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Introduction

Have you noticed that one or more of your toenails are growing up rather than out? Perhaps one or more of your toenails are turning color? You may have the most common toenail complaint in America—Onychomycosis. Onychomycosis is a fungal infection of the nail plate affecting 2 to 18% of the American population accounting for up to 50% of all nail disease [1-3]. Left untreated, some fungal nails can grow thick enough to cause pain, both literally and psychologically. Though many treatment options are available, none can truly guarantee the return of a normal nail.

Healthy Nails

Normal healthy nails appear clear where they are not adhered to the skin and pink where they are attached to the skin. The surface of the nail plate is smooth and thin (about one mm) with only a mild curvature at the sides. Nails are composed of a substance called keratin, similar to that in skin and hair, only harder because of less water content within the nail. They are a hard, resilient structure whose main function is to protect the blood vessels, nerves and bones underneath [4].

Toenails grow from an area, called the matrix, which lies underneath the cuticle. Any disturbance to this matrix may cause nails to grow abnormally; rather than being smooth and flat, they may project upward, grow with lines, grooves, pits, discoloration, or thickening [5]. Because the toenails grow slowly, about 0.05-mm/day, growing a new toenail can take 3 to 9 months [4].

Fungal Nails

If one or more of your toenails appear thickened and discolored, they may be infected by a fungus. Fungal nails, or onychomycosis, are not only unattractive; they can be painful, too. There are many different types of fungus that can invade the nail plate. A fungus is a microscopic organism that grows best in warm, dark, moist environments, like socks and shoes. It eats away at the layers of the skin and nails. Athlete’s foot (a fungal infection of the skin), medical conditions such as diabetes, poor blood flow, or decreased immune status can welcome a fungal infection into the nails.

Signs and Symptoms

The fungal infection generally starts in a single toenail and progresses to adjacent nails over time. A portion of or the entire nail will have a yellow, white, or brownish discoloration with thickening of the nail plate and crumbly debris underneath. Increased thickness of the nail can cause increased pressure on the toes while wearing shoes or when walking. The infected nail may separate from the underlying skin of the nail bed, or pinch into the skin surrounding the nail, which can lead to secondary bacterial infection. Fungal nails are often very difficult to trim and require the assistance of a foot and ankle specialist.

Treatment

Clearing the nails of fungus can be a long and frustrating process. First, you should be certain that your condition is indeed a fungal infection. Although nearly 50% of all nail conditions are of a fungal etiology, a proper diagnosis is needed since many nail conditions look alike. Other processes, such as psoriasis, aging, or injury can have a similar appearance [6]. Your podiatrist will inspect the nails and may take a sample for lab testing. Treatment of mycotic (fungal) nails consists of trimming difficult to cut nails, grinding down the thickness of the nails, removing the entire nail, and/or use of antifungal medications.

Topical Medications: From the Outside In

Until recently, topical antifungals were all available over-the-counter. Although as convenient as painting your toenails, these medications are, for the most part, ineffective at curing fungal nails. This is not to say that they do not work, but their likelihood of success is small (<10%). These medications can help control the spread of the fungus, but often will not eliminate it completely or permanently. Why? Simply because these medications are not strong enough to penetrate the entire thickness of the nail. Additionally, as is the case with all antifungal medications, it takes several months before noticeable results can be seen (you may recall that it can take upwards of 10 months to grow a toenail).

Recently, the FDA approved a prescription-strength topical antifungal agent for treating onychomycosis. Penlac lacquer (Ciclopirox 8%) offers a more effective alternative than the traditional topical medications. Though more powerful than over-the-counter topical medications, Penlac’s cure rate is still only 34% [7].

Oral Medications: From the Inside Out

Sporanox and Lamisil are the two most frequently used oral antifungals. These medications are very effective (54% to 70% cure rate) because they work by traveling through the blood stream to the infected nail. They protect the newly growing nail from being invaded by fungus and control the current infection until a full-grown healthy nail replaces it. Again, nail growth is slow and fungal infections are stubborn; this treatment takes time. The oral medications need to be taken for 3 to 4 months, but remain active within the body for another 6 to 9 months after the medication is discontinued. The downside of these medications is that they can be somewhat expensive. They may also interact with other medications that are being taken, such as antihistamines, cholesterol lowering drugs, benzodiazepines, or drugs used for peptic ulcers. Before beginning treatment with oral antifungals, a blood test is necessary to monitor the function of your liver. In rare instances, these medications can cause liver disease. Other side effects include headache, taste disturbance, stomach upset, dizziness, and skin rash [8]. Many doctors are combining oral and topical medications to maximize the chance of cure.

Removing the Nail

Complete avulsion, or removal of the nail plate is another option for treating onychomycosis. This relatively simple procedure can be done in the office. Your doctor will numb the toe and remove the nail with sterile instruments. After the procedure, the toe may appear unusual until a new nail grows out. Either a topical or an oral antifungal can be used following the procedure to ensure that the new nail that grows will be free of infection; however, no guarantees can be made. Some patients elect to have their nail(s) permanently removed—applying a chemical to the nail matrix after the nail has been removed does this. A thin layer of skin will grow in the nail’s place, and if you paint your toenails, this layer of skin will appear like a normal nail—no one will notice that the nail is missing. There is about a 10% chance that the nail will grow back despite chemical destruction.

Complication of Onychomycosis

Hematoma formation (pooling of blood) underneath the nail can occur as a result of physical demands on the feet during sports and other high impact activities. Blood accumulation may be the result of pressure against the toe from a thickened fungal nail or may occur after blunt trauma to the nail. An x-ray will determine if there is a fracture to the bones of the toe. If a laceration to the nail bed is suspected, the toenail will have to be removed for inspection and repair of any open wounds. Otherwise, a small hole in the nail plate can be made to relieve pressure from the accumulated blood.

Soaking the foot will cleanse the area of dried blood and prevent infections. Often, the injured nail will fall off on its own and the sensitive nail bed will become covered with hardened skin. If there is no injury to the bones of the foot, normal activities can be continued. Within 3 to 9 months, a new nail plate will fully replace the missing nail. However, because damage may have been done to the nail matrix, this new toenail may not necessarily grow in normally.

Conclusion

If unattractive fungal nails embarrass you, see your podiatrist to discuss the most effective treatment for your problem. A plethora of options are available from topical medications to oral medications to just getting rid of the nail. To prevent infection and/or reinfection, keep your feet dry and free from injury. Wearing cotton socks will draw moisture away from the feet; changing socks often, and using powder in shoes is also good prevention. With patience and perseverance, you may eventually have fungus-free toenails that you will be proud to display at the beach.

References

1. Elewski BE: Once-weekly fluconzaole in the treatment of onychomycosis: introduction. J Am Acad Dermatol 38: S73, 1998.
2. Elewski BE, Hay R: Update on the management of onychomycosis: highlights of the Third Annual International Summit on Cutaneous Antifungal Therapy. Clin Infect Dis 23: 305, 1996.
3. Chiritescu MM, Chiritescu M, Scher R: Newer systemic antifungal drugs for the treatment of onychomycosis. Clin Podiatr Med Surg 13: 741, 1996.
4. McGlamry et al: Nails. Comprehensive Textbook of Foot Surgery 2nd edition: p.277-303; Williams and Wilkins Publishers, Baltimore, MD, 1992.
5. Kligman, AM: Why do nails grow out instead of up? Arch of Dermatology. 84: 313, 1961.
6. Rich P: Nail disorders. Diagnosis and treatment of infectious, inflammatory, and neoplastic nail conditions. Med Clin North Am, 82(5): 1171-83, 1998.
7. Gupta AK, Joseph WS: Ciclopirox 8% nail lacquer in the treatment of onychomycosis of toenails in the United States. JAPMA 90(10): 495-501, 2000.
8. Physicians Desk Reference 2000. 54th edition: 1457-1460, 2020-2021; Medical Economics Co., Montvale, NJ, 2000.

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