Nail Fungus (Onychomycosis): Diagnosis and Treatment

What is Nail Fungus?

Onychomycosis is an infection of the nail plate and nail unit with fungi. It most commonly occurs in toenails; however, it can also affect fingernails.

In the nail:

Yellow, white, or brown discoloration,

thickening,

breakage and crumbling,

keratin accumulation under the fingernails,

separation of the nail from the nail bed

This can lead to changes such as these.

However, the first and most important point is this:

Not every thick, yellowed, or damaged nail is a fungal infection.

Psoriasis, trauma, lichen planus, and other nail diseases can resemble onychomycosis. Therefore, it is important to confirm the diagnosis as much as possible, especially if oral antifungal treatment is being considered.

Briefly, what you need to know

Onychomycosis is not just a cosmetic problem.

Not every nail disorder is a fungal infection.

It can occur together with athlete's foot.

Because nails grow very slowly, treatment and results can take months to appear.

Topical treatments are not sufficient for every patient.

Oral antifungals are more effective in some patients, but they are not suitable for everyone.

Even if the treatment is successful, it takes a long time for a healthy nail to fully grow back.

Recurrence may occur.

We will not equate laser and device therapies with standard drug therapies in terms of evidence level.

What causes nail fungus?

The most common causes of onychomycosis are dermatophytes. However, some yeasts and non-dermatophyte mold fungi can also cause nail infections.

Trichophyton rubrum is one of the most common dermatophytes, especially found on toenails.

Risk;

old age,

accompanying athlete's foot,

nail trauma,

prolonged humid/enclosed shoe environment,

some circulatory problems,

diabetes,

suppression of immunity

It may increase in situations such as these.

Are athlete's foot and nail fungus related?

Yes.

Tinea pedis (athlete's foot) and onychomycosis can frequently occur together.

Treating only the nail and leaving dermatophyte infections between the toes or on the soles of the feet untreated can create problems for reinfection.

Therefore, during the examination:

nails + spaces between toes + soles of feet

They should be evaluated together.

All yellow nails are due to nail fungus.

No.

Conditions that may resemble onychomycosis include:

nail psoriasis,

repetitive trauma,

onycholysis,

lichen planus,

some bacterial infections,

age-related nail changes

It can be found.

Traumatic nail changes can easily be mistaken for fungal infections, especially in people who constantly wear tight shoes.

For this reason:

“"Yellow nails → start antifungal medication."”

The decision to reapply should be based not only on the passage of time, but also on current anatomy and clinical need.

How is nail fungus diagnosed?

Clinical appearance may suggest a diagnosis; however, a nail sample can be taken to demonstrate the presence of the fungus if necessary.

Possible methods include:

KOH direct microscopy,

fungal culture,

histopathological examination/PAS,

molecular methods under suitable conditions

It is found.

The sensitivities and advantages of the tests vary; sometimes a single negative test may not completely rule out a fungal infection.

Sampling from the correct area of the fingernail also affects diagnostic success.

Why do we conduct tests?

Because systemic antifungal treatment can last for weeks or months, it's important to avoid unnecessary medication.

Especially if the clinical presentation is atypical or if oral treatment is planned:

First, are there really any mushrooms?

Answering that question is valuable.

Furthermore, in resistant or recurrent cases, identifying the causative organism can influence treatment decisions.

Are there different types of onychomycosis?

Yes.

The most common form is distal lateral subungual onychomycosis. Infection usually begins at the tip and side of the nail.

Apart from that:

superficial onychomycosis,

proximal subungual onychomycosis,

Endonyx onychomycosis,

total dystrophic onychomycosis

Clinical patterns such as these may be observed.

These clinical patterns can influence treatment planning during dermatological evaluation.

How is nail fungus treated?

When choosing a treatment:

Number of nails affected + proportion of the nail affected + matrix involvement + nail thickness + causative agent + accompanying diseases

They are evaluated together.

Therefore, the same fungicide is not given to everyone.

Topical antifungal treatments

In localized onychomycosis, antifungal preparations applied to the nail can be used.

A significant disadvantage of these is that the nail plate makes drug penetration more difficult.

Treatment is usually long-term and requires regular application by the patient.

Therefore, topical treatment:

“"If it doesn't last a week, it's useless."”

It should not be evaluated in this way.

Oral terbinafine

In dermatophyte-related onychomycosis of the toenail, oral terbinafin is one of the most potent and established systemic treatment options.

Especially:

When multiple nails are held together,

When a large section of the nail is affected,

When matrix retention occurs,

when there is significant thickening

Systemic treatment may be more meaningful.

However, oral terbinafin is not automatically started for every patient.

Drug interactions, history of liver disease, and other individual factors should be evaluated.

Itraconazole

Itraconazole is another systemic antifungal option that can be used in onychomycosis.

The causative organism, the patient's health status, other medications being used, and treatment history all play a role in the selection process.

Because itraconazole can have significant drug interactions, it is necessary to know what medications the patient is currently taking.

Does filing or thinning nails help?

Mechanical thinning of thickened nails can have the following effects on some patients:

It can reduce the pressure,

It can provide ease of maintenance.,

It can help increase the penetration of topical treatment.

However, debridement alone is not an antifungal treatment that cures the fungus.

Should the nail be removed completely?

It's usually not the first approach.

Although destructive methods were more frequently used in the past, routine removal of the entire nail is not necessary for most patients in the modern management of onychomycosis.

In selected and problematic cases, surgical or chemical nail avulsion may be considered as an adjunct method.

Can laser treatment cure nail fungus?

This is the section where we will remain particularly focused on scientific research.

In the treatment of onychomycosis:

Nd:YAG,

diode,

other laser and energy systems

It has been researched.

While some studies have reported clinical improvement, study protocols, equipment used, outcome measures, and follow-up periods are quite heterogeneous.

Because:

“"Laser treatment definitely cures nail fungus."”

This means going beyond the available evidence.

Laser/energy-based methods may be considered as adjunctive options in selected situations; however, the level of evidence does not support their automatic replacement for established antifungal treatments.

This approach is also consistent with our site-wide principle:

We don't follow the logic of "we have the device → let's recommend it to everyone.".

Why does the treatment take so long?

Because nails grow very slowly.

Even if the fungal infection is microbiologically controlled, a damaged nail will not instantly return to normal.

The new, healthy nail needs to grow and replace the old, damaged area.

In particular, it can take approximately 12–18 months for a large toenail to completely regenerate.

“"I took the medication, but my nail is still yellow."”

It doesn't always mean the treatment has failed.

It's important to observe how the nail grows from the base.

How do we know if the treatment was successful?

One of the most important clinical signs is the growth of a healthy, more normal-looking new nail from the proximal part, or base, of the old nail.

Over time, this healthy phase progresses.

If necessary, mycological examinations can also be used to evaluate the response to treatment.

Why does nail fungus recur?

Recurrence and reinfection are possible in onychomycosis.

To this:

persistent athlete's foot,

infected shoe/sock environment,

nail trauma,

failure to complete treatment,

person's predisposition

can contribute.

Therefore, it is not correct to treat only the nail and leave the accompanying tinea pedis untreated.

Should we throw away the shoes?

It's usually not necessary to throw away all your shoes.

But:

keeping feet dry,

Changing socks regularly,

Using the shoes alternately to allow them to dry,

avoiding sharing nail clippers/files

It can help reduce the risk of reinfection.

Can I cover it up with nail polish or artificial nails?

Cosmetic closure does not treat the underlying infection.

Additionally, prolonged occlusion, nail trauma, or treatments can worsen nail problems in some individuals.

The suitability of cosmetic procedures during treatment should be evaluated according to the patient's condition.

Is nail fungus contagious?

Infection is possible.

However, not everyone living in the same household necessarily develops an infection.

Partner:

nail scissors,

file,

towel,

some foot care tools

It should not be shared.

Can it be transmitted through manicures and pedicures?

Inadequately sterilized or shared instruments can contribute to the transmission of infections.

This is important not only for fungal infections, but also for other infections.

Therefore, proper hygiene and sterilization are important in nail care.

Why is it even more important for diabetic patients?

Onychomycosis is more common in people with diabetes.

Especially accompanying:

peripheral neuropathy,

circulatory problems,

foot deformity

If present, nail thickening and infection can lead to more significant clinical consequences.

In these patients, aggressively cutting the nails at home or attempting to treat them with chemical products can increase the risk of trauma and injury.

Can vinegar, baking soda, or tea tree oil work at home?

These kinds of methods are frequently recommended online.

However, there is no strong clinical evidence to support their effectiveness in established onychomycosis at the same level as standard antifungal treatments.

Additionally, some products can cause irritant or allergic contact dermatitis.

Therefore, we will not replace scientific treatment.

When should you consult a dermatologist?

Especially:

If your nails are getting thicker and thicker,

If more than one nail is affected,

If it separates from the nail bed,

if pain develops,

If it doesn't improve despite treatment,

If you are not sure that the diagnosis is really a fungal infection,

if there is diabetes or immunosuppression,

if oral antifungal treatment is being considered

Dermatological evaluation is appropriate.

Frequently Asked Questions

Is every yellow nail a fungal infection? No. Psoriasis, trauma, and other nail diseases can create a similar appearance.

Are there tests for nail fungus? Yes. KOH microscopy, culture, PAS/histopathology, and molecular methods in appropriate cases can be used.

Can nail fungus be treated with cream? Topical treatment may be sufficient for some localized infections; systemic treatment may be necessary for widespread or matrix-affecting disease.

What is the most effective medication for nail fungus? In dermatophyte onychomycosis, oral terbinafin is one of the most established and effective systemic options. However, the causative agent, the patient's health status, and drug interactions can alter the treatment choice.

Can laser cure nail fungus? There are positive studies with laser and energy-based methods, but the evidence is heterogeneous. It should not be considered a definitive treatment to be recommended to everyone as an alternative to standard antifungal treatments.

Does nail fungus completely go away? Successful treatment is possible; however, it takes a long time for the healthy nail to be fully visible again, and recurrence is possible.

Will having my toenail removed cure the fungal infection? Toenail removal alone does not eliminate the biological cause of the infection and is not a routine first treatment for most patients.

Can fungus reach the root of the nail? The nail matrix can be affected by infection; however, the commonly used term "fungal root" is not anatomically accurate.