Onychomycosis is an infection of the nail. The infection occurs more often on toenails than fingernails.
Fungal Infection of the Toenails
Copyright © Nucleus Medical Media, Inc.
Onychomycosis is caused by a fungus. The fungi that cause onychomycosis survive in warm, moist environments. It is spread through direct contact with the fungus.
Anyone can get fungal nail infections. Factors that increase your chance of onychomycosis include: Wearing shoes that trap in moisture and warmth, such as workbootsIncreased ageHaving athlete's footHaving an injury to the nailType 1
Circulatory disorders, such as
peripheral vascular disease (PAD)
Immune system disorders, such as
Onychomycosis can affect one or more nails. It most commonly occurs on toenails.
Onychomycosis may cause: Thickened nail that is difficult to cutBrittle or ragged nailDiscolored or unsightly nailPain in the nail when doing ordinary activities
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: CultureExamination under a microscope
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:
Antifungal medications are used to treat onychomycosis. Medications may be oral or topical.
Surgery to remove the nail is sometimes done in severe cases. A new nail grows in its place unless the nail matrix that makes the nail is destroyed.
To help reduce your chance of onychomycosis:
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.
Garcia-Doval I, Cabo F, et al. Clinical diagnosis of toenail
onychomycosis is possible in some patients: cross-sectional diagnostic study and
development of a diagnostic rule.
Br J Dermatol. 2010;163(4):743-751.
Nandedkar-Thomas MA, Scher RK. An update on disorders of the nails.
J Am Acad Dermatol. 2005;52:877-887.
Onychomycosis. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated July 27, 2012. Accessed December 3, 2012.
Rodgers P, Bassler M. Treating onychomycosis.
Am Fam Physician. 2001;63:663-672,677-678.
Thomas J, Jacobson GA, et al. Review
article. Toenail onychomycosis: an important global disease burden.
J Clin Pharm
Last reviewed October 2014 by David L Horn, MD, FACP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.