From the Guidelines
Your thick, white toenail is likely due to a fungal infection called onychomycosis, and treatment with oral antifungal medication such as terbinafine 250mg daily for 12 weeks is recommended. This condition is characterized by a fungal invasion of the nail, causing it to thicken and discolor, and can lead to complications such as cellulitis, especially in elderly or diabetic patients 1. The infection is often caused by dermatophytes, with T. rubrum being the most common causative agent 1.
Causes and Risk Factors
- Fungal infections occur when fungi invade the nail through small cracks or separations between the nail and nail bed, thriving in warm, moist environments.
- Older adults, people with diabetes, or those with weakened immune systems are more susceptible to these infections.
- Diabetics are almost three times more likely to develop onychomycosis than nondiabetics, and may have increased difficulty in doing regular foot check-ups due to obesity or complications of diabetes 1.
Treatment Options
- Topical treatment is inferior to systemic therapy in all but a small number of cases of very distal infection or in SWO 1.
- Oral antifungal medication such as terbinafine 250mg daily for 12 weeks or itraconazole 200mg twice daily for one week per month, for two to three months, may be prescribed by a doctor for more severe cases.
- Keeping feet clean and dry, wearing breathable shoes, changing socks daily, and trimming nails straight across can help prevent the infection from spreading.
Importance of Treatment
- Onychomycosis should not be considered a trivial disease, as it can lead to serious complications and affect quality of life 1.
- Treatment can help reduce the risk of complications, improve quality of life, and prevent the spread of the infection to others 1.
From the FDA Drug Label
The optimal clinical effect is seen some months after mycological cure and cessation of treatment due to the time period required for outgrowth of healthy nail. The FDA drug label does not answer the question.
From the Research
Possible Causes of Thickened and Discolored Great Toenail
- Onychomycosis, a fungal infection of the nail, is a common cause of thickened and discolored toenails, particularly in the elderly 2, 3.
- The most common fungi responsible for onychomycosis are dermatophytes, such as Trichophyton rubrum, which can cause distal-lateral subungual onychomycosis, leading to thickening and discoloration of the nail 2, 3.
- Other fungi, such as Candida and non-dermatophyte molds, can also cause onychomycosis, particularly in people with compromised immune systems or underlying medical conditions 2, 4, 5.
- Leukonychia, or white discoloration of the nail, can be a symptom of onychomycosis, particularly superficial white onychomycosis caused by Trichophyton mentagrophytes 2, 3.
Risk Factors for Onychomycosis
- Age: Onychomycosis is more common in older adults, with a prevalence of nearly 20% in patients over 60 years old 3.
- Diabetes: People with diabetes are at increased risk of developing onychomycosis, particularly if they have poor circulation or nerve damage 2, 3.
- Peripheral vascular disease: This condition can increase the risk of onychomycosis by reducing blood flow to the nails 3.
- Trauma: Repeated minor trauma to the nail can increase the risk of onychomycosis 2.
Treatment Options for Onychomycosis
- Terbinafine is a commonly used oral antifungal medication for the treatment of onychomycosis, particularly for dermatophyte infections 3, 4.
- Topical antifungal medications, such as efinaconazole, can be effective for mild to moderate onychomycosis, particularly for superficial white onychomycosis 6.
- Debridement, or removal of the infected nail tissue, can be used in combination with antifungal medications to improve treatment outcomes 3.