Toenail Fungal Infection Treatment: What to Know

For the most part, toenails don't get much love. Sure, you trim them now and again, and maybe you even paint them bright in the summer. But toenails are one of the more uninteresting parts of our anatomy, and it's safe to assume hardly anybody even thinks about them—until there's a problem.

Like it or not, we spend our days living among various microorganisms, including fungi and yeast. Many of those organisms never make themselves known to us, peacefully coexisting in, on, and around our bodies. But some tend to overgrow, causing infection and many symptoms, from painless itching to funky odors.

That's what exactly happens when dealing with a bout of toenail fungus. Here's what you need to know about the different fungal toenail infections, what causes them, and how you can treat them.

What Is Toenail Fungus?

Toenail fungus, also called onychomycosis, is the umbrella term for a handful of microorganisms that can infect one or more of your toenails.

The infection is typically the result of a superficial cut, crack, or opening near your toenail. The fungus can sneak in and spread with this window of opportunity, causing an infection.

Infections can range from mild or barely noticeable to severe, affecting multiple toenails and causing pain or nail deformity.

Are There Different Types of Toenail Fungus?

There are three different types of toenail fungus, said William Spielfogel, DPM, a New York-based podiatrist, which include:

• Distal subungual: This is one of the most common types of toenail fungus, accounting for at least 60% of toenail infections, Ashley Jenkins, MD, a dermatologist at the University of Missouri Health Care, told Health. Distal subungual toenail fungus is caused by dermatophytes, which also cause athlete's foot, and only grow in keratin-producing structures like hair follicles and nails.
• White superficial: This is a non-dermatophyte that infects the top layer of the nail rather than the follicles.
• Candida: This is caused by yeast overgrowth. It's the least common type of toenail fungus. Still, some studies indicate it's becoming more common.
• Proximal subungual: This is caused by dermatophytes that infect the base of the nail and sometimes the top of the foot. It is more common in people with human immunodeficiency virus (HIV) than others.

What Does Toenail Fungus Look and Feel Like?

Any toenail fungus causes a range of symptoms, but some of the most common are:

• Nail thickening
• Yellowing, browning, or discoloration
• Nail crumbling
• Abnormal or frequent breakage
• Unusually shaped nails
• Separation of the nail from the nail bed
• Pain
• Odor or bad smell

Different types of infections often cause various symptoms. For example, many mold infections aren't painful, but yeast infections can be.

And you may notice a dark debris build-up under the nail with distal subungual toenail fungus. On the other hand, you're more likely to see white spots or patches on the nail's surface with white superficial toenail fungus.

What Causes Toenail Fungus?

We come into contact with yeast and molds that cause toenail fungus a lot, but there are several reasons why an infection might occur.

Typically, people with cracks in their toenails, or weakened ones, are most at risk. That includes older adults, people with superficial toe injuries, and people with certain skin conditions like psoriasis.

Dr. Jenkins said there are other common risk factors for toenail fungus, such as:

• Diabetes
• A history of athlete's foot
• A suppressed immune system, either because of an autoimmune condition (such as cancer or HIV) or immunosuppressant medicines and treatments (like chemotherapy)
• Nail infections, injuries, or recent surgeries
• A family history of nail infections
• Poor circulation
• Psoriasis

"If fungus is hanging around [under these circumstances], it will crawl underneath the nail and spread," explained Dr. Jenkins.

Additionally, some factors that may increase your risk for toenail fungus include:

• Wearing poor-fitting shoes
• Having poor circulation
• Sweating more than usual, especially from your feet
• Smoking
• Spending a lot of time in the water or walking in damp areas (like an indoor swimming pool)

How to Get Rid of Toenail Fungus

First, the bad news: Dr. Jenkins and Dr. Spielfogel said that toenail fungus is tough to treat, especially at home.

"The most effective treatment is an oral systemic antifungal medication, such as Lamisil [terbinafine], once per day for 12 weeks," explained Dr. Jenkins. "It cures around 75% of patients, but 25% won't be cured and will need repeat treatment or even a surgical treatment, like removing the toenail."

For the most part, Dr. Jenkins said Lamisil is safe for use, though it can, in rare cases, cause liver enzyme abnormalities. However, your healthcare provider will monitor those enzymes by performing regular blood work during your treatment. Dr. Jenkins added that the side effect is rarely seen in children.

And if you're concerned about Lamisil as a treatment option, or you have an existing medical condition that prevents you from safely taking it, your healthcare provider may prescribe a topical treatment. But those take much longer to work (as long as 48 weeks) than Lamisil.

Finally, you can try a home remedy for toenail fungus. While most aren't highly effective, they don't have many side effects. If your toenail fungus is mild, you can see results over time.

"[Home remedies] have maybe a 10% cure rate, but could be effective enough if someone is highly motivated," said Dr. Jenkins, adding that some patients prefer products like Vicks VapoRub, amber-colored Listerine, and tea tree oil.

And if you attempt an at-home remedy, you must give your toenail some extra care. 

"Keeping the area clean and dry may help keep the infection under control," noted Dr. Spielfogel.

Can You Prevent Toenail Fungus?

If your toenail fungus is caused by something in your control (such as an underlying condition), you can take steps to prevent it, including:

• Wear shoes in public areas, especially ones typically wet, like pools and gyms.
• Keep foot injuries clean and covered until they're healed.
• Protect your overall health by not smoking and maintaining a healthy weight.
• Wear supportive and breathable shoes.

You also may reduce bouts of toenail fungus by keeping your toenails consistently clean, dry, trimmed, and free of nail polish, which can contribute to fungal growth.

However, many causes of toenail fungus are caused by other factors, like age and chronic illnesses (like diabetes), which you cannot modify to prevent fungus.

Dr. Spielfogel recommended using preventative products if you know you're at risk for fungal infection. For example, Dr.'s Remedy line of nail care products includes an antifungal cuticle oil that you can use nightly to reduce the risk of fungus.

When Should You Visit a Healthcare Provider?

It's tempting to dismiss toenail fungus as an unsightly but mainly harmless problem. Like so many other health issues, though, ignoring it will only make things worse down the line.

"You should see a podiatrist [or dermatologost] when you notice the problem and treat it early," advised Dr. Spielfogel. "If left untreated, which is very common, the infection will spread to the rest of the nail and eventually spread to the other nails."

Once you make an appointment, your podiatrist will give your feet a thorough examination and may take a nail sample to be sent away for testing.

That will help your podiatrist confirm whether you have an infection and figure out precisely what type of infection you have, Dr. Spielfogel explained.

From there, your podiatrist can work with you on a treatment plan to (hopefully) get rid of your toenail fungus for good.

A Quick Review

Common microorganisms cause many types of toenail fungi. The fungus enters your toenails through damage or injury and spreads.

They're almost impossible to treat at home, but your healthcare provider can suggest some effective options. Additionally, you can prevent toenail fungal infections by keeping your feet clean and protected and being aware of any risk factors you may have.