Green discoloration of the fingernails, medically known as chloronychia or green nail syndrome, can be a surprising sight. This condition typically presents as a greenish-yellow, greenish-brown, or even greenish-black hue on the nail plate. While the altered appearance might be alarming, it is often a localized issue rather than a sign of a deeper systemic problem.
The Main Culprit Behind the Color
The primary cause of green fingernails is the proliferation of a specific bacterium called Pseudomonas aeruginosa. This microorganism is commonly found in various natural environments, including water, soil, and other moist settings. It is an opportunistic bacterium, meaning it causes infection when conditions are favorable for its growth.
The distinctive green color results from pigments produced by Pseudomonas aeruginosa, such as pyocyanin (blue-green) and pyoverdin (yellow-green). These pigments accumulate on the underside of the nail plate, causing visible discoloration.
How Green Fingernails Develop
Several predisposing factors and environmental conditions allow Pseudomonas aeruginosa to colonize and thrive beneath the nail. Prolonged exposure to moisture is a significant contributor, common in individuals who frequently immerse their hands in water, such as those doing extensive dishwashing without gloves or engaging in water-related activities. A constantly damp environment fosters bacterial growth.
Minor injuries to the nail or nail bed also play a role by creating entry points for the bacteria. This can include trauma to the nail, a lifting of the nail plate from its bed (known as onycholysis), or even frequent manicures that might compromise the nail’s integrity. Artificial nails, if improperly applied or lifted, can trap moisture and debris, further facilitating bacterial growth.
Existing nail conditions can also increase susceptibility. Conditions like psoriasis or fungal nail infections (onychomycosis) can alter the nail structure, making it more vulnerable to bacterial colonization. While a weakened immune system can increase susceptibility, local environmental factors are usually the direct triggers for green nail syndrome.
What to Do About Green Fingernails
Managing green fingernails involves both preventative measures and targeted treatment strategies. To prevent the condition, it is helpful to keep nails consistently dry, especially after washing hands or showering. Wearing waterproof gloves for tasks involving prolonged water exposure, such as cleaning or dishwashing, can also be effective. Regular trimming of nails and maintaining good overall nail hygiene can further reduce the risk.
Some home-based approaches involve soaking the nail in a solution of diluted white vinegar (acetic acid) or a diluted chlorine bleach solution, 1 part vinegar to 4-10 parts water, for about 10 minutes twice daily. These solutions can help create an unfavorable environment for bacterial growth. It is important to ensure the nail is thoroughly dried after any soaking.
If the green discoloration persists, worsens, or is accompanied by pain or swelling, seeking professional medical advice is advisable. A doctor may prescribe topical antibiotic solutions or ointments, such as ciprofloxacin, gentamicin, or nadifloxacin, to directly target the bacterial infection. In some cases where topical treatments are insufficient, oral antibiotics might be considered. Occasionally, the affected portion of the nail may need to be trimmed or, in more severe instances, partially removed to facilitate healing.