(Tinea Unguium; Fungal Nail Infection)
by Diane W. Shannon, MD, MPH
Onychomycosis is an infection of the nail. The infection occurs more often on toenails than fingernails.
The infection is caused by a fungus. The type that causes onychomycosis live in warm, moist environments. The fungus spreads to humans after direct contact.
Risk Factors TOP
Anyone can get fungal nail infections. Factors that increase your chances of onychomycosis include:
Onychomycosis can affect one or more nails. It is more common on toenails.
Onychomycosis may cause:
Your doctor will ask about your symptoms and past health. A physical exam will be done. The doctor may scrape or clip the nail. A sample will be sent for testing. Results make take several weeks.
Onychomycosis can be difficult to treat. It may return after treatment. Nails also grow slowly. It can take up to a year for treatment to completely clear the nail. Talk with your doctor about the best treatment plan for you. Treatment options include:
To help reduce your chances of onychomycosis:
American Academy of Dermatology
Foot Health Facts—American College of Foot and Ankle Surgeons
Canadian Podiatric Medical Association
The College of Family Physicians of Canada
Nandedkar-Thomas MA, Scher RK. An update on disorders of the nails. J Am Acad Dermatol. 2005;52(5):877-887.
Onychomycosis. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115521/Onychomycosis . Updated December 3, 2018. Accessed January 11, 2019.
Onychomycosis. Merck Profesional Manula. Available at: https://www.merckmanuals.com/professional/dermatologic-disorders/nail-disorders/onychomycosis. Updated November 2017. January 11, 2019.
Westerberg DP, Voyack MJ. Oonychomycosis: Current trends in diagnosis and treatment. Am Fam Physician. 2013;88(11):762-770.
Last reviewed January 2019 by EBSCO Medical Review Board Monica Zangwill, MD, MPH
Last Updated: 1/8/2019