Starts at the ends of the nails and raises the nail up: This is called "distal subungual onychomycosis." It is the most common type of fungal infection of the nails in both adults and children. It is more common in the toes than the fingers, and the great toe is usually the first one to be affected. Risk factors include older age, swimming, athlete's foot, psoriasis, diabetes, family members with the infection, or a suppressed immune system. It usually starts as a discolored area at a corner of the big toe and slowly spreads toward the cuticle. Eventually, the toenails will become thickened and flaky. Sometimes, you can also see signs of athlete's foot in between the toes or skin peeling on the sole of the foot. It is often accompanied by onycholysis. The most common cause is T. rubrum.
One way to contract athlete's foot is to get a fungal infection somewhere else on the body first. The fungi causing athlete's foot may spread from other areas of the body to the feet, usually by touching or scratching the affected area, thereby getting the fungus on the fingers, and then touching or scratching the feet. While the fungus remains the same, the name of the condition changes based on where on the body the infection is located. For example, the infection is known as tinea corporis ("ringworm") when the torso or limbs are affected or tinea cruris (jock itch or dhobi itch) when the groin is affected. Clothes (or shoes), body heat, and sweat can keep the skin warm and moist, just the environment the fungus needs to thrive.

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.


Nail infections occur more often in men than in women, and the infections are found in adults more often than in children. If you have family members who often get these types of fungal infections, you’re more likely to get them as well. Older adults are at the highest risk for getting fungal infections of the nails because they have poorer circulation and their nails grow more slowly and thicken as they age.
In normal, healthy people, fungal infections of the nails are most commonly caused by fungus that is caught from moist, wet areas. Communal showers, such as those at a gym or swimming pools, are common sources. Going to nail salons that use inadequate sanitization of instruments (such as clippers, filers, and foot tubs) in addition to living with family members who have fungal nails are also risk factors. Athletes have been proven to be more susceptible to nail fungus. This is presumed to be due to the wearing of tight-fitting, sweaty shoes associated with repetitive trauma to the toenails. Having athlete's foot makes it more likely that the fungus will infect your toenails. Repetitive trauma also weakens the nail, which makes the nail more susceptible to fungal infection.
Psoriasis is a long-term skin condition that may cause large plaques of red, raised skin, flakes of dry skin, and skin scales. There are several types of psoriasis, including psoriasis vulgaris, guttate psoriasis, inverse psoriasis, and pustular psoriasis. Symptoms vary depending on the type of psoriasis the patient has. Treatment of psoriasis may include creams, lotions, oral medications, injections and infusions of biologics, and light therapy. There is no cure for psoriasis.
Treatment: Nail fungus is a difficult condition to properly treat due to the average time before seeing results and the general lack of understanding regarding topical treatments. Fungus grows underneath the nail bed, making it extremely difficult to target. Certain nail fungus products, like topical ointments, contain nail penetrating ingredients that treat fungal nail infections underneath the nail bed where it grows.
Occlusive shoe materials, such as vinyl, which cause the feet to remain moist, provide an excellent area for the fungus to proliferate. Likewise, absorbent socks like cotton that wick water away from your feet may help. Some individuals who sweat excessively benefit from the application of antiperspirants like 20% aluminum chloride (Drysol). Powders can help keep your feet dry. Although counterintuitive, if your feet can be soaked in a solution of aluminum acetate (Burow's solution or Domeboro solution) and then air dried with a fan, this can be very helpful if performed three or four times within 30 minutes. A home remedy of dilute white vinegar soaks, using one part vinegar and roughly four parts water, once or twice a day (as 10-minute foot soaks) may aid in treatment followed by evaporation can be helpful.
Patience is key, as treatment duration varies from 2-3 months for oral treatments to up to 12 months for topical treatment. Because the nails take a long time to grow (6 months for fingernails and 12-18 months for toenails), it will take some time for the infection to resolve and the nail appearance to improve, regardless of the type of treatment used. Sometimes treatment may not be successful and your doctor may prescribe a different medication.
For more severe cases, oral antifungal medications might be required. These include fluconazole (an antifungal agent also commonly used to treat thrush), terbinafine (a broad-spectrum antifungal) and griseofulvin (usually used for skin infections). The latter is a very old drug and carries the risk of causing damage to the liver. Terbinafine is most effective and therefore is the preferred oral treatment. A 12-week course cures 70-80% of cases by causing the fungi’s cells to leak and die. It can, however, cause gastrointestinal side effects and depression.
Oils such as olive oil and sunflower oil contain ozone gas. A 2011 study published in the Brazilian Journal of Microbiology, showed that small doses of this kind of ozone, applied over a short period, can eliminate fungus. A different study, conducted at the National Center for Scientific Research, Cuba, found that sunflower oil was more effective than the prescription drug Xolegel (ketoconazole).
White superficial onychomycosis (WSO) is caused by fungal invasion of the superficial layers of the nail plate to form "white islands" on the plate. It accounts for around 10 percent of onychomycosis cases. In some cases, WSO is a misdiagnosis of "keratin granulations" which are not a fungus, but a reaction to nail polish that can cause the nails to have a chalky white appearance. A laboratory test should be performed to confirm.[15]

If you notice any redness, increased swelling, bleeding,or if your infection is not clearing up, see your health care professional. If a bacterial infection is also occurring, an antibiotic pill may be necessary. If you have fungal nail involvement, are diabetic, or have a compromised immune system, you should also see your physician for treatment.
The ease with which the fungus spreads to other areas of the body (on one's fingers) poses another complication. When the fungus is spread to other parts of the body, it can easily be spread back to the feet after the feet have been treated. And because the condition is called something else in each place it takes hold (e.g., tinea corporis (ringworm) or tinea cruris (jock itch), persons infected may not be aware it is the same disease.
The newer drugs are unlikely to cause any liver problems in patients without known liver disease. Blood tests are not needed for once-weekly treatment with fluconazole (Diflucan); however, people taking longer courses often have their liver function tested before starting the medicine and then retested during the course of treatment. It is important to notify the doctor of all side effects while on the medication. You should tell your doctor of all current medications to prevent potential serious drug interactions.
Toenail fungus, also called onychomycosis, is a common fungal infection of your toenail. The most noticeable symptom is a white, brown, or yellow discoloration of one or more of your toenails. It may spread and cause the nails to thicken or crack. Sandal season or not, toenail fungus typically isn’t what you want to see when you look at your feet. Luckily there are many treatments you can try.
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