Green Nail Syndrome

Green nail syndrome (GNS), also known as chloronychia, is a nail infection characterised by a green discoloration of the nail, most commonly caused by the bacterium Pseudomonas aeruginosa. It typically affects one or more fingernails or toenails and is associated with onycholysis (separation of the nail from the nail bed).

How It Occurs

Green nail syndrome occurs when Pseudomonas aeruginosa infects the space between the natural nail plate and the nail bed, especially when the nail is already damaged or lifted (onycholysis). The bacteria produce a green pigment called pyocyanin, which gives the nail its characteristic green color. This microorganism thrives in warm, moist environments – conditions that frequently develop beneath nail polish or within compromised nail structures.

Chloronychia is a bacterial infection affecting the nail plate. The critical distinction to understand is that despite common misconceptions, it is NOT a fungal infection.

Causes & Risk Factors

Nail Trauma Injuries or excessive manicuring can separate the nail plate from the nail bed, allowing bacterial colonisation. Moist environments, constant exposure to water (e.g., dishwashing, swimming) promotes bacterial growth. Wearing non-breathable footwear or gloves for extended periods.

Pre-existing Nail Conditions

• Onycholysis (nail separation)

• Nail psoriasis or fungal infections that damage the nail.

• Occupation-related Exposure. Common in people who work in: Healthcare Cleaning Food service Construction

• Immunocompromised States. Conditions like diabetes, HIV, or use of immunosuppressive medications.

Treatment Options

1. General Measures such as keeping nails dry and clean. Avoid prolonged exposure to moisture. Discontinue use of nail polish or artificial nails temporarily.

2. Topical Treatments. Topical antibiotics: Such as: Ciprofloxacin 0.3% drops (off-label use) or Gentamicin ointment (prescription). Acetic acid soaks (e.g., diluted vinegar): 1 part white vinegar to 4 parts water, soak for 5–10 minutes daily.

3. Systemic Antibiotics. Reserved for more severe or persistent cases. Prescription oral ciprofloxacin is commonly used due to its activity against Pseudomonas. May be necessary in immunocompromised patients or with extensive involvement.

4. Nail Debridement. Trimming and removal of detached portions of the nail can reduce bacterial load and improve treatment efficacy.

Address Underlying Causes

Treating onychomycosis if a coexisting fungal infection is present like candida or dermatophytes. It is also recommend to wear protective footwear if working in wet environments and drying agents for hyperhidrosis (excess sweating). Education on proper foot hygiene and avoiding prolonged moisture exposure is crucial.

Prevention & Follow-up

Use of breathable shoes and socks (e.g., moisture-wicking materials). Foot powders to reduce moisture such as Drital. Avoidance of trauma (e.g., trimming nails too short or tight footwear). Regular follow-ups to monitor regrowth and recurrence is also highly recommended.

If you or someone you know may be suffering with Green Nail Syndrome, feel free to click on the link below to book in your next appointment.

We look forward to helping you!