The Difference Between Nail Mold and Nail Fungus

Anju Mobin
By Anju Mobin
Joel Taylor
Edited by Joel Taylor

Published April 30, 2022.

Fungal infection on a person's big toe

If there are white or yellow spots under your nail, it can very well be a fungal infection—but if the nail color is green, it may be a sign of nail mold. In fact, this nail color variation is used primarily for differentiating the two. However, the term "mold" generally denotes a fungus. Therefore, scientifically speaking, nail mold should fall under the umbrella term of "nail fungus."

Surprisingly, nail mold is not caused by any type of mold or fungi—recent studies have found that the causative agent for green nail discoloration is actually a type of bacteria called Pseudomonas, more commonly known as “greenies.”

Let's find out more about the differences between nail mold and nail fungus.

What Is Nail Fungus?

Nail fungus comes under the family of fungi. The most common cause of fungal nail infection are dermatophytes, yeast, and molds. Dermatophytes are fungi that require keratin for growth. Since nails are made up of keratin, they are prone to these fungal infections.

These fungi invade and consume the nail, leading to characteristic nail fungus symptoms. Also known as Onychomycosis, nail fungus usually starts with a spot on the nail and gradually results in the discoloration of the whole nail.

How fast it will spread depends upon the intensity of the infection. This is accompanied by thickening of the nails, pain, and a foul smell in some cases. Nails become brittle, chalky, and distorted in shape.

Fungus thrives in warm and moist conditions. When your nails come in contact with these infected surfaces, the fungus can enter through a cut or crack. They are contagious and the chances of getting them are very high in public places that are the hub of these fungi. Walking barefoot in common shower rooms of the gym or swimming pool is a recipe for disaster.

People who are most susceptible to nail fungus are old people, diabetics, people with poor blood circulation in the feet such as those with PVD, and immunocompromised people. The other risk factors are heavy sweating, a history of athlete’s foot, nail injury, and conditions like nail psoriasis.

What Is Nail Mold?

The bacteria that causes green nail syndrome (GNS) is Pseudomonas aeruginosa. It is one of the most prevalent pathogens of nail infection. It is characterized by green-black discoloration of the nail (greenish chromonychia) that is restricted to one or more nails (1).

People who have a history of prolonged exposure to water and detergents are likely to get nail mold.

Other causes include nail fungus (onychomycosis), nail disease in general, diabetes mellitus, immunosuppression, and paronychia (inflammation of the skin around the nails). Pseudomonas bacteria can also be transmitted from the infected site into a wound in the nail.

How to Diagnose Nail Fungus and Nail Mold

Both nail fungus and nail mold can be self-diagnosed by recognizing the symptoms.

To confirm whether the infection is fungal or bacterial, it is best to go to your doctor. He will perform a physical examination, take your history, and send your sample of pus, blood, or tissue to the lab for confirmation and diagnosis.

How to Treat Nail Fungus and Nail Mold

Nail fungus can be treated with various tried and tested home remedies. The effectiveness will depend upon the severity of the infection. Examples are iodine, essential oils, ozonated oils, Vicks Vaporub, and Snakeroot extract. These can be directly applied to the toenail. Epsom salt and apple cider vinegar foot are also very effective.

Popular over-the-counter medications such as Fungix are fast-acting treatments for nail fungus. It is due to their potent combination of natural ingredients that are strongly anti-fungal.

To treat GNS or nail mold, topical octenidine 0.1%, topical aminoglycoside, and nail extraction in severe cases are recommended. Another topical fluoroquinolone that has been approved to treat nail mold, as well as other skin infections, is Nadifloxacin (2). Even though it's an acne medicine, it has proved to be highly effective. Tobramycin is an antibiotic that is also given for treating nail mold (3).

Meanwhile, try and prevent the infections by following these given points.

  • Maintain a good hygiene
  • Keep your toes and fingers dry
  • Let them breathe
  • Do not wear used socks
  • Keep your shoes clean
  • Use shower shoes in the communal places
  • Clip your toenail and keep them clean
  • Choose breathable footwear

Should You See a Doctor for Nail Mold and Nail Fungus?

Home remedies can be very useful. If left untreated the nail can completely separate from your nail bed. It can become painful and disturb your quality of life.

However, in case things don’t work you should see a doctor for nail mold and nail fungus. This will help in proper diagnosis and the right treatment.

Natural medicines such as Fungix are very effective and the best overall choice.