Sunday September 17, 2006
Fungal nail infections
MEDICINE CABINET
By DIONG SWEE HOON
FUNGI are microscopic organisms that do not require sunlight to survive. Some fungi have beneficial uses, while others cause illness and infection.
Fungal nail infections are typically caused by a fungus that belongs to a group of fungi called dermatophytes. But yeasts and moulds can also be responsible for nail fungal infections. All of these microscopic organisms live in warm, moist environments, including swimming pools and showers.
Onychomycosis (fungal nail infection) usually begins as a white or yellow spot under the tip of your fingernail or toenail. As the nail fungus spreads deeper into your nail, it may cause your nail to discolour, thicken and develop crumbling edges – an unsightly and potentially painful problem.
Fungal nail infections are most often seen in adults. They often follow fungal infections of the feet. Fungal nail infections may be difficult to treat and may recur often. Toenails are affected more often than fingernails.
How do you get a fungal nail infection?
Fingernail infection may occur after a toenail infection has become established. The fungus may spread to a finger if you scratch your itchy toes and toenail. It is also more likely to occur if you wash your hands frequently, or have them in water a lot. Constant washing may damage the protective skin at the base of the nail. This may allow fungi to enter.
A nail that has recently been damaged is also more likely to become infected. You have an increased risk of developing a fungal nail infection if you have various other conditions, for example, diabetes, psoriasis, poor circulation, a poor immune system (for example, if you have AIDS or are on chemotherapy), or if you have general poor state of health.
Nail infections are more common in people who live in hot or humid climates. Wearing socks and shoes that hinder ventilation and do not absorb perspiration may also be part of the cause.
Another possible way of contracting this infection is by walking barefoot in damp public places, such as swimming pools, gyms and shower rooms.
Smoking also increases the risk of developing a nail infection. In some cases, there is no apparent reason. Fungus germs (fungi) are common and an infection can occur “out of the blue”.
What are the symptoms?
You may have a fungal nail infection if one or more of your nails are:
Infected nails may also separate from the nail bed, a condition called onycholysis. You may even feel pain in your toes or fingertips and detect a slightly foul odour.
What is the treatment?
Topical medication
Severe nail-bed involvement is extremely unlikely to respond to topical treatment. Cure rates for toenail infections are poor. The BNF (British National Formulary) suggests that tioconazole and amorolfine be used for early fungal nail infection. Treatment needs to be continued for at least six months for fingernails and 12 months or longer for toenails.
Oral medication
Oral medications such as itraconazole or terbinafine may be taken for several months. The medication will also clear any associated fungal skin infection such as athlete’s foot.
While these medicines may clear the fungus in about half of all patients, they can cause numerous side-effects. Many people are not able to take these medications because of other medications that they are taking, or other medical problems.
Griseofulvin is no longer a first-line treatment for fungal nail infections (in the UK), except in children.
Nails grow slowly, so even if treatment is successful, a new, clearer nail may take up to a year to replace the old nail. One reason for treatment failure is some people stop their medication too early.
Antifungal nail paint
This is an alternative, but tends not to work as well as medication taken by mouth. It may be useful if the infection is just towards the end of the nail. This treatment does not tend to work so well if the infection is near the skin, or involves the skin around the nail. The nail paint has to be put on exactly as prescribed for the best chance of success. You may need six months of nail paint treatment for fingernails, and up to a year for toenails.
Nail removal
If other treatments have failed, an option is to have the nail removed by a small operation done under local anaesthetic. This is combined with treatment with antifungal medication.
How to prevent fungal nail infections?
Before sleep, thoroughly wash and dry your feet, and apply a topical antifungal directly to your skin or nail. Use the topical medication for a year.
Keep your feet dry. Dry feet are less likely to become infected. Apply powder to your dry feet after you take a shower or bath.
Wear dry cotton socks and change more than once a day if necessary.
Wear dry shoes that allow air to circulate around your feet. Avoid tight, enclosed shoes. Injury to the tips of the toes because of tight shoes may be the biggest single factor that leads to a fungal nail infection recurring.
Wear shower sandals or shower shoes when using a public pool or shower; allow them to dry between uses.
Don’t share shoes, socks, nail clippers, or nail files with others.
Avoid injuring your nail. Cutting nails too short is a common cause of nail injury.
References:
1. Bell-Syer S, Porthouse J, Bigby M: Oral treatments for toenail onychomycosis. The Cochrane Database of Systematic Reviews 2004, Issue 2.
2. Mayo Clinic, USA – Nail Fungal Infections
RSS
