Nail Fungus Causes and Treatment

Symptoms

A nail fungus manifests as a white to yellow-brown discoloration of the nail, thickening, softening and deformation. The most common form of nail fungus is the so-called distal-lateral subungual onychomycosis, which often occurs on the big toe. In this case, the fungus grows into the nail bed at the outer end and laterally at the nail edges. In a rarer form, only the surface of the nail is infected. Calcareous white material can be scraped off the nail. So-called proximal subungual onychomycosis, which is a fungus in the nail bed at the base of the nail, is common in immunocompromised people. Nail fungus usually starts locally on a toenail. It can spread further and affect the fingernails as well. Nail fungus is primarily a cosmetic and psychosocial problem. It can cause feelings of shame and sufferers fear spreading the fungus further. However, the thickening of the nail can cause the surrounding skin to become inflamed and painful when resting, walking or moving. © Lucille Solomon http://www.lucille-solomon.com

Causes and transmission

It is a fungal infection of the nail apparatus, usually caused by dermatophytes such as or . Nail fungus of the fingernails is more commonly caused by and is less common than nail fungus of the toes, probably due to the faster growth of fingernails. Toe nails grow about 1 mm per month, while fingernails grow two to three times faster. Because the nail must grow out during treatment, a long duration of therapy is therefore required. Nail fungus is contagious. It is transmitted, for example, at school, in the family, during manicures or in swimming pools. In swimming pools, the fungi are very common and are difficult to remove with disinfectants because they are trapped in keratin particles.

Diagnosis

A piece of nail is examined by a physician using a microscope, culture, or other laboratory methods. Drug treatment should not be initiated without diagnosis because it is expensive and laborious, and other diseases show a similar clinical picture. Other conditions such as skin diseases (e.g., nail psoriasis), injuries, and other infectious diseases may be confused with nail fungus.

Nonpharmacologic treatment

Surgical or chemical methods can be used to remove all or part of the nail. Cosmetic covering is also possible. Filing or trimming reduces pressure pain and may improve penetration of externally applied medications. Other advice:

• Nail thickening regularly cut back or file.
• Enlist the help of a podiatrist.
• Let the feet breathe, keep cool and dry, wear air-permeable shoes.
• Shoes should not be tight in the front, otherwise irritation and injury can occur with thickened nails.
• Put on fresh socks made of natural fiber every day.
• Treat the shoes with special agents.

Drug treatment

Medicinal treatment involves the use of drugs that act internally or externally against fungi. A combination of internally and externally applied means is also possible. Nail fungus is persistent, often returns, and treatment takes several months.

Internal treatment

In most cases, internal treatment is more effective than external and more patients can be freed from the fungus. However, more adverse effects are possible and drug-drug interactions of antifungal agents must be considered. Terbinafine (Lamisil, generics) is an active ingredient in the antifungal group that inhibits and kills fungi as they grow. It distributes well in the skin and nails and is used in tablet form to treat nail fungus. The treatment period is 6 weeks for fingernails and 3 months for toenails. Terbinafine is considered the most effective agent against nail fungus. However, disadvantages include possible systemic adverse effects. The most common side effects include digestive problems, skin rash, joint and muscle pain, headache, taste and smell disorders. see under Terbinafine for nail fungus Itraconazole is an alternative to terbinafine, especially for yeast or mold infections, and is approved in many countries for this indication. It is slightly less effective than terbinafine and is administered as continuous therapy or as pulse therapy.Other oral antifungals are used less frequently. Fluconazole is less effective than itraconazole and is not approved for this indication in many countries. Griseofulvin is no longer commercially available in many countries.

External treatment

External treatment is generally less effective than internal treatment. A longer treatment period is needed, and not all patients can be cleared of the fungus. It is a supplement or an alternative, for example, in cases of mild to moderate and especially superficial infestation and at the beginning of the disease. A clear advantage is the very significantly lower risk of adverse effects. Antifungals:

• Amorolfine (Curanel, Loceryl). Use: degrease nail 1-2 times per week and apply varnish. Longer-term therapy, 4 to 6 months to 1 year. see under Amorolfin against nail fungus.

• Ciclopirox (Ciclopoli nail polish, 8%) see under Ciclopirox against nail fungus.

• Miconazole was commercially available as a tincture (Daktarin). The tincture is no longer sold see under miconazole against nail fungus.

• Efinaconazole (Jublia, USA) is applied in the form of a solution once daily for 48 weeks.

• Bifonazole is commercially available in Germany in combination with the keratolytic urea. In many countries, this combination is not available, but can be imported. see under bifonazole urea ointment for nail fungus.

• Terbinafine could in principle also be applied topically, but is not approved for this indication in many countries and no varnish is commercially available.

• Tavaborol inhibits the protein synthesis of fungi.

Keratolytics:

• Urea in the form of urea ointment 40% to dissolve the affected nails. The urea is applied only to the affected areas of the nail, which can be removed over time see under urea ointment.
• The potassium iodide ointment 50% is mentioned in the literature, but is less common today.

Nail fungus pens:

• There are several nail fungus pens available in stores, which are approved as medical devices. They contain acids and essential oils. Acids such as acetic acid or lactic acid lead to an acidic environment in the nail and should thus inhibit the growth of the fungus.

Disinfectants:

• Povidone–iodine is fungicidal and is commercially available as a tincture that can be applied with a brush. We have no data on its efficacy. It is approved for cutaneous fungus but not explicitly for nail fungus.

Other methods:

• Nail fungus, as already mentioned, is often difficult to treat and stubborn. Therefore, patients also try various substances that are effective against fungi. These include, for example, tea tree oil, Dakin solution (sodium hypochlorite), Vicks Vaporub ointment, propolis or hydrogen peroxide. It is important in such a trial that the agents are locally tolerated and do not cause adverse effects. Clinical studies are available in part.