Green nail syndrome
Green nail syndrome is an infection that can develop in individuals whose hands are frequently submerged in water resulting in discolouration of the nails from shades of green to black. It may also occur as transverse green stripes that are ascribed to intermittent episodes of infection. It is usually caused by the bacteria Pseudomonas aeruginosa and is linked to hands being constantly moist or exposed to chemicals, or in individuals who have damaged or traumatised nails. There are several activities and nail injuries or conditions that are linked to higher risk of contracting the condition.
Symptoms and signs
Green nail syndrome is characterised by discolouration of the infected nail, inflammation of the skin around the nail known as paronychia, and an odour resembling fruit. The colour may range from light or blueish green or yellow-green to darker green or black. Nails may be separated from the nail bed and may have green stripes from repeated infections. Chronic fungal infection may also be present.Causes
Green nail syndrome is caused when the nail is exposed to a bacterial organism, which leads to opportunistic infection. Pseudomonas aeruginosa, the most common cause but not the only one, is frequently found in nature including in water sources, humans, animals and soil. These bacteria do not normally survive on dry, healthy skin, but can thrive in moist conditions. The seal between the nail and finger acts as a physical barrier to prevent infection, however hyper-hydration or destruction of the epidermis can impair the barrier, allowing the bacteria to colonise. The nail turns green due to the bacteria secreting pigments such as pyocyanin and pyoverdin.Risk factors
Green nail syndrome occurs rarely in healthy individuals, but can occur in the immunocompromised or those whose hands are frequently immersed in water or who have other nail problems. The elderly and people who have had trauma to a finger or nail are at greater risk of contracting green nail syndrome.Green nail syndrome has been linked to manicures, heat, dermatitis, ulcerations, occlusions and excess sweating. Higher risk of contracting the infection is also linked to soccer players and military personnel due to the prolonged periods of time in which they exercise while wear tight fitting shoes as well as immunosuppressed persons and those with a weakened epidermis barrier.
Pseudomonas can be transferred among clients in a nail salon if appropriate hygiene standards are not practiced, allowing transfer of the bacteria to clients. Artificial nails may be a contributing factor, and their use can result in diagnostic delay.
A man working in a job where he was regularly mixing chemicals developed green nails secondary to exposure to chemicals; he mostly wore latex gloves, but sometimes did not, and the type of gloves he used was inadequate, resulting in a constantly moist environment.
Cloronychia may be transferred to patients in clinics by medical practitioners, even when they are wearing gloves.