Definition
Fungal infection of the nail
Epidemiology
Toenail affected 4x more common than fingernail
Prevalence has increased x 4 in last 2 decades
Aetiology
Dermatophytes most common cause
99% T rubrum & T mentagrophytes
- destroy nail by chemical or enzymatic process
Pathogenesis
First
- keratin of hyponychium is infected by the dermatophyte
Second
- involves nail bed & nail plate
- initially invades ventral plate which arises from nail bed
- intermediate plate has soft keratin & can become involved
- dorsal nail plate rarely involved
Clinical
Usually cosmetic problem only
- may become painful
Diagnosis
Microscopy of nail scrapings & culture studies
-> hyphae
- can culture if necessary
Management
Non-operative
Debride & remove part or all of nail
Topical agents less effective than systemic because don't target matrix
Oral antifungals
- griseofulvin & ketoconazole (need up to 1 year of treatment)
- terbinafine (Lamasil) & itraconazole (Sporanox)
- more effective with shorter treatment (3-6m)
- remain in the nail for 6 months
Operative
Zadek's
Terminal Syme amputation