Fungal Infections of the Nail (Onychomycosis)

Fungal Infections of the Nail (Onychomycosis)

Prepared by Richard C. Honour, PhD

Onychomycosis: Common fungal infections of the toenail (Onychomycosis) are generally poorly recognized, underreported and inadequately treated infectious diseases of the foot that may have serious complications. Nail fungal infections are treatable, although they can persist for years without causing pain.

Onychomycosis is a fungal infection that causes fingernails or toenails to thicken, discolor, disfigure and split. Without treatment, the nails can become thickened, causing irritation and pain. Onychomycosis has been estimated to be responsible for up to 50% of all nail diseases, and the incidence of onychomycosis is increasing. Recent large scale studies indicate that the prevalence of onychomycosis is nearly 14% in North America.

Disease Biology: Onychomycosis is an infection of the bed and plate underlying the surface of the nail. It is caused by various kinds of fungi, all of which are widespread in the environment. The primary fungi that cause onychomycosis are Trichophyton rubrum, Trichophyton mentagrophytes and other Trichophyton spp., although several other important fungi may be involved. These infections are normally confined to the nails, but may spread to the surrounding skin, and to other people.

Nail fungal infections represent a reservoir of fungi that can be transmitted through shoes and by direct contact. Consequently, infection can spread from the feet to other areas of the body within an individual. Also, infection can be transmitted between susceptible individuals. People with certain conditions are more susceptible to fungal nail infections and, therefore, may have a higher prevalence of the disease than the general population. Predisposing characteristics to onychomycosis include:
Increasing ager
Male genderr
Genetic susceptibilityr
Poor peripheral circulationr
Diabetes mellitusr
Immunosuppressionr
Nail trauma.

Disease Control: Onychomycosis should be considered a controllable disease, rather than a permanently curable disease. Individuals with nail infections should be encouraged to:
Discard old footwearr
Purchase multiple pairs of new shoesr
Replace insoles of shoesr
Alternate among different pairs of shoesr
Disinfect footwearr
Keep feet clean and dryr
Wear shower shoes in shared showers such as athletic facilitiesr
Regular manicures and pedicures under sterilized conditions is very importantr
Contact a physician at the first sign of recurrence

Treatment Strategies: Onychomycosis can be difficult to treat, and the available antifungal agents can produce side effects. There are topical and oral antifungal agents available to treat these infections, but the medicines work slowly, often requiring several months to eliminate an infection. Drugs with few adverse effects are preferred, such as topical antifungal agents, since the medication may need to be taken indefinitely. Treatment approaches can be categorized as:
Mechanical debridementr
Removal of the affected nailr
Oral antifungal therapyr
Topical antifungal therapy

Recurrence is likely with any single approach to treatment. Therefore, combining two or more approaches has the potential to maximize therapeutic efficacy and reduce recurrence. Treatment periods may vary from 3 months for oral products up to 12 months for topical products, and the effect of treatment may not be visible for several weeks or months into therapy.

Topical antifungal therapy can be effective for the treatment of onychomycosis. This involves the application of an antifungal product directly to the infected nail so that the product can diffuse through the nail plate to reach the site of infection. The use of botanical essential oils having known antifungal activity, such as the Eulara product Fungi, can be useful for the long-term management of nail infections because of the rapid penetration of the active essential oil ingredients through the nail surface to the site of the infection. The Eulara product, Fungi, may be reviewed at www.eulara.com.

The combined effects of the penetration of a topical antifungal product through the nail plate from the surface of the nail, plus diffusion of a systemic antifungal drug through the nail bed, may increase the total amount of antifungal activity at the site of infection. Using a combination of topical and oral antifungal strategies in this manner may potentially reduce the duration of therapy and allow a reduction in the dose of the oral agent.

Once the fungal nail infection has been successfully treated, continuous treatment with a topical antifungal product may reduce the frequency and severity of recurrence.

Adapted in part from the article, Progression and Recurrence of Onychomycosis, by Richard K. Scher, MD, FACP; Warren Joseph, DPM; Jeffrey Robbins, DPM (2003).

Note: This report and all of the information provided herein are offered to readers for their information only. Most of the data, information and materials presented in this report have been adapted from other sources, and none of the information represents original research by the Author or by Eulara. None of the information provided herein is intended as medical advice or treatment information of any kind. Anyone having or suspecting that they may have any infection or infectious disease should seek the advice of a medical professional immediately.

Updated February 2012