Fungal Nail Infection: Symptoms, Causes, and Best Treatment Options

What is a Fungal Nail Infection (Onychomycosis)?

A fungal infection of the nail unit is known medically as onychomycosis. The condition occurs when fungal organisms invade the nail structure, making it different from other nail problems. The infection can cause serious complications like cellulitis, tissue damage and nail loss when patients don't seek treatment.

These infections stem from three distinct types of fungi:

• Dermatophytes: These fungi cause 90% of toenail & 50% of all fingernail infections.

• Yeasts: The organism Candida albicans mostly affects fingernails.

• Nondermatophytic moulds: Species like Fusarium and Aspergillus cause nail infections.

People experience toenail infections more often than fingernail infections. The reason lies in our footwear - shoes create warm, moist environments where fungi thrive. 

Types of Fungal Nail Infection

Nail fungal infections exist in several distinct forms. Doctors categorise these infections by their starting point and their effects on the nail.

• Distal and lateral subungual onychomycosis: This is the most common infection, starting at the nail's tip or sides and creating yellow or brown discolouration that moves inward. The nail becomes thicker and brittle, and it might separate from the underlying bed.

• White superficial onychomycosis: This shows up as white patches on the nail's surface. These spots have distinct edges that eventually cause the nail to crumble and develop pits. Toenails face this problem more often than fingernails.

• Proximal subungual onychomycosis: A rare condition begins near the cuticle. White spots appear and spread outward as the nail grows. This variant typically signals immune system issues (particularly in patients with HIV).

• Endonyx onychomycosis: This causes a milky-white discolouration throughout the nail. This uncommon form differs because fungi invade the inner nail layers without causing thickening or separation.

• Candidal onychomycosis: This yeast infection mainly targets fingernails. The infection's signs include cuticle redness and nail discolouration that varies from white to green or black.

• Total dystrophic onychomycosis: This causes complete nail destruction.

Signs & Symptoms of Fungal Nail Infection

Nail fungal infections don't show their symptoms right away. You might notice just a tiny white or yellow spot under your nail at first. The discolouration spreads to your entire nail as time passes, and your nail could turn white, yellow, green or even black.

These fungal infections usually show up on toenails, but they can affect your fingernails too. Your nails might show these changes:

• They become much thicker and harder to trim

• They turn brittle and break apart easily

• They start curling up or down instead of growing straight

• They begin to separate from the skin underneath

• They give off an unpleasant smell

• They look twisted or misshapen

The early stages rarely hurt, but advanced infections can make walking painful because of the pressure on affected areas. The skin around your nails might get red and sore without treatment.

These infections affect more than just your physical health. Many people feel self-conscious about how their nails look. This emotional toll hits harder if the infection affects visible fingernails rather than hidden toenails.

Causes & Risk Factors

Tiny organisms can work their way under your nail and cause fungal infections. These pesky fungi typically sneak in through small cuts or cracks in your skin or nails.

Dermatophytes cause about 90% of these infections. These moulds feed on keratin, the protein that makes nails hard. Your chances of getting this condition go up due to several factors:

• Age: The risk goes up a lot with age and affects many people over 70

• Medical conditions: You're more likely to get infected if you have diabetes, poor circulation, or psoriasis

• Lifestyle factors: Your feet get exposed to these fungi when you walk barefoot in public showers, pools, and locker rooms

• Physical factors: Your fingers or toes create perfect growing spots when they stay moist too long

• Related infections: Athlete's foot makes you more than twice as likely to get infected

• Body weight: Research shows that carrying extra weight increases your chance of onychomycosis by a lot

The infection hits men harder than women. Children rarely face this problem.

Living with someone who has a nail infection raises your risk substantially. Closed-toe shoes create warm, damp spaces where fungi love to grow.

The risk jumps up by a lot if you have a weakened immune system, especially with conditions like HIV.

When to Seek a Doctor

Fungal nail infections need proper treatment to avoid serious health issues beyond just appearance. 

Contact your doctor if:

• Your nails hurt or cause major discomfort

• The nail colour changes to brown or black

• Your nail starts separating from the skin underneath

Medical help becomes crucial if you have:

• Diabetes - even small nail infections can be risky

• A weak immune system - especially when you're getting chemotherapy or have had an organ transplant

• Poor blood circulation

Complication

Leaving these infections untreated might lead to:

• Cellulitis - a dangerous skin infection that needs urgent care

• Lasting nail damage or deformity

• Your nail falling off completely

• Damage to tissue or bone infection (osteomyelitis)

Diagnosis of Fungal Nail Infection

Doctors check your nails and collect samples by scraping debris from underneath them. They test these samples in several ways:

• Potassium hydroxide (KOH) smear gives quick results

• Fungal culture identifies the exact cause but takes weeks

• Nail clipping analysis helps confirm diagnosis

Treatment Options 

Oral medications are the quickest way to see results:

• Terbinafine: Daily doses last 6 weeks for fingernails or 12 weeks for toenails

• Itraconazole: Doctors prescribe this in pulse therapy

• Fluconazole: Doctors use this option less frequently

Topical treatments show better results in mild cases:

• Efinaconazole 10% solution: Complete cure rates reach up to 17.8%

• Ciclopirox 8% nail lacquer: Daily application continues for up to 48 weeks

Surgical approaches help patients when medications don't work:

• Nail avulsion (partial or complete removal)

• Nail debridement reduces thickness

Laser therapy delivers promising results with minimal side effects. This option works great for patients with liver or kidney conditions.

Prevention and home-care strategies

• Your nails should stay short, dry, and clean. 

• Choose breathable footwear and moisture-wicking socks. 

• Antifungal powders help protect shoes and feet. 

• Personal items like nail tools, shoes, and towels should never be shared.

How to Avoid Recurrence

Many successfully treated patients face recurrence within a year. 

You can avoid this by treating tinea pedis early, getting new footwear, using UV light or ozone to disinfect shoes and applying maintenance antifungal treatments.

Myths & Frequently Misunderstood Facts about Fungal Nails 

People often misunderstand nail fungal infections, which leads to confusion about their causes, treatment, and prevention. Here's a table that separates common myths from the real facts:

FAQs

1. What causes fungal nail infections?

   Tiny organisms called fungi cause nail infections. These microbes get into your nails through small cracks in your nail or skin. They love warm, moist places like swimming pools and showers. You can get these fungi by touching someone who has an infection or using their towel.

2. What are the common symptoms of a fungal nail infection?

   The first sign is usually a small discoloured spot under your nail tip. You might notice these changes as time goes on:

   • Yellow, brown, or white spots that spread

   • Nails become thick, brittle, or crumbly

   • Nail shape changes

   • Slight odour develops

   • Debris collects under the nail

   • Nail starts separating from the nail bed in advanced cases

3. How can I tell if I have toenail fungus or something else?

   Many conditions look like fungal infections. Nail psoriasis shows small dents on the nail surface and oil drop-like discolouration. Fungal infections start at the nail tip or sides, and your nail gets thicker and yellower over time. Psoriasis affects multiple nails at once and comes with skin symptoms in other body parts. A doctor can run tests to know for sure.

4. Who is most at risk of developing a fungal nail infection?

   Age plays a big role - about 50% of people over 70 get these infections. Your risk goes up if you:

   • Are male

   • Have diabetes, poor circulation, or psoriasis

   • Walk barefoot in public showers and pool areas

   • Wear tight shoes that make feet sweat

   • Have a nail injury or bunion

   • Live with someone who has a fungal infection

   • Have athlete's foot

5. How are fungal nail infections diagnosed?

   Doctors look at your nails and take samples from underneath. Laboratory testing analyses these samples through methods like potassium hydroxide (KOH) smear or fungal culture to identify specific fungi. Identifying the right cause is important because other conditions (psoriasis, lichen planus & nail injuries) prima facie look similar to fungal infections.

6. What treatments are available for fungal nail infections?

   Treatment depends on how bad the infection is. Oral antifungal medications like terbinafine and itraconazole work best. These medications help grow a new, healthy nail to replace the infected part over six to twelve weeks. You can also use medicated nail polish with ciclopirox or antifungal creams. Severe cases might need temporary nail removal or laser treatments.

7. How long does it take for a fungal nail infection to heal?

   Your body needs 12-18 months to grow a completely new toenail that replaces the infected one. The healing process moves through different stages:

   • Early stage: 4-6 weeks

   • Moderate stage: 2-3 months

   • Advanced stage: After 6 months

   • Chronic stage: Beyond 1 year

   You won't see results right away. Most patients wait several months before noticing visible improvements, even with the right medication.

8. Can fungal nail infections come back after treatment?

   In fact, about 20-25% of successfully treated patients experience a recurrence. Patients using itraconazole face more relapses compared to those using terbinafine.

9. How can I prevent fungal nail infections from spreading or recurring?

   Regular maintenance after treatment reduces the chance of recurrence. Here's what you can do to prevent infections:

   • Treat athlete's foot quickly

   • Throw away or sanitise old shoes

   • Use antifungal powders as protection

   • Keep your feet dry and cool

   • Wear flip-flops at public pools and gyms

   • Make sure everyone at home gets treatment if infected