Fungal infections can affect any part of the body. Fungi are normally present in and on the body alongside various bacteria. When a fungus begins to overgrow, you can get an infection.
Onychomycosis, also called tinea unguium, is a fungal infection that affects either the fingernails or toenails. Fungal infections normally develop over time, so any immediate difference in the way your nail looks or feels may be too subtle to notice at first.
A fungal nail infection occurs from the overgrowth of fungi in, under, or on the nail. Fungi thrive in warm, moist environments, so this type of environment can cause them to naturally overpopulate. The same fungi that cause jock itch, athlete’s foot, and ringworm can cause nail infections.
Fungi that are already present in or on your body can cause nail infections. If you have come in contact with someone else who has a fungal infection, it may have spread to you. According to the American Academy of Dermatology (AAD), fungal infections affect toenails more commonly than fingernails because your toes are usually confined to your shoes, where they’re in a warm, moist environment.
If you get a manicure or pedicure at a nail salon, be sure to ask how the staff disinfects their tools and how often they do it. Tools, such as emery boards and nail clippers, can spread fungal infections from person-to-person if they’re not sanitized.
There are many different causes of fungal nail infections, and each cause has a treatment of its own. Although many of the causes of a fungal nail infection are preventable, some risk factors increase the likelihood of developing it. You’re more likely to develop a fungal nail infection if you:
- have diabetes
- have a disease that causes poor circulation
- are over age 65
- wear artificial nails
- swim in a public swimming pool
- have a nail injury
- have a skin injury around the nail
- have moist fingers or toes for an extended time
- have a weakened immune system
- wear closed-toe shoes, such as tennis shoes or boots
Nail infections occur more often in men than in women, and the infections are found in adults more often than in children. If you have family members who often get these types of fungal infections, you’re more likely to get them as well. Older adults are at the highest risk for getting fungal infections of the nails because they have poorer circulation and their nails grow more slowly and thicken as they age.
A fungal infection of the nail may affect part of the nail, the entire nail, or several nails.
Visible signs of a fungal nail infection include:
- scaling under the nail, which is called subungual hyperkeratosis
- white or yellow streaks on the nail, which is called lateral onychomycosis
- a crumbling corner or tip of the nail, which is called distal onychomycosis
- flaking white areas on the nail’s surface, which may include pits in the nail
- the appearance of yellow spots at the bottom of the nail, which is called proximal onychomycosis
- loss of the nail
Common signs of a fungal nail infection include:
- a distorted nail that may lift off from the nail bed
- an odor coming from the infected nail
- a brittle or thickened nail
Because other infections can affect the nail and mimic symptoms of fungal nail infection, the only way to confirm a diagnosis is to see a doctor. They will take a scraping of the nail and look under a microscope for signs of a fungus. In some cases, your doctor may have to send the sample to a lab for analysis and identification.
Over-the-counter products aren’t usually recommended to treat nail infections because they don’t provide reliable results. Instead, your doctor may prescribe an oral antifungal medication, such as:
- terbinafine (Lamisil)
- itraconazole (Sporanox)
- fluconazole (Diflucan)
- griseofulvin (Gris-Peg)
You may use other antifungal treatments, such as antifungal nail lacquer or topical solutions. These treatments are brushed onto the nail in the same way that you would apply nail polish. Depending on the type of fungus causing the infection, as well as the extent of the infection, you may have to use these medications for several months. Topical solutions are not generally effective in curing toenail fungal infections.
Treatment isn’t guaranteed to rid your body of the fungal infection completely. In almost half of all cases, the fungal nail infection will return. Complications from fungal infection are also possible.
Making a few simple lifestyle changes can help prevent a fungal infection of the nails. Taking good care of your nails by keeping them well trimmed and clean is a good way to prevent infections. You should also avoid injuring the skin around your nails. If you’re going to have damp or wet hands for an extended amount of time, you may want to wear rubber gloves.
Other ways to prevent fungal infections of the nails include:
- using antifungal sprays or powders regularly
- washing your hands after touching infected nails
- drying your feet well after showering, especially between your toes
- getting manicures or pedicures from trustworthy salons
- using your own items for manicures or pedicures
- wearing socks that minimize moisture
- avoiding being barefoot in public places
- reducing your use of artificial nails and nail polish
For some people, a fungal infection of the nails can be difficult to cure and the first round of medication might not work. The nail infection can’t be considered cured until a new nail that’s free from infection has grown in. Although this indicates that the nail is no longer infected, it’s possible for the fungal infection to return. In severe cases, there may be permanent damage to your nail, and it may have to be removed.
The main complications of a fungal nail infection are:
- a resurgence of the infection
- a permanent loss of the affected nail
- a discoloration of the infected nail
- the spread of infection to other areas of the body and possibly the bloodstream
- the development of a bacterial skin infection called cellulitis
It’s especially important to see your doctor if you have diabetes and a fungal nail infection. People with diabetes are at greater risk of developing potentially serious complications caused by these infections. Talk to your doctor if you have diabetes and think you’re developing a fungal nail infection.