Onychomycosis, aka Tinea Unguium, is a chronic fungal nail infection caused by dermatophytes (including the genera Trichophyton, Epidermophyton and Microsporum), the most common pathogens of onychomycosis, with Trichophyton rubrum and Trichophyton mentagrophytes accounting for over 90% of onychomycoses. Many of the remaining cases are caused by nondermatophyte molds (e.g. Aspergillus, Scopulariopsis, Fusarium).
Toenail fungus is ugly, embarrassing, and easy to catch in nail salons, locker rooms, public showers and similar moist environments. The fungus often begins as an infection in the skin called tinea pedis (aka athlete’s foot).
Dermatophytes get under the nail fold at the end of the nail and grow underneath the nail. When they take hold, the nail may become thicker, yellowish-brown or darker in color, deformed and foul smelling. Debris may collect beneath the nail plate, white marks frequently appear on the nail plate, and the infection is capable of spreading to other toenails, the skin, or even the fingernails.
Nail bed injury like a hangnail or an ingrown toenail may make the nail more susceptible to all types of mycotic infection, including fungal infection.
Diagnosis is made by appearance, wet mount, culture, PCR, or a combination. If tests are performed, they may include:
- Skin culture (fungi from flecks of skin are able to grow in the lab)
- Skin lesion biopsy (examination may show fungus under the microscope)
- Skin lesion KOH exam (skin scrapings in KOH show fungus under the microscope)
Those who suffer chronic diseases, such as diabetes, psoriasis, tinea pedis, circulatory problems, or immune-deficiency conditions, are especially prone to fungal nails. Other contributory factors may be a history of Athlete’s foot, smoking and excessive perspiration.
- What other conditions can be mistaken for fungal nails?
- What do fungal nails look like?
- Where does fungus come from?
- Is nail fungus contagious?
- How is nail fungus treated?
- Are oral medications for nail fungus toxic?
- What is the cost of oral medications?
- Pictures of Foot Problems – Slideshow
Types of nail fungi (photo galleries)
- Distal Subungual Onychomycosis, and
- Proximal Subungual Onychomycosis can be a lifelong
infection and hard to treat; - White Superficial Onychomycosis is easier to treat.
Symptoms
The following nail changes may indicate that you have fungus:
- Nails become brittle
- The shape of the nail is changing
- Nails begin crumbling
- Debris gets trapped under the nail
- Nails begin to discolor, lose luster and shine
- Nails loosen and detach
- Nails grow thicker and deformed
- Foul smelling pus comes out
More pictures of fungal nails
Current treatment options for onychomycosis
If fungal nail infection is not treated, it won’t go away, and it will get worse and may seriously impair the quality of life. But fungal infections can be hard to treat. If you do treat it, you could spend a lot of money, and the treatment might not work.
Topical drugs
A general treatment plan, which is typically prescribed by a podiatrist, will include a topical preparation with undecenoic acid and chloroxylenol in oil based tincture as the first line treatment. Antifungal topical medicine (anti-fungal creams, lotions, gels, and lacquers) are applied to the infected nail and surrounding areas of the skin. The plethora of topical antifungal agents includes terbinafine (Lamisil), ciclopirox (Penlac), ketoconazole, oxiconazole nitrate, miconazole, butenafine, econazole, clotrimazole, naftifine, chloroxylenol + undecylenic acid, undecylenic acid, betamethasone + clotrimazole, sertaconazole, sulconazole, tolnaftate.
Topical medicines are unable to penetrate the nail plate. They may provide short term relief but recurrence is not unusual after discontinuing use. E.g. a prescription lacquer, painted on the toenails daily for 48 weeks, has a complete cure rate of less than 10 percent.
Over-the-counter creams and ointments may provide temporary and limited relief, but generally do not help treat the fungus. FDA conducted a research and published this report about the lack of efficacy of topical antifungal agents in 2004. No major advances have been made since then.
If topicals are unsuccessful, and depending on patients health, oral antifungal treatment may be attempted.
Oral antifungal agents
Antifungal pills are used for severe fungal nail infection. Modern systemic antifungal drugs, such as itraconazole, fluconazole, terbinafine, ketoconazole and griseofulvin, have a more favorable risk-benefit ratio than previously used medicine and are currently used in the treatment of fingernail and toenail fungal infections and dermatophyte infections of glabrous skin in adults following unsuccessful topical therapy. These drugs are expensive and may have serious side effects. Elderly and individuals with liver or heart problems should not take them.
The persisting issues with the onychomycosis medications remains high cost, the need for liver function tests, care to monitor drug reactions, battling with insurance carriers, etc. There are some new broad spectrum antifungal medications that are more affordable, but they are not readily available and are “off-label” indication by the FDA.
Oral antifungals are more effective but require patient compliance for long periods of time, have a significant risk of liver toxicity, prolonged loss of taste, and life threatening drug interactions. These medicines may also interfere with other medications. Fungal resistance can occur when the oral antifungal agents are used for a long time. Most doctors agree that the efficacy of drug therapy is in the range of 20-50%.
In cases of onychodystrophy, the toenails are very unlikely to get better and treatment with oral medications not only lowers effectiveness rate, but may be contraindicated.
Topical + Surgery
Removal of an infected nail is used for severe or recurring fungal nail infections. Topically applied anti-fungal drugs may work somewhat better after a surgical removal or chemical dissolution of the nail plate.
In nonsurgical nail removal, a urea ointment is put on the nail, softening and dissolving it for easy removal.
In surgical nail removal, the infected nail and tissue is fully removed (avulsion) or partially removed (debridement).
Some podiatrists prefer aggressive nail debridement plus application of topical preparation (e.g. Naftin) in a gel form. The patient is asked to rub the gel into not only the nail but the posterior nail fold. Some patients demonstrate clearing of the nail, that is, the new nail growth emanating from the matrix.
Surgery is often ineffective and the traumatic procedure leaves patients without a nail for months at risk for re-infection.
Combination treatment
Conventional therapy of onychomycosis is prolonged and often frustrating, which is why combination therapy involving topical, oral and surgical measures has been advocated as the treatment of choice. However, most recent studies demonstrate that surgical nail avulsion with topical antifungal agents is not a very encouraging modality for the treatment of onychomycosis. The fungus apparently survives the surgery and the application of topical drugs does not kill it. Mycological, clinical and complete cure is statistically insignificant.
To learn more about efficacy of different medications review the list of clinical studies conducted in the U.S. for the treatment of Onychomycosis.
Recurring infections and prevention
Even after successful treatment a fungal nail infection can return, either as a new infection or as regrowth of the original fungi. Severe toenail infections, particularly those involving a big toe, are difficult to treat and tend to recur.
Laser treatment
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