What is a fungal nail infection?
The human body harbors a variety of microorganisms, including fungi. Although these fungi normally live on and within our skin without causing harm, an overgrowth can lead to infection. When this overgrowth occurs in the area of the fingernails or toenails, it’s called a fungal nail infection. Also known as onychomycosis or tinea unguium, these infections affect roughly 2–8 % of the population1. The likelihood rises with age, reaching up to 50 % in those over 70 years old2.
What causes nail infections?
Fungal nail infections develop when fungi proliferate on, beneath, or inside the nail plate. Dermatophytes are the most frequent culprits, but yeasts and molds can also cause these infections3. Injuries or breaks in the nail allow fungal organisms to penetrate and establish an infection. Transmission can also occur from existing skin conditions such as athlete’s foot. Fungi thrive in warm, moist settings, walking barefoot in communal areas like locker rooms, pools, or showers, or sharing footwear, greatly increases risk. Tight, enclosed shoes trap moisture and warmth, which is why toenails are more commonly affected than fingernails.
Signs and symptoms of fungal nail infections
Common indicators include4:
- White or yellowish streaks or spots beneath the nail tip
- Nails that have become thickened or coarse
- Edges of the nail that crumble, split, or become brittle
- Nail discoloration (white, yellow, or brown)
- Nail detachment from its bed
- Tenderness or pain around the nail
- An unpleasant odor from the affected nail
Risk factors
While anyone can develop a fungal nail infection, certain factors elevate the risk:
- Advancing age, which can lead to brittle nails and impaired circulation
- Male gender, as men experience infections more often than women
- Diabetes mellitus
- Reduced peripheral blood flow
- Immune system deficiencies
- Previous episodes of athlete’s foot
- Walking barefoot in communal spaces (showers, changing rooms, pools)
- Minor trauma to the nail or surrounding skin
- Prolonged moisture exposure on fingers or toes (e.g. athletes, kitchen staff, cleaners)
- Use of artificial nails
- Wearing non-breathable, closed footwear like boots or athletic shoes
- Patronizing nail salons with inadequate sanitation
How are fungal nail infections diagnosed?
Accurate diagnosis is crucial before starting treatment. Typically, a clinician will collect nail clippings or scrapings from the affected area and send them to a laboratory for analysis. Identifying the specific fungal species helps guide the optimal therapy.
Fungal nail infection treatment
Treating fungal nail infections can be challenging, often requiring over a year for the nail to look healthy again as the infected portion slowly grows out. Recurrences are possible even after effective therapy. Fingernails generally respond faster to treatment than toenails due to their quicker growth rate. Based on the infection’s severity and the organism involved, management options may include:
- Topical antifungal lacquers or creams
- Acidic topical agents
- Systemic (oral) antifungal medications
- Surgical or chemical nail removal to promote regrowth
In addition, maintain proper foot care during treatment: air out footwear often, sanitize shower floors, and keep surrounding surfaces tidy. Refrain from using nail polish, artificial nails, or other cosmetic products on the infected nails, and do not share footwear.
What are complications of a fungal nail infection?
If left unaddressed, onychomycosis can lead to inflammation, persistent discomfort, and a foul odor. Permanent nail deformity or spread of the infection beyond the nails is also possible. Individuals with poor circulation, such as those with diabetes, face a higher risk of serious complications.
When to see a doctor?
You should consult a healthcare professional if you suspect a fungal nail infection rather than self-treating. A precise diagnosis and targeted therapy improve clearance rates and reduce the chance of complications.
How to prevent fungal infections?
Preventing fungal nail infections largely depends on good foot and nail hygiene. You should:
- Wash your feet thoroughly and regularly
- Change damp or sweaty socks daily
- Avoid going barefoot in public showers, locker rooms, or pool areas
- Not share footwear with others
- Dry your feet completely after bathing or swimming
- Trim toenails straight across and smooth any rough edges
- Choose breathable or open-toe shoes
- Never share nail clippers or files
- Wear waterproof gloves when performing wet tasks like dishwashing or cleaning