Fingernail fungus, or onychomycosis, is a common infection affecting the nail bed and plate. It is primarily caused by microscopic fungi called dermatophytes, though molds and yeasts can also be responsible. This condition is contagious and can spread from person to person or from a surface to a person. An infected nail often shows discoloration, typically turning white or yellow-brown, and may become thickened, brittle, or crumble at the edges.
How the Fungus Spreads
Onychomycosis spreads through the transfer of microscopic fungal spores from an infected source to a new host. These spores are released by the active infection and can survive on various surfaces for extended periods. Contagion occurs through direct contact, such as touching an infected nail, or indirect contact with contaminated objects. Indirect spread is more common and involves sharing personal grooming items like nail clippers, files, or pumice stones that have not been properly disinfected. To establish an infection, the fungi must enter the nail unit through a microscopic breach in the skin or nail structure. A small cut, minor injury, or slight separation of the nail from the nail bed provides the necessary entry point.
Common Environments That Encourage Infection
Environmental Factors
Fungi thrive in conditions that are consistently warm, dark, and damp, making certain environments high-risk areas for exposure. Public spaces where people walk barefoot create a significant opportunity for transmission from contaminated floors. Locker rooms, community showers, and the decks around swimming pools are notorious breeding grounds for the organisms that cause nail fungus.
Host Susceptibility
Host factors play a large part in susceptibility, as not everyone exposed to the fungus will develop an infection. Individuals with underlying health conditions, such as diabetes or poor blood circulation, are more vulnerable because their body’s ability to fight off infection is reduced. Frequent exposure to moisture, such as from constantly wet hands or excessive sweating, softens the skin and nail, making it easier for the fungi to invade. Minor trauma to the nail, which can occur from ill-fitting shoes or aggressive manicures and pedicures, also increases the risk. Older adults are generally more susceptible due to reduced circulation.
Practical Steps for Limiting Transmission
Interrupting the cycle of transmission requires consistent hygiene and environmental awareness to minimize contact with fungal spores. In public, always wear protective footwear like shower sandals or flip-flops when using communal areas such as gyms, pools, and showers. This practice prevents direct contact between your skin and potentially contaminated surfaces.
Meticulous hygiene is essential for prevention and limiting spread:
- Thoroughly dry your skin after washing, especially the spaces between the toes and around the nails, as moisture encourages fungal growth.
- Avoid sharing personal items, including towels, socks, shoes, and all nail grooming tools, if you or a household member has an active infection.
- Disinfect any instruments used on an infected nail, such as clippers or files, after each use to prevent spreading the fungus.
- Wear clean, dry socks and change them frequently throughout the day to manage moisture.
- Keep nails trimmed short and clean to remove potential reservoirs where fungi can accumulate.
Treatment Options for Onychomycosis
Eradicating an established fungal nail infection stops the contagious cycle, though treatment is often lengthy due to the slow growth of the nail. For mild cases, topical antifungal medications, such as creams or medicated lacquers, may be prescribed. These treatments must be applied daily for several months, often six to twelve, to penetrate the hard nail plate and reach the infection site.
More severe or persistent infections typically require oral prescription antifungal medications, such as terbinafine. These drugs work systematically but necessitate a multi-month course, sometimes up to six months. A healthcare provider will perform blood tests before and during oral treatment to monitor liver function, as these medications can affect the organ.
If medication is ineffective or the nail is severely damaged, other medical interventions may be considered. These include laser therapy or, rarely, the temporary or permanent surgical removal of the infected nail. Consulting a healthcare professional is necessary for proper diagnosis and to determine the most appropriate treatment plan.