Fungus among us - onychomycosis

By Dr. Tim Moser, Denver House Calls in Denver
Posted

Kristie was dreading warmer weather. Summer meant open toed shoes, and the thought of exposing her toenails to the public made her cringe inside. For the past several years, her nails had become thickened, yellow, and had lost their smooth outer surface. Worse yet, the condition had spread to her other toenails as well.

It all started after a heavy object fell on her foot, damaging her toenail. At first, there was bleeding under the nail, and it was very painful to walk. Within 2 weeks most of the pain was gone, but the new nail growing in did not look normal. Over time, the nail gradually looked worse and worse.

Out of desperation, Kristie made an appointment with her Family Medicine doctor. The doctor took a complete history, and suggested nail clippings be sent to a Pathologist to verify a fungal infection was present. When the doctor called Kristie about 1 week later, she confirmed the diagnosis of onychomycosis, otherwise known as tinea unguium.

Onychomycosis is a usually harmless infection of the nails, which usually affects the toes and sometimes the hands. It is caused by a type of fungus that is also responsible for athlete’s foot. Fungus thrives in warm, moist environments. Since most of us have sweaty feet, the toenails provide a perfect place for fungus to grow.

Oh, why does the fungus grow?

For those of you fluent in Latin, the name of the most common cause of fungus infections on the body is named Trichophyton rubrum. This little bugger is the cause of Athlete’s Foot (infection of the skin of the feet), as well as Jock itch (infection of the groin area, especially in men). Not an athlete? This opportunistic fungus can easily be picked up at the gym shower or public swimming pool, since anyone infected with the fungus can leave a nice trail on the ground as they walk.

Once your skin is infected, symptoms of Athlete’s Foot can develop. This is encouraged if you happen to wear shoes, and your feet sweat. The web spaces of the toes is the favorite locale for the fungus. Over time, it is only natural for the infection to migrate to the nail folds. Fungus is perfectly happy dining on the dead material that composes your toenails. Think of toenails in the same respect as your hair. Once it leaves the security of the nail fold, the nail material is completely dead. Lucky for us, the nails stick around to provide protection for the fingers and toes.

Thick as a brick

Fungus is an opportunistic infection that can take advantage of any type of trauma to the toenail. Many times the change in appearance of the toenail is attributed to the trauma itself. In reality, the thickened and brittle appearance is caused by the fungus. Over time, the toenails can take on bizarre and fantastic shapes, sometimes curling upwards into a spiral or back upon themselves in graceful loops. Pain often is an associated symptom during this stage, as the nails rub against the inside of your shoes. In this thickened state, the nails become difficult, if not impossible to trim with usual nail clippers found in your medicine cabinet. Podiatrist use nail clippers that resemble wire cutters. Wearing safety glasses are a good idea, since the pieces of cut nail have a tendency to fly away at great speed, and could cause eye damage.

Just make it go away!

Most patients find the appearance of an infected toenail unsightly. It is difficult to make an infected nail look normal, especially as the infection progresses. Nail polish goes only so far....

Since the fungus that causes onychomycosis grows slowly in an area of the body that has no blood supply, treatment can be challenging. Taking oral medication can lead to a cure in some cases, but the medication must be continued for months to be effective. Side effects of most of the oral medications can include liver damage, so routine blood tests are often used to keep an eye on things. If the liver is not happy, the medication is stopped.

Topical therapy, or applying medicine directly to the toenail, is an attractive alternative since there is little potential for liver problems. Unfortunately, since the medication has a difficult time penetrating the nail, this is the least effective treatment option.

The newest (and possibly most effective) method for treating onychomycosis is laser therapy. In essence, the fungus is killed directly by high intensity laser light. There is little potential for effects on other parts of the body, and the procedure is painless (except for the fungus)!. Since this is a relatively new way of treating onychomychosis, the procedure is a little expensive. Laser therapy is available in several locations in the Denver metro area.

Perhaps the most invasive way to treat a toenail infection is to remove the nail completely. This procedure may be performed under local anesthesia in a doctor’s office. Removing the nail does not guarantee the nail will not be infected again once it grows back, but it can provide months of relief.

Want more information about onychomycosis?

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002306/