the difference was not statistically significant. All patients were treated with ophthalmic 0.3 percent gentamicin topical solution nightly for three months, and those who finished therapy had their infection completely resolved.

Onycholysis with a green or green-brown discoloration encompassing one or more digits, as well as dermoscopic observations of greenish discoloration with a fading border, are compatible with a diagnosis of Pseudomonas nail infection. Gentamicin topical solution is an effective, low-cost, and simple to use therapy for this disease. To compare effectiveness with alternative treatment choices, larger randomised clinical studies are required.

Reference: https://link.springer.com/article/10.1007/s40257-019-00476-0