Fungal nail

Created: 09.01.2025

Updated 09.01.2025

Approved by: Consultant Dermatologist, Dr James Denny

What is a fungal nail?

Nail fungus (also known as onychomycosis or tinea unguium) is a fungal infection that affects approximately 10% of the population, and it can occur on both fingers and toes. The fungus that attacks the nails feeds on keratin, which is the protein that forms the main component of the nails. In the event of a fungal infection, the nail will therefore break down more and more.

What are the symptoms?

Symptoms of nail fungus can vary somewhat, but it is common for the nail to take on a yellowish tinge, for it to become deformed and eventually for the nail to loosen completely. Nail fungus typically occurs in older people, in people with a weakened immune system and in people who, for various reasons, walk a lot in tight and damp footwear.

What are the treatments?

Although nail fungus is not dangerous for most people, for many it will be experienced as both unpleasant and embarrassing, and then it will be necessary to get treatment to get rid of the problem. Another good reason to get treatment, and ideally as soon as possible, is that a lack of treatment can cause the nail fungus to spread to several nails over time and/or cause an infection in the skin between the nails.

The most commonly used treatments against nail fungus are tablets or local treatments in the form of cream or nail polish. Medical nail polish will be most appropriate in cases where the nail fungus has had a limited spread, while tablets will be appropriate when larger parts of the nail have been infected. In both cases, the goal is for the drugs to kill the fungus so that the new nail that grows out can grow normally, but it is often very difficult to get the drugs to penetrate the nail.

What is the prognosis?

The prognosis of onychomycosis depends on factors such as the type of fungus, the severity and duration of the infection, the affected nails, and the patient’s overall health. With appropriate treatment, such as oral or topical antifungals, a complete cure is possible, although it may take 6–18 months for healthy nails to fully grow out.

Early, mild infections respond better to treatment, while severe cases with significant nail thickening or detachment are harder to manage and may require prolonged therapy. Conditions like diabetes, peripheral vascular disease, or immunosuppression can complicate treatment and increase the risk of recurrence, as can advanced age due to slower nail growth.

Consistent adherence to treatment is crucial for success, but onychomycosis has a high recurrence rate even after resolution. Without treatment, the infection typically persists and may worsen over time. Early diagnosis, addressing underlying health issues, and adopting preventive measures, such as good foot hygiene and avoiding communal showers, can improve outcomes and reduce the risk of reinfection.