Help, My Nails Have Turned Green! What Is Chloronychia, AKA “Green Nail Syndrome”?

Take a quick peek down at your hands. Are your nails green? If so, there are a couple of possibilities: either you’re rocking a funky verdant manicure, in which case you'd probably remember that; or, it’s the much less pleasant option of green nail syndrome.

What causes green nail syndrome?

Technically known as chloronychia, and sometimes also as the Goldman-Fox syndrome, green nail syndrome, or the "greenies", the condition is caused by a nail infection that leads to a greenish tinge. You might see just a small patch, or it can be widespread over the whole nail, or multiple nails. It generally occurs alongside onycholysis, which is when the nail begins to separate from the nail bed underneath. 

The most common cause of green nail syndrome is the superbug bacterium Pseudomonas aeruginosa. Famed for hard-to-treat hospital infections, P. aeruginosa is often found in water, so people who do a lot of hand-washing – think healthcare workers, cleaners, and hair stylists – are most at risk from nail infections.

In rarer cases, green nail syndrome can be caused by fungi. Fungal nail infections in general are very common, especially in toenails, but they don’t normally cause a green appearance.

However, a 2021 case report discussed two patients with green nail syndrome that was found to be caused by the fungus Candida parapsilosis. To differentiate this from the usual bacterial version of the condition, the authors christened it “viridionychia”, as if we needed another unpronounceable word in this article. 

How is green nail syndrome treated?

“The best treatment is prevention,” write the authors of a 2020 letter to the editor of the journal Dermatologic Therapy, although they add that “there are a number of therapeutic options.”

If bacteria are to blame, one option is antibiotic eye drops – although not strictly intended for use on the nails, Dermatology Advisor explains that the formulation can help the antibiotic get into the different layers of the nail plate more effectively. Other topical antibiotics or antifungals may also be recommended depending on the type and severity of infection. 

Continuing the theme of treatments borrowed from other body parts, solutions of acetic acid – often found in ear drops to treat infections of the outer ear – can also be effective. In fact, one recent report detailed the case of a woman whose green nail syndrome followed a complex ear infection caused by P. aeruginosa – the authors suspected she had accidentally transferred some bacteria from her ear to her nail. 

Sometimes the nail may need to be removed if treatment is ineffective. In very rare cases, there could be a risk of the bacteria spreading to the rest of the body, but this is very unlikely unless the patient’s immune system is compromised. 

If you typically wear press-on nails, acrylics, or other enhancements, you will probably have to take a break from those while the infection clears up.

For most people, green nail syndrome can be treated quite easily – it just takes a long time, as anyone who’s ever tried to treat a fungal nail infection will know. In the case of one patient discussed in American Family Physician, topical antibiotics were required for four weeks. 

How to prevent green nail syndrome

If you work in a job that requires you to have your hands in water a lot, it’s tricky to completely eliminate the risk of green nail syndrome. The best thing you can do is ensure you’re drying your hands thoroughly each time you wash them. If you wear nail polish, it’s worth giving your nails a check each time you remove it, as you might be less likely to notice the early signs of discoloration that could indicate an infection. 

As well as occupational exposure to water, green nail syndrome is also made more likely by damage to the nail, either from trauma or from other conditions like psoriasis.

In general, if you’re worried about any change in the appearance of your nails, it’s best to seek medical advice. 

All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current. 

The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.