Foot

ONYCHOMYCOSIS (fungal nail infections)

EPIDEMIOLOGY:
Onychomycosis occurs in 10% of the general population but is more common in older adults; the prevalence is 20% in those older than 60 years and 50% in those older than 70 years.The increased prevalence in older adults is related to peripheral vascular disease, immune disorders, and diabetes mellitus. The risk of onychomycosis is 1.9 to 2.8 times higher in people with diabetes compared with the general population. In patients with human immunodeficiency virus infection, the prevalence ranges from 15% to 40%

MECHANISM OF INJURY/CAUSES:
Fungal infections are opportunistic. This can mean that trauma to the nail or environmental factors allow the infection to penetrate the nail and thrive. The presence of tinea pedis (fungal skin infection) or other comorbidities can increase your risk of a fungal nail infection.

KEY ASSESSMENTS REQUIRED:

● Physical appearance/examination – the affected nail is typically discoloured, thickened and brittle. Change in nail shape may be present or in some cases the nail and nail bed can separate.
● Microscopic examination and culture – whilst a clipping of the affected nail can be sent to pathology there is the possibility of a false-negative result in approximately 5-15% of cases. This is likely because the area that was able to be clipped away did not contain the most number of active fungal cells.

EVIDENCE-BASED TREATMENT/MANAGEMENT REQUIRED:

EVIDENCE-BASED TREATMENT/MANAGEMENT REQUIRED:
Treatment is aimed at eradication of the causative organism and return of a normal appearance of the nail. A choice of the following is selected case by case:
● Systemic anti-fungals (oral medication) are the most effective treatment with a cure rate of 76% for terbinafine. It is noted however that oral medications can have more side effects risks and a consult with your general practitioner is essential to obtain a prescription.
● Topical therapy such as ciclopirox is less effective with a 40% success rate. Concomitant nail debridement further increases cure rate. Topical treatments are more accessible with fewer side effect risks and can be found in the pharmacy.

The selection of treatment is dependent on the individual and can be decided upon collaboratively with your Podiatrist and General Practitioner.

PROGNOSIS:

Treatment length depends on the treatment’s effectiveness and how long it takes for your toenail to grow out so no more infection is present. This can take up to 6-12 months. Despite treatment, the recurrence rate of onychomycosis is 10-50% as a result of re-infection or lack of complete elimination of fungal cells. Your podiatrist can recommend methods of preventing recurrence and treatment failure.