Fungal infection of the nails is called onychomycosis. It usually affects the toenails but sometimes the fingernails are also involved. It can originate from the same fungi that cause athlete’s foot, jock itch and ringworm, and causes about half of all nail abnormalities. Common sources of fungal infections include public swimming pools and gym locker rooms and showers.
Nail infections are more common in the elderly and are less common in children. Risk factors for onychomycosis are athlete’s foot, psoriasis, excessive sweating, trauma, old age, obesity, diabetes and individuals with lower immune systems. It is easily spread amongst family members.
You may be able to tell if you have a fungal infection just by examining your nails for changes in appearance. Examine your nails for signs, such as the following:
- Do nails look brittle?
- Has the nail shape changed?
- Are the nail edges crumbling?
- Is there debris trapped under the nail?
- Does nail seem to be loose or lifting?
- Is the nail thicker than before?
- Do you notice white or yellow streaks?
- Are nails dull and lacking shine?
Many different factors can lead to fungal infections:
- Using tools that have been used on other people
- Minor skin or nail injuries
- Nail deformities or disease
- Prolonged exposure to moist conditions
- Having diabetes, poor blood circulation, or a weakened immune system
- Wearing closed-in footwear, especially if made of material that does not breathe
You can help to keep fungal infections at bay by observing these practices:
- Keep skin clean and dry
- Do not share tools such as nail files
- Trim your nails straight across
- Use an antifungal spray or powder daily
- Give feet a break from shoes
- Do not go barefoot in locker rooms or public showers, and wear flip flops
- Examine toenails regularly
The only way to accurately tell whether you have a fungal infection is for your doctor to take a sample (by clipping or scraping under the nail) and send it to a lab, where it will be examined under a microscope and cultured (grown in a Petri dish).
Treating fungal infections generally requires prescription-strength topical and/or oral medication. Topical lacquers can require close to 1 year of treatment with a complete cure rate of up to 20%. Oral medications for toenail infections are pills taken daily for 3 months with a success rate of about 40% complete cure rate.
Even when a fungal infection does go away, there is a good chance, about 25%, that it will return.
Not all nail infections need to be treated. It is important to have a discussion with your doctor whether treatment is needed and whether a topical lacquer or an oral medication is the best treatment for you. There are far fewer side effects with topical medications than oral medications. Topical medications are often used when only a few nails are involved, and oral medications (pills) are used when many nails are involved.