ONYCHOMYCOSIS

BACKGROUND

Fungal infection of the toenails or fingernails is caused by a fungal microbe that invades the nail bed. Fungal nail infection is also termed onychomycosis and tinea unguium.

At first, onychomycosis appears to be only a cosmetic concern. Without treatment, however, the toenails can become so thick that they press against the inside of the shoes, causing pressure, irritation, and pain. Fingernail infection may cause psychological, social, or employment-related problems.

DISEASE OCCURRENCE IN POPULATION:

Onychomycosis is a common problem and affects approximately 5% of the population worldwide and represents up to 50% of all nail diseases.

In Southeast Asia the prevalence of onychomycosis is relatively low than western population. This was partially confirmed by a large scale-survey in Asia in the late 1990s in which the prevalence of onychomycosis was lower in tropical countries (3.8%) than in subtropical countries and the countries in the temperate zone (18%).

One study conducted in Lahore, Pakistan found that onychomycosis is more common in women of 20 – 40 years of age.

RISK FACTORS:

Factors that can increase your risk of developing onychomycosis include:

• Being older, owing to reduced blood flow, more years of exposure to fungi and slower growing nails
• Perspiring heavily
• Being male, especially if you have a family history of nail fungal infections
• Working in a humid or moist environment or in a job where your hands are often wet, such as bartending or housekeeping
• Wearing socks and shoes that hinder ventilation and don't absorb perspiration
• Living with someone who has nail fungus
• Walking barefoot in damp communal areas, such as swimming pools, gyms and shower rooms
• Having athlete's foot
• Having a minor skin or nail injury or a skin condition, such as psoriasis
• immunosuppression (can occur fromHIV or certain drugs)
• Having diabetes, circulation problems, a weakened immune system or, in children, Down syndrome

SIGN AND SYMPTOMS:

Following symptoms may occur as the disease progresses:

• A fungal infection can cause a nail to:
• Turn white, yellow, or brown
• Get thick, change shape, or lift up
• Break off easily
• Hurt
• As the nail thickens, infection may interfere with standing, walking, and exercising.
• Paresthesia (a sensation of pricking, tingling, or creeping on the skin caused by pressure on or damage to nerves.)
• Pain,
• Discomfort, and
• Loss of agility (dexterity)
• Loss of self-esteem, embarrassment, and social problems can also develop.

Fungal nail infections don't usually lead to serious long-term problems. But in some people they can. In people who have diabetes or whose bodies have trouble fighting infections, the nail infection can make them more likely to get other infections.

DIAGNOSTIC TESTS:

A diagnosis of onychomycosis may be strongly suspected based upon physical findings. However, laboratory evidence to support a clinical diagnosis of onychomycosis is preferred because other nail disorders can resemble onychomycosis.

Usually, your doctor or nurse can tell if you have a fungal nail infection by talking with you and doing an exam. But to make sure, he or she might take a small sample of the nail and look at it under a microscope. Your doctor might also send the sample to a lab where another doctor can see which germs are causing the infection.

Tests may include potassium hydroxide (KOH) preparation, fungal culture or periodic-acid-Schiff (PAS) staining of nail plate clippings and fungal culture and / or Polymerase chain reaction (PCR).

TREATMENT OPTIONS:

If self-care strategies and over-the-counter (nonprescription) products haven't helped, your doctor may suggest a combination of prescription drugs and other approaches. But even if you find relief from your signs and symptoms, repeat infections are common.

MEDICATIONS:

ORAL ANTIFUNGAL DRUGS: Your doctor may prescribe an oral antifungal drug. Studies show the most effective treatments are terbinafine and itraconazole. These drugs help a new nail grow free of infection, slowly replacing the infected part.

You typically take this type of drug for six to 12 weeks. But you won't see the end result of treatment until the nail grows back completely. It may take four months or longer to eliminate an infection.

Treatment success rates with these drugs appear to be lower in adults over age. And treatment success seems to improve when you combine oral and topical antifungal therapies.

MEDICATED NAIL CREAM: Your doctor may prescribe an antifungal cream, which you rub into your infected nails after soaking. These creams may work better if you first thin the nails. This helps the medication get through the hard nail surface to the underlying fungus.

To thin nails, you apply an over-the-counter (nonprescription) lotion containing urea. Or your doctor may thin the surface of the nail (debride) with a file or other tool.

SURGICAL OR OTHER PROCEDURES:

NAIL REMOVAL: If your nail infection is severe or extremely painful, your doctor may suggest removing your nail. A new nail will usually grow in its place. But it will come in slowly and may take as long as a year to grow back completely. Sometimes surgery is used in combination with ciclopirox to treat the nail bed.

LASER AND LIGHT-BASED THERAPIES: More study is needed, but these methods — alone or with medications — may help your nails improve. One study tested the effectiveness of carbon-dioxide laser therapy combined with antifungal nail cream. Most of the 24 people in the study benefited from the treatment.

Laser and light-based therapies are not available everywhere, are expensive, and often are not covered by insurance.

PRECAUTIONS:

To reduce chance of getting infection you can do the following:

• Wash your hands and feet regularly and keep your nails short and dry: Wash your hands and feet with soap and water, rinse, and dry thoroughly, including between the toes. Trim nails straight across and file down thickened areas.
• Wear socks that absorb sweat: Fabrics effective at wicking away moisture include wool, nylon and polypropylene. Change your socks often, especially if you have sweaty feet.
• Choose shoes that reduce humidity: It also helps to occasionally take off your shoes or wear open-toe footwear.
• Discard old shoes: If possible, avoid wearing old shoes, which can harbor fungi and cause a reinfection. Or treat them with disinfectants or antifungal powders.
• Use an antifungal spray or powder: Spray or sprinkle your feet and the insides of your shoes.
• Wear rubber gloves: This protects your hands from overexposure to water. Between uses, turn the gloves inside out to dry.
• Don't trim or pick at the skin around your nails: This may give germs access to your skin and nails.
• Don't go barefoot in public places: Wear sandals or shoes around pools, showers, and locker rooms.
• Choose a reputable nail salon: Make sure the place you go for a manicure or pedicure sterilizes its instruments. Better yet, bring your own and disinfect them after use.
• Give up nail polish and artificial nails: Although it may be tempting to hide nail fungal infections under a coat of pretty pink polish, this can trap unwanted moisture and worsen the infection.
• Wash your hands after touching an infected nail: Nail fungus can spread from nail to nail.
• Avoid sharing nail tools, such as clippers and scissors.

REFERENCES:

• Microsporum spp. onychomycosis: disease presentation, risk factors and treatment responses in an urban population Erick Martínez,Mahreen Ameen,Diana Tejada,Roberto Arenas The Brazilian Journal of Infectious Diseases. 2013
• Bokhari MA, Hussain I, Jahangir M, Haroon TS, Aman S, Khurshid K., Onychomycosis in Lahore, Pakistan, Int J Dermatol. 1999 Aug;38(8):591-5.
• http://www.mayoclinic.org
• Eyerich K, Foerster S, Rombold S, et al. Patients with chronic mucocutaneous candidiasis exhibit reduced production of Th17-associated cytokines IL-17 and IL-22. J Invest Dermatol 2008; 128:2640.