What is a toenail infection?

A toenail infection can happen when a fungus grows on or in your toenail. It’s called onychomycosis. Toenail infections are common, especially in older people.

The skin around your toenail can also be infected. This is called paronychia. It’s usually caused by bacteria. But it can also be caused by herpes simplex (the virus that causes cold sores) or candida (a type of yeast).

What are the symptoms of toenail infection?

If you have a fungal nail infection, you might have:

• A yellow or brown nail
• white spots on your toenail
• a crumbling toenail when you cut it
• thickening of the nail
• the nail coming away from the nail bed (the skin under the nail)
• pain or a bad smell under your nail

Inflammation of the skin around the nail (called paronychia) usually happens quickly. You might have:

• a painful, red, swollen area of the skin next to your nail
• yellow pus under the skin
• the nail coming away from the nail bed
• painful blisters — if the infection is caused by the herpes simplex virus
• fever

What causes toenail infection?

Fungal toenail infections often happen when a fungal foot infection spreads. The most common fungal foot infection is tinea. Sometimes this is called ‘athlete’s foot’.

Fungi grow well in warm, moist places on the body. Feet are an ideal place for fungi to grow. You can catch tinea if your feet touch infected skin from another person.

You can also catch tinea from public pools and showers. This is because the tinea fungus from someone else’s foot can stay on these wet surfaces. Your feet can pick up the tinea from the wet floor.

You have more chance of getting a fungal nail infection if you:

• have sweaty feet
• wear closed shoes for long periods of time
• keep injuring your toenail
• have a health condition such as diabetes or a weakened immune system
• have a skin condition such as psoriasis

Paronychia

Bacteria can cause skin infections near the toenail. This is called paronychia. It often happens when there is damage to the skin near the toenail. The damaged skin lets the infection in.

Damage can happen from picking at your toenails or from an ingrown toenail. A pedicure can also damage the skin.

When should I see my doctor?

See your doctor if you have a toenail infection and treatment from the pharmacist. has not worked. You should also see a doctor if the infection has spread to other toenails.

If you get a fungal nail infection and have a weakened immune system or diabetes, you should also see a podiatrist.

How is toenail infection diagnosed?

Your doctor can scrape a sample from your toenail. The scraping will be sent for testing. It may take 5 to 6 weeks to get the results of the test. Once the test result is back, your doctor can choose the best treatment for you.

It’s important to wait for the test results before you start treatment. This is because other health conditions can cause similar symptoms. For example, a painful toenail can happen because of an injury to the nail. Toenail damage can also happen in people with long-term inflammation such as psoriasis.

How is toenail infection treated?

Most people need to take an oral antifungal medicine. This is medicine that you take by mouth. Treatment can take 3 to 6 months. It can sometimes take longer.

You may need to have blood tests while you are taking the medicine. These tests check that your liver is working properly.

Your nail might not look normal for several months after treatment. It can take months for a new healthy nail to grow.

Antifungal creams and ointments do not usually work well on toenail infections. Laser therapy is even less effective.

Sometimes it can be helpful to remove the infected nail.

The infection may come back after it has been treated. Your doctor or pharmacist might suggest that you use an antifungal cream or ointment. This can help to prevent the infection coming back.

Other important steps to take include:

• washing your socks and stockings in hot water
• cleaning your shoes with an antifungal spray
• letting your shoes dry out in the air — it’s best to switch pairs of shoes
• cleaning the floor of your shower or bath with bleach or disinfectant

If you have paronychia, your doctor may prescribe you an antibiotic or antiviral medicine. It can help to soak your toes in warm water several times a day.

What are the complications of toenail infection?

If the infection is not treated, your nail may become deformed or destroyed.

How can toenail infection be prevented?

You can help prevent getting toenail infection by:

• making sure your feet are clean and kept dry
• keeping your toenails short
• wearing clean cotton socks and changing them every day
• wearing shoes that fit well and let air flow in
• wearing footwear in public showers
• not sharing nail scissors or shoes

Your pharmacist can give you advice to help you prevent or manage your toenail infections.

Resources and support

Talk to your doctor or pharmacist if you have questions about a toenail infection.

The Australasian College of Dermatologists has information on nails, common nail problems and causes.

Read more about paronychia (nail fold infection) from DermNet.

You can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.