A number of different types of fungus can cause onychomycosis including dermatophytes and Fusarium.[3] Risk factors include athlete's foot, other nail diseases, exposure to someone with the condition, peripheral vascular disease, and poor immune function.[3] The diagnosis is generally suspected based on the appearance and confirmed by laboratory testing.[2]
There are several preventive foot hygiene measures that can prevent athlete's foot and reduce recurrence. Some of these include keeping the feet dry, clipping toenails short; using a separate nail clipper for infected toenails; using socks made from well-ventilated cotton or synthetic moisture wicking materials (to soak moisture away from the skin to help keep it dry); avoiding tight-fitting footwear, changing socks frequently; and wearing sandals while walking through communal areas such as gym showers and locker rooms.[8][13][28]
You might cringe at the thought of having a fungal or yeast infection. The concept might feel icky. The reality, however, is that many types of fungi live on the skin all the time, even though you can't see them. Most of the time, these fungi don't cause any problems, but sometimes a fungus will change and cause an infection. These are some of the more common fungal and yeast infections that people experience.
Athlete's foot is a form of dermatophytosis (fungal infection of the skin), caused by dermatophytes, fungi (most of which are mold) which inhabit dead layers of skin and digests keratin.[2] Dermatophytes are anthropophilic, meaning these parasitic fungi prefer human hosts. Athlete's foot is most commonly caused by the molds known as Trichophyton rubrum and T. mentagrophytes,[21] but may also be caused by Epidermophyton floccosum.[22][23] Most cases of athlete's foot in the general population are caused by T. rubrum; however, the majority of athlete's foot cases in athletes are caused by T. mentagrophytes.[13]
Following effective treatment, recurrence is common (10–50%).[2] Nail fungus can be painful and cause permanent damage to nails. It may lead to other serious infections if the immune system is suppressed due to medication, diabetes or other conditions. The risk is most serious for people with diabetes and with immune systems weakened by leukemia or AIDS, or medication after organ transplant. Diabetics have vascular and nerve impairment, and are at risk of cellulitis, a potentially serious bacterial infection; any relatively minor injury to feet, including a nail fungal infection, can lead to more serious complications.[31] Infection of the bone is another rare complication.[6]
For some people, a fungal infection of the nails can be difficult to cure and the first round of medication might not work. The nail infection can’t be considered cured until a new nail that’s free from infection has grown in. Although this indicates that the nail is no longer infected, it’s possible for the fungal infection to return. In severe cases, there may be permanent damage to your nail, and it may have to be removed.

Onychomycosis does not necessarily require treatment.[3] The antifungal medication, terbinafine, taken by mouth appears to be the most effective but is associated with liver problems.[2][4] Trimming the affected nails when on treatment also appears useful.[2] There is a ciclopirox containing nail polish, but it does not work as well.[2] The condition returns in up to half of cases following treatment.[2] Not using old shoes after treatment may decrease the risk of recurrence.[3]
Cultured dairy or fermented foods (ideally organic and raw) — these are beneficial for replacing good bacteria in the gut since they provide probiotics. Probiotics help control yeast and also have numerous immune-enhancing effects. For other sources of probiotics, in addition to yogurt or kefir try cultured foods like kimchi, kombucha or sauerkraut.
Food intolerances — Some yeast infections are due to food allergies. Try to avoid foods that cause negative reactions of any kind and pay attention to symptoms you experience when eating things like dairy, eggs, certain nuts, wheat-containing foods and grains. If you think you have a food allergy or sensitivity, try an elimination diet to figure out what foods are causing intolerance and work on removing those foods.
When the skin is injured damaged, the natural protective skin barrier is broken. Bacteria and yeasts can then invade the broken skin. Bacteria can cause a bad smell. Bacterial infection of the skin and resulting inflammation is known as cellulitis. This is especially likely to occur in individuals with diabetes, chronic leg swelling, who have had veins removed (such as for heart bypass surgery), or in the elderly. Bacterial skin infections also occur more frequently in patients with impaired immune systems.
Athlete’s foot appears as a scaly red rash on the bottoms or sides of the feet often accompanied by itching, dry or cracked skin, stinging, and odor. You can also have moist, raw skin between your toes. Though athlete’s foot is fairly easy to treat with over-the-counter anti-fungal creams or sprays, this foot fungus is quite contagious and may easily spread to your toenails.
Nail fungus, or onychomycosis, is a common skin condition where a fungus infects a part of the nail including the bed, matrix, or plate.[1] Nail fungus can result in cosmetic concerns, pain, and discomfort as well as end up affecting your everyday activities. If it is a severe infection, it may cause permanent damage to your nails or may spread beyond your nails.[2] If you know you have toenail fungus, you can follow a few simple steps to get rid of it and return your toenail to its former health.
Topical agents such as amorolfine (Loceryl 5% nail lacquer; applied once or twice a week) and ciclopirox (Penlac 8% nail lacquer; applied daily) are usually prescribed for mild forms of the disease, but the treatment periods are long and their efficacy is somewhat limited due to poor nail plate penetration. These medications kill fungi by interfering with their cell membranes, which leads to their death.
Satchell, A. C., Saurajen, A., Bell, C., & Barnetson, R. StC. (2002, July 19). Treatment of interdigital tinea pedis with 25% and 50% tea tree oil solution: A randomized, placebo-controlled, blinded study [Abstract]. Australasian Journal of Dermatology, 43(3), 175–178. Retrieved from http://onlinelibrary.wiley.com/doi/10.1046/j.1440-0960.2002.00590.x/full
The medical name for fungal athlete's foot is tinea pedis. There are a variety of fungi that cause athlete's foot, and these can be contracted in many locations, including gyms, locker rooms, swimming pools, communal showers, nail salons, and from contaminated socks and clothing. The fungi can also be spread directly from person to person by contact. Most people acquire fungus on the feet from walking barefoot in areas where someone else with athlete's foot has recently walked. Some people are simply more prone to this condition while others seem relatively resistant to it. Another colorful name for this condition is "jungle rot," often used by members of the armed services serving in tropical climates.
Chronic nail trauma, such as repeatedly starting and stopping, kicking, and other athletic endeavors, can cause damage to the nails that can look a lot like fungal nails. This sort of repetitive trauma can also occur with certain types of employment or wearing tight-fitting shoes. Some traumas may cause permanent changes that may mimic the appearance of fungal nails.

Terbinafine can cause gastrointestinal (stomach and bowel) problems and a temporary loss of taste and smell. It can also interact with certain antidepressants and heart medications. Overall, terbinafine has far fewer drug-drug interactions than itraconazole. Nevertheless, it’s still important to tell your doctor if you are taking any other medication. As a precaution, this medication should not be taken during pregnancy or if you are breastfeeding.
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 final step to removing fungal and yeast infections is taking supplements, such as the probiotic supplement that I mentioned above. A quality probiotic supplement will help you get rid of the yeast and candida in your system that’s truly causing your toenail fungus. I personally recommend a probiotic supplement that has at the very least 10+ strains of probiotics with at least 15 billion CFUs.
Because you’re removing the majority of sugars and grains from your diet, in addition to fiber, I also recommend increasing the amount of protein-rich foods you’re eating. Make sure to buy grass-fed meat; organic, cage-free eggs or poultry; raw, unpasteurized dairy; and wild-caught fish — this is key for obtaining enough protein while also reducing toxins in your diet.
If the diagnosis is uncertain, direct microscopy of a potassium hydroxide preparation of a skin scraping (known as a KOH test) can confirm the diagnosis of athlete's foot and help rule out other possible causes, such as candidiasis, pitted keratolysis, erythrasma, contact dermatitis, eczema, or psoriasis.[13][23][27] Dermatophytes known to cause athlete's foot will demonstrate multiple septate branching hyphae on microscopy.[13]
Athlete's foot is a form of dermatophytosis (fungal infection of the skin), caused by dermatophytes, fungi (most of which are mold) which inhabit dead layers of skin and digests keratin.[2] Dermatophytes are anthropophilic, meaning these parasitic fungi prefer human hosts. Athlete's foot is most commonly caused by the molds known as Trichophyton rubrum and T. mentagrophytes,[21] but may also be caused by Epidermophyton floccosum.[22][23] Most cases of athlete's foot in the general population are caused by T. rubrum; however, the majority of athlete's foot cases in athletes are caused by T. mentagrophytes.[13]
​The American Orthopaedic Foot & Ankle Society (AOFAS) offers information on this site as an educational service. The content of FootCareMD, including text, images and graphics, is for informational purposes only. The content is not intended to substitute for professional medical advice, diagnoses or treatments. If you need medical advice, use the "Find an Orthopaedic Foot & Ankle Surgeon" tool at the top of this page or contact your primary doctor. 
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.
Swelling and redness of the skin around the nail is called paronychia. This is an infection of the skin at the bottom of the nail (cuticle). If the infection is acute (has a rapid onset), it is usually caused by bacteria. It may respond to warm soaks but will often need to be drained by a doctor. A chronic paronychia occurs when a cuticle becomes inflamed or irritated over time. Sometimes, yeast will take advantage of the damaged skin and infect the area as well. Therapy begins with keeping the skin dry and out of water. If the problem continues, a physician should be consulted. Antibiotics are not often used but may be necessary in severe infection.
Removal of the nail can reduce symptoms rapidly, but regrowth of the nail can take one year during which time local treatment for fungus can be used. Oral medications include terbinafine (Lamisil), itraconazole (Sporanox), and griseofulvin (Fulvicin). Treatment regimens vary and can last between six weeks and one year. Side effects of systemic treatment include gastrointestinal disorders, liver toxicity, skin rash and other hypersensitivities. These medications should not be taken during pregnancy or if there is a chance you will become pregnant because of effects on the fetus.
Oral medications include terbinafine (76% effective), itraconazole (60% effective) and fluconazole (48% effective).[2] They share characteristics that enhance their effectiveness: prompt penetration of the nail and nail bed,[23] and persistence in the nail for months after discontinuation of therapy.[24] Ketoconazole by mouth is not recommended due to side effects.[25] Oral terbinafine is better tolerated than itraconazole.[26] For superficial white onychomycosis, systemic rather than topical antifungal therapy is advised.[27]
Healing time depends on the type of treatment used. Prevention of a new infection is important. Orthopaedic foot and ankle specialists recommend good foot hygiene with frequent changing of stockings and rotating pairs of shoes to allow them to completely dry between uses. Also, avoid going barefoot in locker rooms and around swimming pools. If you have a pedicure, make sure the nail salon uses sterilized instruments.

If you observe any abnormal nail changes it is important to visit your doctor for prompt assessment. In addition to being cosmetically unappealing, OM can also lead to more serious complications, including the possible loss of your nail, bacterial infections, or cellulitis. Speak with your healthcare provider to determine what the best treatment plan is for you.


Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
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