Toenail fungus, or onychomycosis, is a widespread fungal infection that affects the toenails. This common condition occurs when fungi penetrate the nail and grow beneath the nail plate. It can cause the nail to become discolored, thickened, and brittle. While not painful in its early stages, an untreated infection can spread and lead to discomfort or difficulty with walking. This condition affects a significant portion of the population, with estimates suggesting it impacts about 1 in 10 people overall.
Is Candida a Cause of Toenail Fungus?
Candida species, particularly Candida albicans, can cause toenail fungus, a condition referred to as candidal onychomycosis. Candida is a type of yeast, a natural part of the human body’s microbiome, commonly found on skin and mucous membranes. However, it is a less frequent cause of toenail infections compared to other types of fungi.
Infections caused by Candida often occur when the nail has been damaged by injury or another infection, creating an entry point for the yeast. Individuals with weakened immune systems, those who frequently immerse their hands or feet in water, or people with certain underlying health conditions may also be more susceptible. When Candida infects the nail, the area around the nail may become swollen and inflamed, and the nail itself can become discolored or even detach.
What Primarily Causes Toenail Fungus?
The most common culprits behind toenail fungus are dermatophytes, a group of molds that thrive on keratin, the protein found in nails, skin, and hair. These fungi are responsible for approximately 90% of all toenail fungal infections. The predominant species among dermatophytes causing onychomycosis is Trichophyton rubrum. Dermatophytes are acquired from contaminated surfaces in public, damp environments such as swimming pools, locker rooms, and showers. Once established, they feed on the keratin in the nail.
How Toenail Fungus is Diagnosed
Accurately diagnosing toenail fungus requires more than just a visual examination. The appearance of an infected nail can be similar across different fungal types or even resemble other nail conditions, requiring laboratory confirmation.
A healthcare provider will begin with a clinical examination, assessing the nail’s appearance, including any changes in shape. To determine the exact cause, a sample of the nail—usually clippings or scrapings from the affected area—is collected. This sample is sent for laboratory analysis.
One common initial test is a potassium hydroxide (KOH) wet mount, where the nail material is treated with KOH to dissolve keratin, allowing for microscopic visualization of fungal elements. However, a fungal culture is often performed to grow and identify the specific species of fungus, such as Candida or Trichophyton rubrum, which is important for guiding targeted treatment.
More advanced methods like Polymerase Chain Reaction (PCR) testing can be used for rapid and sensitive detection of fungal DNA. Professional diagnosis is important to ensure effective treatment and avoid self-treating conditions that may not be fungal.
Treatment and Prevention
Treatment for toenail fungus varies depending on the type of fungus identified and the severity of the infection. For milder cases, topical antifungal medications applied directly to the nail may be prescribed. However, for more severe or persistent infections, oral antifungal medications are often necessary, as they can reach the fungus more effectively through the bloodstream. These oral treatments require a commitment of several months, and potential side effects are discussed with a healthcare provider.
Other treatment modalities include laser therapy, which can help eradicate the infection, and temporary or permanent removal of the infected nail may be considered. It is important to note that Candida infections may respond differently to treatments than those caused by dermatophytes, further emphasizing the need for accurate diagnosis.
Preventing toenail fungus involves maintaining good foot hygiene, regularly washing and thoroughly drying feet. Wearing breathable footwear and moisture-wicking socks can help keep feet dry, as fungi thrive in damp environments.
Avoiding walking barefoot in public areas like locker rooms and showers, where fungi are prevalent, is also an important preventive measure. Regularly inspecting nails for any changes and addressing them promptly can help prevent infections from becoming severe.