Nail fungus is most commonly seen in toenails but can also occur in fingernails. Often, there is a combination of fungal infection in both the skin and nails. Nail fungus is primarily a cosmetic concern, but it can occasionally cause mild pain and tenderness in and around the nail. Suspicion of nail fungus is based on the appearance of the nail.
The nail plate often becomes brittle and crumbles, especially at the outer edge. In some cases, the nail may completely break apart. However, the clinical diagnosis can be challenging, as these nail changes can also be seen in underlying skin conditions such as psoriasis. Only half of toenail abnormalities are actually caused by fungus. Therefore, it is recommended to submit a nail sample for laboratory testing to confirm the diagnosis (before considering long-term treatment). Fungal elements can also be directly detected under a microscope. Taking a sample prevents unnecessary treatment over several months if the fungus is not the cause of the nail changes.
Nail fungus is caused by various fungal species (dermatophytes). These fungi establish themselves in the upper layer of the skin and/or nails. They thrive in moist and warm environments and typically occur with increased foot sweating and tight footwear (e.g., synthetic socks and boots). Often, the fungal infection has been present in the skin for an extended period before spreading to nearby nails.
Nail fungus is a harmless condition and rarely spreads to other nails. Without treatment, the condition can persist indefinitely. However, treatment can be pursued to alleviate embarrassment, tenderness, and other symptoms.
If only the outer third of the nail is affected, initial treatment attempts can involve topical therapy (antifungal naillacquer). This treatment is carried out over several months, and recurrence is unfortunately common. Therefore, a long-term course of oral antifungal medication is often necessary, especially if multiple nails are affected. For most people, an oral antifungal course will be sufficient, but there are no guarantees.
Repeated laser treatments of the nail are also an alternative, but this method is not effective for everyone. Nail fungus is, therefore, a challenging condition to cure. Additionally, after successful treatment, it can take up to one and a half years for the nail to appear normal again, as a healthy nail needs to grow out.
As part of treatment and prevention, it is important to reduce the fungus's growth in the skin and nails by:
