Onychomycosis
Basics
Description
- Fungal infection of fingernails/toenails
- Caused mostly by dermatophytes but also yeasts and nondermatophyte molds
- Toenails are more commonly affected than fingernails.
- Synonym: tinea unguium
Epidemiology
Prevalence
Etiology and Pathophysiology
- Dermatophytes: Trichophyton (Trichophyton rubrum most common), Epidermophyton, Microsporum
- Yeasts: Candida albicans (most common), Candida parapsilosis, Candida tropicalis, Candida krusei
- Molds: Scopulariopsis brevicaulis, Hendersonula toruloidea, Aspergillus sp., Alternaria tenuis, Cephalosporium, Scytalidium hyalinum
- Dermatophytes cause 90% of toenail and most of fingernail onychomycoses.
- Yeasts, especially Candida, may involve fingernails (not uncommonly) or toenails.
- Dermatophytes can invade normal keratin, whereas nondermatophyte molds invade altered keratin (dystrophic/injured nails).
Risk Factors
- Older age
- Tinea pedis
- Occlusive footwear
- Cancer/diabetes/psoriasis
- Peripheral vascular disease
- Cohabitation with others with onychomycosis
- Immunodeficiency
- Communal swimming pools
- Smoking
- Peripheral vascular disease
- History of nail trauma
- Autosomal dominant genetic predisposition
General Prevention
- Keeping feet cool and dry
- Avoiding occlusive footwear
- Using sandals in public locker rooms and swimming pools
- Discarding or treating of infected footwear and socks (2)
Commonly Associated Conditions
- Immunodeficiency/chronic metabolic disease (e.g., diabetes)
- Tinea pedis/manuum
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Citation
Domino, Frank J., et al., editors. "Onychomycosis." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688475/3.3/Onychomycosis.
Onychomycosis. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688475/3.3/Onychomycosis. Accessed November 30, 2023.
Onychomycosis. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688475/3.3/Onychomycosis
Onychomycosis [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 November 30]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688475/3.3/Onychomycosis.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Onychomycosis
ID - 1688475
ED - Domino,Frank J,
ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688475/3.3/Onychomycosis
PB - Wolters Kluwer
ET - 27
DB - Medicine Central
DP - Unbound Medicine
ER -