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

Onychomycosis is caused by a fungus that infects the nail. The fungi that cause onychomycosis survive in warm, moist environments. It is spread through direct contact with the fungus.

Risk Factors

Anyone can get fungal nail infections. Risk factors that increase your chances of developing onychomycosis include:

• Wearing shoes that trap in moisture and warmth, such as workboots
• Increased age
• Having athlete's foot
• Having an injury to the nail
• 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. It most commonly occurs on toenails.

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. A physical exam will be done. 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. Results make take several weeks.

Tests on the nail sample may include:

• Culture
• Examination under a microscope

Treatment

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. Trim them straight across.
• Do not trim or pick at the skin near your nails.
• 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.
• Avoid artificial nails. They can trap moisture.
• If you have diabetes, see your doctor about steps you can take to control your blood sugar.