Nail Dystrophy vs Onychomycosis: Diagnosis & Treatment

Nail disorders are common and can take many forms, both from birth and as a result of something else. These conditions can change the way your nails look and how they work. Getting the right diagnosis is important so you can get the right treatment.

Two common nail disorders are nail dystrophy and onychomycosis. Nail dystrophy refers to any change in how the nail grows or looks, and it can have many different causes. Onychomycosis, on the other hand, is a fungal infection of the nail, and it’s a frequent cause of nail dystrophy.

It can be tricky to tell the difference between nail dystrophy and onychomycosis. They can look very similar, making it hard to diagnose just by looking at them. If they’re misdiagnosed, you might get the wrong treatment, which can make the problem worse or last longer.

This article provides a complete overview of nail dystrophy and onychomycosis, and will help you understand how to tell them apart, how they’re diagnosed, and how they’re treated. We’ll look at what they look like, what tests can be done, and what treatment options are available for each condition. Knowing the difference between nail dystrophy vs onychomycosis can help you get the care you need.

Nail anatomy and terminology

To really understand nail problems, you need to know a little bit about how nails are put together. The main parts are:

• Nail plate: That’s the hard part you see.
• Nail bed: That’s the skin underneath the nail plate.
• Nail matrix: This is where the nail grows from.
• Lunula: That’s the little white moon shape at the base of your nail.
• Proximal nail fold: The skin that covers about a quarter of the nail.

There are also some key terms to know when talking about nail problems:

• Onycholysis: When your nail plate separates from the nail bed.
• Subungual hyperkeratosis: When keratin builds up under the nail.
• Longitudinal ridges: Vertical lines that run up and down the nail.
• Transverse ridges: Horizontal lines that run across the nail.
• Melanonychia: Dark streaks in the nail.
• Leukonychia: White spots on the nail.
• Paronychia: An infection around the nail.

Knowing your nail anatomy can help you and your doctor figure out where the problem is coming from. Using these terms also helps everyone stay on the same page when discussing nail disorders.

Onychomycosis: A Deeper Dive

Onychomycosis, a fungal infection of the nail, isn’t just a cosmetic issue. It can cause pain, discomfort, and even impact your quality of life. Let’s take a closer look at who gets it, what causes it, and how it’s classified.

Who Gets Onychomycosis?

This infection is surprisingly common. It affects roughly 10% of the general population. It’s also worth noting that it becomes more common as we age. While 10% of the general population is affected, that number jumps to 20% for those over 60 and a whopping 50% for those over 70. That’s a significant increase!

Certain health conditions and lifestyle factors also put you at a higher risk. These include:

• Diabetes (diabetic patients are 1.9 to 2.8 times more likely to develop onychomycosis)
• HIV (prevalence ranges from 15% to 40% in HIV-positive individuals)
• Peripheral vascular disease
• Smoking

What Causes Onychomycosis?

Fungi are the culprits, but not all fungi are created equal. The most common offenders are dermatophytes, which account for 80-90% of cases. These include species like Trichophyton, Epidermophyton, and Microsporum. Nondermatophyte molds cause 2-10% of cases, while yeasts (like Candida) are responsible for 2-11%.

Classifying Onychomycosis: Why It Matters

Onychomycosis isn’t just one single condition. It’s categorized based on how the infection presents itself. The main types are:

• Distal and lateral subungual onychomycosis (DLSO): This is the most common type, affecting the nail bed and spreading inward.
• Proximal subungual onychomycosis (PSO): This starts near the cuticle and moves outward.
• Superficial white onychomycosis (SWO): This appears as white spots on the surface of the nail.
• Total dystrophic onychomycosis (TDO): This is the most severe form, affecting the entire nail and causing significant distortion.

Knowing which type you have is crucial because different types may respond differently to various treatments. What works for one type might not work for another, so accurate classification is key to guiding treatment decisions.

What causes nail dystrophy?

Nail dystrophy is a change in the appearance, texture, or shape of a nail. These changes can happen for many reasons, and it’s not always easy to pinpoint the exact cause. Here’s a rundown of some of the most common culprits:

Trauma

Physical injury is a big one. Nail injuries can range from stubbing your toe to repetitive pressure from ill-fitting shoes. In fact, one type of nail dystrophy, acquired great toenail dystrophy (AGNUS), is so common in shoe-wearing societies that up to 70% of nail dystrophies in these populations are related to trauma.

Non-fungal infections and inflammatory conditions

Sometimes, nail changes aren’t due to a fungus but to other infections or skin conditions like psoriasis, eczema, or lichen planus. These conditions can mess with the way your nail grows and develops.

Systemic diseases and nutritional deficiencies

Believe it or not, your overall health can show up in your nails. Conditions like iron deficiency and thyroid disorders can affect nail growth and appearance.

Drug-induced nail changes

Certain medications can also cause nail discoloration and structural changes. If you notice changes after starting a new medication, talk to your doctor.

Clinical features of nail dystrophy

Nail dystrophy can show up in many ways. You might notice:

• Thickening of the nail
• Discoloration, including the possibility of green fingernail fungus
• Ridges forming on the nail surface
• Pits or small depressions in the nail
• Onycholysis (separation of the nail from the nail bed)
• Crumbling or brittleness of the nail

Different underlying conditions can cause specific nail changes. For example, psoriatic onycholysis (nail separation due to psoriasis) is often used as a reference point when describing other forms of onycholysis. Nail pitting is also frequently associated with psoriasis.

Trauma-induced nail dystrophy

As mentioned earlier, trauma is a common cause of nail dystrophy. AGNUS, specifically, is a frequent culprit, especially in the big toenail.

How to tell the difference between onychomycosis and nail dystrophy

It’s important to get an accurate diagnosis for your nail problems. If you treat nail dystrophy as if it were onychomycosis, the problem may keep coming back, and the treatment won’t be effective.

Also, if you take antifungal medications when you don’t need them, you may experience unpleasant side effects, and the fungi that cause onychomycosis may become resistant to those medications.

Onychomycosis and nail dystrophy can look a lot alike because they both can cause thickening, discoloration, and separation of the nail from the nail bed (onycholysis).

Clinical Examination

A doctor will start by examining your nails. They’ll look at:

• Nail plate thickness
• Color
• Texture
• Whether the nail is separating from the nail bed
• Whether there’s debris under the nail

But you can’t rely on a physical exam alone to know what’s going on with your nails. As many as half of all nail problems aren’t onychomycosis!

Lab tests

To be sure of an onychomycosis diagnosis, your doctor needs to order some lab tests.

Direct Microscopy (KOH preparation)

Before taking a sample, the technician will clean your nail with 70% isopropyl alcohol. Then, they’ll mix your nail scraping with a 10% to 20% KOH solution for examination under a microscope.

Fungal Culture

A fungal culture is the gold standard for diagnosing onychomycosis. It allows the lab to identify the specific type of fungus that’s causing the infection.

Periodic Acid-Schiff (PAS) Staining

PAS staining can make a diagnosis more accurate because it helps technicians see fungal elements more clearly.

Nail Plate Biopsy

A nail plate biopsy can help doctors tell the difference between onychomycosis and nail dystrophy that’s caused by an injury.

If you have an isolated dystrophic nail that hasn’t responded to standard treatment, a biopsy may be the next step. Technicians will look for hyperkeratinization, or thickening, of the nail bed.

Treatment Options

Both onychomycosis and nail dystrophy have treatment options that can improve the look and health of your nails. It’s important to know that results take time, and a completely clear nail is not always possible.

Treatment of Onychomycosis

Onychomycosis treatment focuses on getting rid of the fungal infection.

1. Systemic Antifungal Agents:

   Oral medications like terbinafine, itraconazole, and fluconazole are commonly prescribed for adults. These are often the most effective, but they don’t work 100% of the time. If you take an oral antifungal, your doctor will want to monitor your liver enzymes to make sure the medication isn’t causing any problems.

2. Topical Antifungal Agents:

   Ciclopirox is a topical antifungal. When used on its own, it’s not as effective as oral medication, but it can be helpful when used in combination with systemic treatments.

3. Non-Prescription Treatments:

   There are many non-prescription treatments available, but they have variable results. Some studies show success rates around 50% for products like Renewed Nail and 71%/59% for snakeroot.

4. Physical Treatments:

   Laser and photodynamic therapies are newer options, but there isn’t a lot of evidence to support their use. Nail trimming and debridement (removing damaged parts of the nail) can help repair damaged toenails and improve treatment outcomes.

Treatment of Nail Dystrophy (Non-Onychomycosis)

Nail dystrophy treatment focuses on addressing the underlying cause and improving the nail’s appearance.

1. Addressing the underlying cause:

   This might involve managing conditions like psoriasis or eczema.

2. Topical Treatments for Nail Dystrophy:

   Kerasal and CN-U are topical treatments designed for nail dystrophy. Clinical studies show that a completely clear toenail is rare (less than 12% of patients). However, Kerasal showed noticeable improvements to the nail plate in 65% of patients after 1 week and 82% after 2 weeks.

3. Nail Debridement

   Routine nail debridement is vital to prevent recurrence. Debridement with topical or systemic treatment can increase success.

4. Follow up regularly

   Follow up regularly (every 2 months) to assess nail changes during treatment.

Combination Therapies

Sometimes, the best approach is to combine treatments.

1. Importance of addressing both onychomycosis and underlying dystrophy:

   If you only treat the fungal infection without addressing the underlying nail dystrophy, the infection is likely to come back.

2. Combining systemic and topical antifungals with nail debridement:

   Ciclopirox, while not very effective on its own, can be useful in combination with other treatments or for patients who can’t take oral medications.

Treatment failure and recurrence

Sometimes, treatments for nail problems don’t work, or the problem comes back. Here’s what might be going on and what you can do about it.

Why treatments fail

Treatments can fail for several reasons:

• Misdiagnosis: If you don’t know what’s causing the problem, you can’t treat it effectively. For instance, you might treat nail dystrophy as if it were a fungal infection.
• Resistant organisms: Some fungi just don’t respond to certain medications.
• Not following directions: Topical medications need to be used consistently, and oral medications need to be taken for the whole course of treatment. Otherwise, they may not work.
• Severe damage: Sometimes, the nail is too damaged to heal well, especially if the infection is advanced.

There are also risk factors that can make treatment less likely to work.

How to minimize recurrence

To keep the problem from coming back:

• Address risk factors: Manage conditions like diabetes and improve blood flow.
• Practice good nail and foot care: Trim your nails regularly, wear shoes that breathe, and avoid injuring your nails.
• Consider preventative treatment: After a successful treatment, think about using topical antifungals to prevent another infection.
• Get regular nail cleanings: This can help remove infected parts of the nail.

Frequently Asked Questions

In Conclusion

Nail dystrophy and onychomycosis can both cause changes to your nails, but they’re different things. Nail dystrophy describes a whole group of conditions that change the way your nails look and feel. Onychomycosis is a specific type of fungal infection.

Because they can look similar, it’s important to get the right diagnosis. Your doctor may need to do lab tests to figure out exactly what’s going on with your nails.

Once you have a diagnosis, you and your doctor can decide on the best treatment plan for you. If you have nail dystrophy, your treatment will focus on what’s causing it. If you also have a fungal infection, you’ll need treatment for that, too.

Researchers are constantly working to find new ways to diagnose and treat nail problems. Future research could lead to better treatments and ways to prevent these conditions from coming back.

No matter what’s going on with your nails, it’s important to take good care of them and follow your doctor’s instructions. With the right care and treatment, you can improve the health and appearance of your nails.