Onychomycosis is the medical term for a fungal infection of the nail, which can affect the nail plate, nail bed, or nail matrix. Dermatologists are specialists in skin, hair, and nails who possess the expertise to accurately diagnose and manage these infections. Seeking care from a dermatologist ensures access to prescription-strength treatments tailored to the specific severity and type of infection.
Confirming the Diagnosis
A visual inspection alone is insufficient for diagnosis, as conditions like nail psoriasis or trauma can mimic a fungal infection. The dermatologist must confirm the presence of fungus before initiating any lengthy treatment. This initial step involves taking a small sample from the nail, often a clipping or scraping of the debris underneath the nail plate.
The most common diagnostic procedure is a potassium hydroxide (KOH) preparation. In this test, the sample is dissolved in a KOH solution to break down keratin, allowing fungal elements to be visualized under a microscope. While the KOH test offers quick results, it cannot identify the exact species of fungus causing the infection. For precise identification, the sample may be sent for a fungal culture or for polymerase chain reaction (PCR) testing. PCR testing is a rapid molecular method that detects fungal DNA, providing definitive identification of the pathogen to guide targeted treatment.
Comprehensive Treatment Options
Treatment is multifaceted, based on the infection’s severity and the patient’s overall health. For mild to moderate infections, or when oral medications are contraindicated, topical antifungal agents are the first-line approach. These prescription-strength treatments include medicated lacquers and solutions, such as ciclopirox, efinaconazole, and tavaborole.
These topical solutions must be applied daily for an extended period, penetrating the nail plate to reach the infection site. Topical treatments have minimal side effects, usually limited to local irritation. However, they are generally less effective than systemic options due to poor penetration, especially in thick or severely affected nails. For widespread or severe infections, oral antifungal medications are considered the gold standard due to their higher efficacy and shorter treatment duration.
The most commonly prescribed oral medication is terbinafine, which achieves a high cure rate by accumulating in the nail bed. Another option is itraconazole, often administered in pulse-dosing regimens. Since these oral drugs are absorbed systemically, the dermatologist requires baseline blood tests to monitor liver function before and during treatment. For cases resistant to medication or involving significant nail damage, procedural options may be employed. These include laser therapy, which uses focused light to target the fungus, or surgical nail removal.
Treatment Duration and Preventing Re-Infection
Treatment Duration
The duration of treatment is dictated by the slow rate of nail growth, not just the time required to eliminate the fungus. The new, healthy nail must grow out fully to replace the damaged nail plate, even after the fungus is cleared. This process typically takes six weeks for fingernails but requires six to twelve months or longer for toenails to be successful.
Patients taking oral antifungals like terbinafine typically complete a 12-week course for toenails. However, the full cosmetic result is not visible until the entire nail has regrown.
Preventing Re-Infection
Preventing re-infection is a long-term strategy, as recurrence rates are significant. Dermatologists emphasize meticulous foot hygiene, including thoroughly drying the feet, especially between the toes. This practice avoids creating a moist environment conducive to fungal growth.
Wearing clean, breathable footwear and changing socks frequently helps manage moisture levels. Simple practices like wearing shower shoes in public areas, such as gym locker rooms and pools, reduce the risk of picking up fungal spores. Some dermatologists may also recommend the prophylactic use of topical antifungal solutions after the infection is cleared to minimize recurrence.