Onychomycosis – Fungal Infections of Fingernails or Toenails

INTRODUCTION
Onychomycosis is the medical term for a nail infection caused by a fungus. There are many different species of fungus that can cause onychomycosis. Once an infection develops, it can be difficult to eliminate. Yeast is the most common cause of fingernail onychomycosis. The majority of toenail onychomycosis is due to dermatophytes. The incidence of fungal infections increases with age. Risk factors include: nail trauma, occlusive footwear, incomplete drying of feet after showering, swimming, tinea pedis, psoriasis, diabetes mellitus, immunodeficiency and living with people who have onychomycosis. Fortunately, for most patients, fungal nail infections are primarily a cosmetic concern. However, they can cause discomfort or pain in more severe cases. Patients with diabetes mellitus, have an increased risk of bacterial infections.

SKIN FINDINGS
There are four patterns of nail infections. More than one pattern may occur simultaneously.

1. Distal subungual onychomycosis is the most commonly seen pattern. The distal (free edge at the top of the nail) gets infected with fungi and as a result, turns white to yellow in color. This discoloration eventually spreads to the entire nail. The infection also causes the nail to separate from the nailbed.
2. Proximal subungal onychomycosis is the most commonly seen pattern in immunocompromised patients. The fungi invade the proximal-cuticle area and infect the nail from below. The surface of the nail remains intact. However, the infection causes the nail to separate from the nailbed.
3. White superficial onychomycosis is caused by surface infection of the nail plate. This often starts as dull, white spots on the nail surface and eventually, the entire nail becomes soft, dry and powdery. However, the nail plate does not separate from the nailbed.
4. Candidal onychomycosis is a nail-plate infection. It is seen primarily in patients with the rare disease; chronic mucocutaneous candidiasis. The nail plate turns yellowish-brown in color and thickens. This condition usually involves all the fingernails.

TREATMENT OPTIONS

Topical Medications
Traditional topical antifungal creams/lotions are generally ineffective in the treatment of onychomycosis and are not recommended.

One topical prescription medication has been approved for the treatment of fungal nail infections. The medication is Penlac Nail Lacquer (ciclopirox topical 8% solution). Overall, Penlac has a low rate of effectiveness. However, it can be a treatment option in patients who are at high risk for complications with the use of oral medication therapy.

Oral Medications
Oral medication therapy has the highest rate of effectiveness, ranging from 50% to over 80%. However, treatment failure and reoccurrences are not uncommon. Oral medication tends to have the highest success rate in the treatment of fingernails and with younger patients. Lamisil (terbinafine) is generally considered first line treatment when using an oral medication. It has a higher rate of efficacy when compared to other oral medications and few serious side effects as well as fewer medication interactions. Patient with infected fingernails take 250 mg daily for six weeks and those with infected toenails take 250 mg daily for twelve weeks. There are other oral medications approved for the treatment of onychomycosis. These include Sporanox (itraconazole) and Diflucan (Fluconazole). Routine blood tests are recommended for patients being treated with any of these oral medications, as they can cause liver problems. Also, these medications can be quite expensive and are not a covered medication at McKinley Health Center.

Surgery Surgical removal of the nail plate is an option. However, recurrence rates are high.

GENERAL FOOT HYGIENE

• Wash your feet every day. Use warm (not hot) water.
• Dry feet and in between toes well.
• Wear clean socks and change them daily.
• Wear properly fitted shoes.
• You may use a moisturizer, but do not put it between your toes.

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