Onychomycosis (Nail Fungus) and Athlete's Foot: Treatments and Duration | A Dermatologist Explains the Difference Between Oral and Topical Medications and Why Over-the-Counter Drugs May Not Work

"I keep applying over-the-counter athlete's foot medicine, but it's not healing." "My nails have turned yellow and become thick." "I'm infecting my family with athlete's foot." — Athlete's foot is an infection caused by dermatophytes and will not be cured without proper treatment. In particular, nail fungus cannot be cured with over-the-counter medications, and prescription medication from a dermatologist is essential.

👉 Same-day visits without an appointment are also possible. Please feel free to consult us first.

Differences between Athlete's Foot and Tinea Unguium

Reasons why over-the-counter medicines don't work

• Insufficient application or duration – Stopping medication when symptoms disappear leads to recurrence. It needs to be continued for 1-2 months even after symptoms disappear.

• Topical medications are less effective for nail fungus – Nails have a high penetration barrier, so over-the-counter creams cannot reach the dermatophytes inside the nail.

• Another condition that is not athlete's foot – Nail discoloration and deformation can also occur due to nail psoriasis, trauma, or lichen planus. If over-the-counter antifungal medications continue to be used without effect, this is often the case.

• Source of infection remains – Sharing bath mats and slippers can lead to reinfection.

Diseases that can be mistaken for nail fungus/tinea unguium

Nail discoloration and deformation can occur due to diseases other than tinea unguium (nail fungus). One reason why "over-the-counter medications don't work" is that it might not be tinea unguium in the first place. Self-diagnosis without microscopic examination can delay treatment.

Disease	Nail Appearance	Difference from Tinea Unguium
Tinea Unguium (Nail Fungus)	Cloudy white, yellow, or brown, thickens, becomes brittle	Caused by dermatophytes. Antifungal agents are effective.
Nail Psoriasis	Pitting, oil drop discoloration, nail separation	Dermatological condition. Treated with steroids, etc. Antifungal agents are ineffective.
Nail Lichen Planus	Thinning nails, vertical ridges, pterygium formation	Autoimmune disease. Antifungal agents are ineffective.
Yellow Nail Syndrome	Entire nail yellow, thickened, growth stops	Related to lymphatic and respiratory diseases
Traumatic Nail Deformity	Discoloration/deformity in only 1-2 nails	Caused by bruising or shoe friction
Nicotine Staining	Yellow-brown discoloration	Staining due to smoking. No dermatophytes.

Microscopic examination (collecting a sample of the nail or skin to check for dermatophytes) can be performed on the day of your visit.
Please feel free to consult us even if you are unsure whether you have nail fungus.

Dermatological treatment for tinea unguium – differences between oral and topical medications

Oral medication is the most effective treatment for nail fungus. However, it can affect liver function, so regular blood tests are required.

Frequently Asked Questions (FAQ)

Q. I'm not sure if I have athlete's foot, can I get it checked?

Yes. We will accurately diagnose whether you have athlete's foot with a microscopic examination (taking a small sample of your skin to check for dermatophytes). If it's a different condition with similar symptoms (such as eczema or psoriasis), the treatment method will differ, so we recommend seeing a doctor rather than self-diagnosing.

Q. Can nail fungus be treated with insurance?

Yes, if diagnosed with tinea unguium, oral and topical medications can be prescribed with insurance coverage.

Q. I'm worried about the side effects of oral medication...

Oral antifungal medications can affect liver function, so we will conduct regular blood tests during treatment. Please inform us beforehand if you have liver disease or are taking other medications. Most people can complete the treatment without problems.

Q. I've infected my family. What should I do?

It is important for all family members to receive treatment simultaneously. Also, stop sharing bath mats and slippers, and keep the bathroom clean to prevent reinfection.