Green nail syndrome is a nail problem also known as chloronychia or under the acronym GNS. It is an infection that causes nails to lose their normal color and become green, just as the name suggests. The exact color is actually variable, from a dark green to a bluish green or even one between blue and grey. The color can't be removed by rubbing or washing the area, since it is actually located under the nail. It can affect the nails on both the fingers and the toes but only one or two nails are usually infected. The cuticle and other skin areas around the nail can be inflamed but the nail itself is rarely painful.
The cause of the infection behind green nail syndrome is the Pseudomonas aeruginosa bacteria. It inhabits many wet locations, such as sinks, Jacuzzis, bath sponges and even contact lens solutions. As part of its normal development cycle, the bacteria produce pyocyanin and pyoverdin, two pigments with a green color. These are the root cause of the discoloration associated with the green nails syndrome.
As already mentioned, the main cause of the green nails syndrome is an infection with the bacteria Pseudomonas aeruginosa. However, the infection can also be triggered by a different pathogen, Aspergillus. Both of these bacteria colonize the space between the nail and its bed, where they produce the distinctive pigments that lead to the green color. Some professions, like bartenders, bakers or beauticians, have a higher risk to develop this condition. Women who often use detergents or water with soap are also more likely to be infected. Using artificial nails or dirty nail care tools are other possible causes, as well as a disease known as onycholysis.
The pseudomonas bacteria are actually quite common and inhabit most homes. It lives in water, soil, plants, as well as on pets. Normal nails can't be infested by this bacterium. However, if a nail or nail plate is injured, the pathogen can enter and use it as a host. The bacteria start to consume the dead tissues inside the nail plate, which eventually causes the nail and the nail bed to detach and become separated. The bacteria in the nail bed produce two types of green pigments that cause the distinctive color of this condition. Other symptoms of infection are pain and the nail can become thicker than normal, with fragile edges.
Another possible cause of green nails is onychomycosis, although this is an uncommon effect. Onychomycosis is an infection with a fungus that rarely affects youngsters but the risk increases with age. Green nails can also appear due to onycholysis, if a nail detaches from its nail bed. There are multiple events that can cause it, such as injury during manicure, repeated nail damage or even long periods of immersion in water. If none of these causes can be identified, a doctor will usually check for thyroid diseases, skin problems or other issues.
There are two conditions known to greatly increase the risk of green nails. Onycholysis, or a loose nail that separates from its nail bed, is a major risk factor. As long as the nail is well connected to the skin, this creates a waterproof protection layer. However, if the nail gets detached, the protection is lost and the space under it becomes full of dirt, creating an environment where bacteria can grow and reproduce. Nails often detach due to repeated trauma and people who do repetitive manual labor have a higher risk to experience this problem. Gardeners, janitors or plumbers are particularly exposed.
Wet environments are also a major risk factor for green nails. Pseudomonas aeruginosa likes damp locations and rarely infects the skin if it remains dry. However, nails that are often wet or immersed provide it with ideal conditions. Because of this factor, people who work as cooks, dishwashers or health care professionals have a higher risk of GNS, as well as housewives. A damp environment for the toenails can also result from exercising in tight shoes or just wearing them for a long time, like in the case of football players and military conscripts. Nail psoriasis and fungal infestations are other known risk factors.
Green nails are usually very easy to diagnose due to their trademark color. Dermatologists can also cut a nail sample for culture, if there is any doubt.
Artificial nails are another common cause of the green nail syndrome, due to hygiene issues. It is very important to clean the nail surface and disinfect it before applying a fake nail on it. Since the pseudomonas bacteria are widespread, they can already be present on the nail and can quickly multiply in the environment without oxygen created under the artificial nail. The green color is just a side effect of the bacteria consuming the oils and dead tissues.
This condition is usually treated by applying a local antibiotic on the affected area. Make sure that your nails are cut short in order to allow the active agents to reach the infection easily. Two or three weeks of treatment are normally required until the color of nails is restored.
Tea tree oil and other natural products with antiseptic properties can also be used as an alternative. A big advantage of tea tree oil is that it kills both bacteria and fungi, so it can counter both possible causes for green nails. You can also soak your nails in alcohol several times per day in order to kill the bacteria. A simple precaution is to always wear gloves when you immerse your hands in water.
Green nail syndrome is not a serious condition and treatments are usually effective. Try to avoid injuring the affected area, keep your nails dry and cut off any detached nails. Bacitracin, polymyxin B and other antibiotics will cure green nails after a few months if applied topically one or more times every day. Preparing a solution of diluted chlorine bleach, with a ratio of about 1 to 4, can also prevent the bacteria from expanding further. Another effective counter for topical applications is acetic acid, widely available as vinegar. If all of these treatments fail, in rare cases it might be required to remove the nail completely. In severe situations, your doctor can prescribe stronger oral antibiotics like ciprofloxacin.