Onychomycosis refers to a fungal infection of the toe or
finger nail. Onycho refers to the nail and mycosis refers to a fungal
condition. Onychomycosis is very common in the toe nail and seen to a much
lesser degree in the finger nail. It is estimated that 25 million
Americans suffer from onychomycosis. The organisms that cause
onychomycosis are usually fungus (90% of cases) or yeast (7% of
cases).
Onychomycosis has nothing to do with hygiene. Many
people feel that they have in some way contributed to a fungal nail
infection. There is only one way we do contribute to
this condition and that is in that we create an environment that is wonderfully
conducive to the growth of fungus. We jump out of the shower in the
morning, put on our socks and shoes for 18 hours and create a greenhouse that
promotes fungal growth.
It is safe to say that 50% of folks over the age of 50 have a
fungal toe nail infection to some degree. But this doesn't necessarily
mean that onychomycosis is due to 'old age'. We can imply that over the
course of our lifetimes we would have more opportunities to acquire a fungal
infection of the nail. Trauma makes the nail much more susceptible to
fungal infections. It's also reasonable to assume that folks in
professions that abuse their feet would tend to have a higher rate of
onychomycosis. An injury to the nail is a common precursor to a fungal
nail infection. Trauma may be something abrupt such as a can of beans
hitting the nail from the top shelf or something as benign as a pair of
ill-fitting shoes constantly rubbing on the nail. As an example, a
machinist or mechanic would tend to show earlier signs of onychomycosis than a
housewife.
The appearance of onychomycosis can vary but most cases begin
at the distal tip of the nail and slowly progress into the nail over a period of
months to years. The nail will thicken as the fungus continues to
grow. The filaments of fungus take up space in the nail causing it to
swell. The nail can be yellow, white or even green to black. The
nail also begins to be chalky and flakey.
Treatment of toe nail fungus and onychomycosis
Prevention of injuries to the nail is very important.
Once the nail is injured, the door of susceptibility swings open, allowing entry
of the fungus. There are some very simple preventative measures that can
be taken on a regular basis. Keep the feet dry. Keeping the feet dry
will inhibit the ability of the fungus to thrive. You can do this in
several ways. Frequent changes of socks, the use of powder, such as baby
powder and rotating shoes so that they are worn only every other day, can help
tremendously.
Medications for onychomycosis fall into two categories;
topical and oral. There are any number of effective topical medications
available over the counter. Topical medications are most helpful in
treating early, small infections and for maintaining clear nails. Topical
medications do have a limited ability to penetrate the nail to reach all of the
fungal elements. Topical medication inhibit the growth of the fungus
allowing for faster growth of the nail. Remember,
the fungus doesn't take a day off. Compliance is a big issue when using
topical antifungals.
The FDA approved a new prescription strength topical
medication for treating onychomycosis in 1999 called Penlac. (Dermik
Laboratories, Collegeville, PA). Penlac is manufactured in Frankfurt,
Germany by Aventis Pharma Deutschland GmbH. Penlac doesn't carry the side
effects of the oral medications but the jury is still out on the efficacy of
this medication.
The older generations of oral antifungal medications, such as
Fulvicin or Griseofulvin, have been used successfully for years and are making a
comeback due to their economic value. The newer generation of oral
antifungals, including Sporanox and Lamisil have been received very well by the
medical community. Care should be taken when using Sporanox due to its'
potential liver toxicity. Both Sporanox and Lamisil are expensive
medications costing several hundred dollars for the recommended three month
course of treatment.
When all else fails, the fungal toe nail can be permanently
removed. This procedure is not difficult to perform and most patients
return to their normal shoes in just a Band-Aid in 24hrs. The removal of
the nail is permanent.
Which choice is right for you? Consider the following
two examples;
Case 1. Sandy is a 24 year old hairdresser who has intimate
hands on contact with her clients on a daily basis. She has developed a
fungal infection in several of her finger nails. She is concerned that the
fungal infection will have a direct impact on her livelihood and does not want
to spread the infection to others.
Case 2. Joe is a 62 year old farmer and has a long history of
injuries to his hands and feet. His last visit to the doctor showed signs
of an increase in his liver enzyme studies indicating an overall decrease in his
liver function. Joe has developed onychomycosis in most of his toe nails.
I think the choices for Joe and Sandy are clear but in most
cases the criteria to make recommendations for treatment of onychomycosis are
not as obvious. In those cases, patients should consult their physician to
discuss the pros and cons of oral antifungal treatment.
