Scratching infected areas may also spread the fungus to the fingers and under the fingernails. If not washed away soon enough, it can infect the fingers and fingernails, growing in the skin and in the nails (not just underneath). After scratching, it can be spread to wherever the person touches, including other parts of the body and to one's environment. Scratching also causes infected skin scales to fall off into one's environment, leading to further possible spread.
The Internet is filled with anecdotal information on how to cure toenail fungus using home remedies. Vinegar is a commonly recommended home remedy. Some people apply various oils such as tea tree oil, coconut oil, essential oils, and oil of cedar leaf (such as Vicks VapoRub) to their nails as well. The effectiveness of these home remedies is highly doubtful. Application of household bleach and hydrogen peroxide is also not recommended due to lack of evidence that these treatments work. These agents can also cause unwanted skin irritation. Thickened nails that have been affected by fungus can be difficult to trim. Using topical urea cream will soften the nail and make it easier to trim. These creams do not require a prescription.
Athlete's foot occurs most often between the toes (interdigital), with the space between the fourth and fifth digits most commonly afflicted. Cases of interdigital athlete's foot caused by Trichophyton rubrum may be symptomless, it may itch, or the skin between the toes may appear red or ulcerative (scaly, flaky, with soft and white if skin has been kept wet), with or without itching. An acute ulcerative variant of interdigital athlete's foot caused by T. mentagrophytes is characterized by pain, maceration of the skin, erosions and fissuring of the skin, crusting, and an odor due to secondary bacterial infection.
Keeping socks and shoes clean (using bleach in the wash) is one way to prevent fungi from taking hold and spreading. Avoiding the sharing of boots and shoes is another way to prevent transmission. Athlete's foot can be transmitted by sharing footwear with an infected person. Hand-me-downs and purchasing used shoes are other forms of shoe-sharing. Not sharing also applies to towels, because, though less common, fungi can be passed along on towels, especially damp ones.
If you have diabetes or a weakened immune system, treatment is especially important. After getting a fungal nail infection, people who have diabetes have an increased risk of developing sores that do not heal. Sores that do not heal can lead to a serious health problem. It’s important to see a dermatologist (or other doctor) at the first sign of a nail problem. A dermatologist can tell you whether you have a nail infection or something else.