Dermatophytes: The Cause of Nail Fungus

Fungal nail infections are a common problem affecting about 1 in 10 adults. The medical term for such infections is onychomycosis, and they are typically caused by fungi known as dermatophytes.

What are Dermatophytes?

The word dermatophyte comes from the Greek terms derma, meaning skin, and phytos, meaning plant. Dermatophytes do not fall under a specific biological classification. The term is a general label for pathogenic fungi capable of growing on skin and causing skin disease. Dermatophytes fall under the genera Trychophyton, Epidermophyton, and Microsporum.

How do Dermatophytes Affect the Nail?

Dermatophytes attack the nails where they consume keratinized material. As the fungi metabolize keratinized tissue, they produce toxic byproducts which result in the inflammation of the host tissue. The fungal colony continues to grow and reproduce as it nourishes itself, in turn increasing the rate at which it degrades the structure of the nail. The body attempts to repair this damage by increasing the rate at which it builds keratin, thus, resulting in thickening of the nail. In some cases, the nail becomes too weak to support itself, occasionally falling off in the process.

Symptoms and Signs

The symptoms and signs of nail fungal infections are often painless and can go unnoticed. This makes it difficult to determine whether you have the fungal infection or not. Nonetheless, there are certain signs that can show you have a dermatophyte fungal infection of the nail.

• Thickening of the nail: When a fingernail or toenail is damaged, the body attempts to repair the tissue by creating more keratin. This results in thicker nails.

• Weakening of the nail structure: Despite the thicker appearance, infected nails often have weaker supporting structure than healthy nails. Dermatophytes tend to make the nails very brittle. Sometimes, infections can become so severe that the nail breaks off entirely.

• Discoloration: Fungal infections can cause discoloration. This is the most evident sign of onychomycosis, but should not be misdiagnosed for other conditions such as nail psoriasis. Discoloration due to infection is often co-morbid with a strong, foul odor.

Symptoms of Fungal Nail Infection Based on Subtype

Depending on the exact location and the degree of the nail fungal infection, the signs and symptoms you experience are divided into subtypes.

• Distal lateral subungual onychomycosis (DLSO): This happens if the nail appears thick, slightly raised, seems unusually hard and has a cloudy appearance. The tip of the nail may appear eroded and brittle with a certain discoloration.

• Endonyx onychomycosis (EO): This occurs when the nail has a discoloration that seems milky white. In this condition, the nail does not separate from the bed and does not thicken or harden.

• White superficial onychomycosis (WSO): With the main affected area being the toe nails, white powdery patches are visible on the nail plate. Nails are rough and crumble easily.

• Proximal subungual onychomycosis (PSO) & total dystrophic onychomycosis: In the former, the nail plate becomes white near the cuticle and remains normal at the end. In the latter, the entire nail plate is affected and may become opaque and have a yellow-brown or greenish-brown to black color. Both are relatively uncommon in comparison to other forms of onychomycosis, but may follow trauma or injury to the nails or nail bed.

Other Organisms that Cause Nail Fungus

Besides dermatophytes, there are other microorganisms that cause fungal infections of the nails. These include:

• Yeasts: Fungal nail infections that result due to yeast impact not only finger and toe nails, but also the tissue that encircles the nail. Yeasts cause nearly eight per cent of all fungal nail infections.

• Non-dermatophyte molds: These organisms are the predominant leading cause of nail fungus in people suffering from HIV. They result in one to 10 per cent of all nail fungal infections. A good example of non-dermatophyte mold is Scopulariopsis brevicaulis.

How to Avoid Growth of Dermatophytes and Nail Fungus?

Prevention is better than cure when it comes to all diseases, including dermatophyte-induced nail fungus. Here are few preventive habits that can keep nail fungus at bay:

• Wear rubber gloves that protect your hands from overexposure to water, as moist atmosphere can be a breeding ground for fungi.

• Wash your hands and feet frequently with soap water, making sure you scrub in between the toes.

• Cut your fingernails and toenails regularly. Do not cut them too short as you can damage the tissue and provide an entry to fungal spores. Do not share nail clippers or files with other people.

• Wear socks that absorb sweat, and choose open-toe shoes to reduce clamminess. Discard old worn-out shoes.

• Make use of anti-fungal spray or powder for the insides of your shoes.

• Desist from wearing artificial nails and nail polish as they create an environment that is perfect for the proliferation of nail fungi.

Treating Dermatophytes and Nail Fungus

When it comes to treating dermatophytes, the treatment varies from person to person as it is dependent on the severity of the infection. It usually involves removing the affected nail or using anti-fungal medicines, creams or gels.

1.  Topical Treatment: With the use of medicated nail polish or nail cream, you can either paint in and around the infected area, depending on the doctor’s directions. You can also use anti-fungal cream, rubbing it into the infected nails after a thorough soak. Many topical products do not require prescriptions. They are usually the first choice of treatment after home remedies are deemed ineffective.

2. Surgical Treatment: Depending on the severity of the nail fungus, your doctor may advise you to go in for a nail avulsion, which involves removing part of the nail or the entire nail. This procedure is carried out after numbing the affected digit with lidocaine. Surgical treatment is often seen as a last resort. This is due to the cost, as well as the rarity of occurrence of infections requiring it.

3. Oral Treatment: Several prescription anti-fungals are available as orally administered treatments. Doctors may recommend these drugs only if topical treatments prove unsuccessful because anti fungal medications can put enormous strain on the liver. Despite this, they remain an effective means of curing fungal nail infections when dosage is properly observed.

4. Non-invasive Treatment:

   a. Laser Treatment: The US Food and Drug Administration (FDA) has approved laser treatment to get rid of nail fungus caused by dermatophytes for the efficient treatment of nail fungus. The laser literally burns off fungi and cauterizes damaged tissue in the area with focused light and heat.

   b. Use of Chemicals: Another method is chemically removing the nail with urea paste which is ideal for patients suffering from diabetic neuropathy, heart diseases, HIV/AIDS and cancer. The urea dissolves the connection between the nail plate and nail bed, making it easier to remove the diseased portion of the nail without any surgical intervention. The underlying healthy nail is left untouched. However, using urea paste takes time (up to a week), and you may also experience irritation of the surrounding soft tissue.

Recommended Nail Fungus Treatment

While dermatophyte-induced nail fungal infection is not life-threatening, it can have a profound effect on your self-esteem and self-confidence. The best nail fungus treatment is the one that clears the infection and allows you to once again have healthy and beautiful-looking nails. You may have to use several treatment options before you find one that eliminates dermatophytes effectively. For more information, visit The Global Nail Fungus Organization’s comparison chart outlining the most effective antifungal treatments available.