Definition

Onychomycosis is an infection of the toenail or fingernails.

Fungal Infection of the Toenails Copyright © Nucleus Medical Media, Inc.

Causes

The infection is caused by a fungus. It can spread to humans from direct contact. This type of fungus lives in warm, moist places such as showers.

Risk Factors

Things that increase the risk of onychomycosis include:

• Shoes that trap in moisture and warmth such as workboots
• Fungal infection of the foot called athlete's foot
• Injury to the nail
• Type 1 or type 2 diabetes
• Problems with blood flow, such as peripheral artery disease (PAD)
• Issues with the immune system, such as HIV infection

Symptoms

Onychomycosis may cause:

• Thickened nail that is difficult to cut
• Brittle or ragged nail
• Discolored or unsightly nail
• Pain in the nail with normal use

It may happen in one or more of the nails.

Diagnosis

The doctor will ask about and past health. A physical exam will be done. A piece of the nail may be removed for testing. Results make take several weeks.

Treatment

Onychomycosis can be hard to treat. It may return after treatment. Treatment options include:

• Antifungal medicine—may be pills or creams and lotions applied to the area
• Surgery—nail may need to be removed for severe infections

Nails grow slowly. It can take up to a year to clear the nail.

Prevention

Steps that may lower the chance of onychomycosis:

• Keep feet clean. Dry them completely after washing.
• Keep hands dry. Wear rubber gloves when cleaning.
• Keep nails short and clean. Trim them straight across.
• Do not trim or pick at the skin near nails.
• Do not wear shoes that are too tight.
• Wear cotton socks that can pull moisture away from skin. Change socks if they are damp.
• Use footwear when walking around swimming pools, locker rooms, and other public places.
• Avoid artificial nails. They can trap moisture.