Definition

Onychomycosis is an infection of the nail caused by a fungus. The infection occurs more often on toenails than fingernails.

Fungal Infection of the Toenails

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Causes

The fungi that cause onychomycosis thrive in warm, moist environments. Factors that may contribute to onychomycosis include:

• Injury to the nail
• Exposure to warm, moist environments, like locker rooms
• Damp socks
• Tight fitting shoes
• Poor nail care

Risk Factors

These risk factors increase your chance of developing onychomycosis. Tell your doctor if you have any of these risk factors:

• Age: 60 or older
• Smoking
• Type 1 or Type 2 diabetes
• Circulatory disorders, such as peripheral vascular disease
• Immune system disorders, such as HIV

Symptoms

Onychomycosis can affect one or more nails.

Symptoms include:

• Thickened nail that is difficult to cut
• Brittle or ragged nail
• Discolored or unsightly nail
• Pain in the nail when doing ordinary activities

Diagnosis

Your doctor will ask about your symptoms and medical history, and do a physical exam. You may need to be referred to a doctor who specializes in skin and nail disorders (a dermatologist). The doctor may scrape or clip the nail to send a sample for testing.

Tests on the nail sample may include:

• Culture
• Microscopic examination

Treatment

Since nails grow slowly, it can take up to a year to have a completely clear nail. Onychomycosis can be difficult to treat and may return after treatment. Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Prevention

To help reduce your chance of getting onychomycosis, take the following steps:

• Keep your feet clean. Dry them completely after washing.
• Keep your hands dry and wear rubber gloves when cleaning.
• Keep nails short and clean, trimming them straight across.
• Do not trim or pick at the skin near your nails.
• Take care to avoid injuring your toenails.
• Avoid shoes that are too tight.
• Wear absorbent cotton socks. Change them if they become damp.
• Avoid walking barefoot around swimming pools, locker rooms, and other public places.
• Choose a reputable salon for manicures and pedicures.
• Avoid artificial nails, which can trap moisture.
• If you smoke, quit.
• If you have diabetes, see your doctor about steps you can take to better control your blood sugar.