Fungal Toe Nail Infections
This page is designed to provide comprehensive information on onychomycosis, a common fungal nail infection.
Onychomycosis is a fungal infection that affects the nails, typically on the toes but occasionally on the fingers as well. The condition is caused by various types of fungi, including dermatophytes, yeasts, and molds, which can invade the nail bed, matrix, or plate. Onychomycosis is more common in adults, particularly older individuals, and can lead to discolored, thickened, and brittle nails. It is essential to treat the infection, as it can cause pain, discomfort, and complications, especially in people with diabetes or weakened immune systems.
Onychomycosis is caused by fungi that thrive in warm, moist environments. Dermatophytes are the most common culprits, specifically Trichophyton rubrum and Trichophyton mentagrophytes. Other fungi, such as yeasts (Candida species) and non-dermatophyte molds, can also cause the infection. Factors that increase the risk of developing onychomycosis include age, a family history of the condition, athlete's foot, nail injury or deformity, moist environments, and medical conditions that weaken the immune system.
Symptoms of onychomycosis include nail discoloration (white, yellow, or brown), thickening or distortion of the nail, brittle or crumbly nails, and separation of the nail from the nail bed. The affected nails may also emit an unpleasant odor. In some cases, the infection can cause pain and discomfort, especially when wearing shoes or walking.
PAS (Periodic Acid-Schiff) staining, culture, and PCR (Polymerase Chain Reaction) testing are three laboratory methods used to diagnose onychomycosis.
PAS staining is a technique that uses a special stain to highlight fungal elements in nail samples. This method allows for the visualization of fungi under a microscope but does not identify the specific fungus responsible for the infection.
Culture involves placing the nail sample in a growth medium to encourage the growth of the causative fungus. This method can identify the specific fungus and help determine the most effective treatment. However, it may take weeks to obtain results, and some fungi may not grow well in culture.
PCR testing is a highly sensitive molecular technique that detects fungal DNA in the nail sample. It can quickly identify the specific fungus causing the infection. While PCR is more accurate and faster than other methods, it may not be widely available and can be more expensive.
Ignoring onychomycosis may result in several issues. The infection can lead to pain, discomfort, and walking difficulties, impacting everyday life and overall well-being. Thick and distorted nails can create challenges when wearing shoes or cutting the nails. In severe situations, the infection might spread to other nails, nearby skin, or different body parts. For those with diabetes or compromised immune systems, untreated onychomycosis increases the likelihood of secondary bacterial infections and foot ulcers.
A healthcare provider can diagnose onychomycosis by examining the affected nails and discussing the patient's medical history.
An accurate diagnosis requires identifying physical changes and conducting positive laboratory analysis. It is essential to consider other causes, such as psoriasis and chronic nail trauma, as only 50% of nail problems are caused by onychomycosis. Physical examination alone may be inaccurate. The lab tests can identify the specific fungus causing the infection, allowing for targeted treatment.
Laboratory testing involves examining nail clippings and debris from under the affected nail. Lab sites carry sample containers (a yellow envelope with black cardboard inside). You require a requisition from a physician to process the sample.
The area should be cleaned with 70% rubbing alcohol to avoid contamination. Samples should be gathered using a clean nail clipper or a small scraping tool. To increase accuracy, collect eight to ten small pieces of the nail.
Treating onychomycosis is time-consuming because nails, especially toenails, have a slow growth rate. Antifungal medications need to target the infected nail tissue while the nail grows out. This process may take months or even more than a year, depending on infection severity and individual nail growth. Adhering to the prescribed treatment plan and maintaining proper nail hygiene is essential for successful outcomes.
Several treatment options are available for onychomycosis, including oral antifungal drugs, topical antifungal solutions, and over-the-counter treatments. Oral antifungal medications like azoles and allylamines are highly effective and typically prescribed for moderate to severe infections. Topical treatments, such as nail lacquers or creams, are less potent but may be utilized for mild infections or alongside oral medications. Over-the-counter treatments, including tea tree oil or mentholated ointments, have limited proven effectiveness. In some instances, physical treatments like nail trimming, laser therapy, or permanent nail removal may be suggested.
Azoles and allylamines are two categories of antifungal drugs utilized for onychomycosis treatment. Azoles, like itraconazole and fluconazole, function by hindering ergosterol synthesis, an essential fungal cell membrane component. This action disrupts the cell membrane's stability, leading to fungal cell death. Allylamines, such as terbinafine, also target ergosterol synthesis but via a different mechanism. By blocking a specific enzyme (squalene epoxidase), allylamines cause a buildup of toxic substances within the fungal cell, resulting in cell death. Both azoles and allylamines effectively treat onychomycosis caused by dermatophytes and some non-dermatophyte fungi.
Oral antifungal drugs can cause side effects, although most are mild and temporary. Usual side effects encompass gastrointestinal issues (nausea, diarrhea, stomach pain), headache, and skin rash. In rare instances, these medications may lead to liver toxicity, necessitating regular liver function monitoring during treatment. Contraindications for oral antifungal drugs include liver disease, congestive heart failure, and specific drug interactions. Pregnant or breastfeeding individuals should also avoid these medications due to potential risks to the developing fetus or baby. It is crucial to share your medical background and any medications you are taking with your healthcare provider before starting oral antifungal therapy.
Apply Jublia directly to the infected toenail once a day, following the instructions provided by your healthcare provider or pharmacist. Make sure the nail and surrounding skin are clean and dry before application. Use the provided dropper to apply a thin layer of the solution, covering the entire nail, the skin around the nail, and the underside of the nail tip. Allow the solution to dry completely before putting on socks or shoes.
Treatment with Jublia typically takes several months, as healthy nails need time to grow and replace the infected nail material. Most patients see improvement within a few months, but the full course of treatment may last up to 48 weeks. It's essential to continue using Jublia as directed, even if the nail appears to be improving.
Common side effects of Jublia include irritation, redness, itching, swelling, and burning at the application site. These side effects are generally mild and resolve on their own. However, if you experience severe or persistent side effects, contact your healthcare provider. In rare cases, Jublia may cause an allergic reaction. If you notice symptoms such as difficulty breathing, hives, or swelling of the face, lips, or tongue, seek immediate medical attention.
Gupta AK, Stec N, Summerbell RC, Shear NH, Piguet V, Tosti A, Piraccini BM. Onychomycosis: a review. J Eur Acad Dermatol Venereol. 2020 Sep;34(9):1972-1990. doi: 10.1111/jdv.16394. Epub 2020 Jun 5. PMID: 32239567.
Rodgers P, Bassler M. Treating onychomycosis. Am Fam Physician. 2001 Feb 15;63(4):663-72, 677-8. Erratum in: Am Fam Physician 2001 Jun 1;63(11):2129. PMID: 11237081.
Frazier WT, Santiago-Delgado ZM, Stupka KC 2nd. Onychomycosis: Rapid Evidence Review. Am Fam Physician. 2021 Oct 1;104(4):359-367. PMID: 34652111.
Piraccini BM, Alessandrini A. Onychomycosis: A Review. Journal of Fungi. 2015; 1(1):30-43. https://doi.org/10.3390/jof1010030