Onychomycosis is a contagious, dermatological infection in which the fingernails or toenails are affected by fungi. The condition is common in both men and women of various ages.
Onychomycosis causes changes in the color and shape of the nail plate and, in many cases, leads to nail detachment (onycholysis). Nail fungal infections usually begin with white or yellow spots that appear at the edge of the nail. If left untreated, the infection can spread, often affecting the entire nail. Nevertheless, it can occur in any part of the nail, including the nail matrix, the nail bed, or the nail plate.
In addition to the aesthetic deformation of the nails, onychomycosis may also be accompanied by intense pain or swelling, thus making the patient's daily life more difficult. In more severe cases, it can lead to painful ingrown nails which, when affecting toenails, can significantly impact a person's ability to walk. For this reason, prompt treatment is considered essential.
The causes of onychomycosis vary, and each requires a different approach and treatment. Onychomycosis is caused by three main groups of fungi:
Dermatophytes – responsible for 90% of toenail fungal infections and 50% of fingernail infections. These fungi infect hair, skin, and nails, feeding on the keratin in the nail tissue.
Non-dermatophyte molds
Candidiasis (Candida albicans) – most cases affect the feet, particularly the big toes.
According to Zaias classification, four main types of onychomycosis can be identified during clinical examination:
Distal subungual onychomycosis:
The most common type, which may be primary (affecting a healthy nail) or secondary (affecting already damaged nails, e.g., psoriatic or traumatized nails).
Clinically, nail thickening and brittleness are observed, often accompanied by detachment of the nail from the nail bed (onycholysis), and discoloration ranging from white to brown.Superficial white onychomycosis:
Caused by a fungus that invades the surface of the nail, making it rough, fragile, and presenting with small white patches on the nail plate.Proximal subungual onychomycosis:
A rare form associated with white spots or discoloration (leukonychia) that may spread to the deeper layers of the nail (including the matrix). Usually affects one or two nails and is almost always linked to immunosuppression.Endonyx onychomycosis:
Caused by dermatophytes that also infect the scalp, such as T. soudanense. The infection begins on the nail surface and typically progresses with deep invasion into the nail structure.Total dystrophic onychomycosis:
This is the end-stage of various forms of onychomycosis, involving thickening and discoloration of the entire nail plate and matrix.Candida onychomycosis:
Begins with painful inflammation and swelling of the proximal nail fold, followed by discoloration and eventual nail detachment (onycholysis).Mixed-type onychomycosis:
Clinical features of different types of onychomycosis appear either on the same or on different nails.
Nail Fungus – Treatment
The main goals of antifungal treatment are:
Elimination of the fungal infection
Regrowth of a healthy, normal nail
Treatment options include topical, systemic, or combination therapy, and often require a long duration to be effective.
In all cases, clinical diagnosis must be confirmed by specialized laboratory tests.
Recently, the use of laser therapy is also being studied as a treatment option for onychomycosis.
It is not possible for the patient to determine on their own whether a fungal infection is present in the nails—whether of the hands or feet. Diagnosis is made by a dermatologist following a clinical examination and is confirmed through laboratory testing (direct microscopy of nail scrapings and fungal culture).
It is important to emphasize that no antifungal treatments should be used prior to diagnostic testing, as they may lead to false-negative results.
Proper education and consistent hygiene care of the hands and feet is the best method of preventing such infections.
Here are some useful tips for nail health:
Keep your feet clean and dry, especially after bathing or soaking.
Change socks frequently, especially if they become sweaty.
Always wear flip-flops in pools or locker rooms.
Avoid wearing shoes that are tight, warm, and cause your feet to sweat.
Do not share shoes or towels with others.
Trim and care for your fingernails and toenails regularly and properly.
Disinfect your nail care tools.
Dry your hands thoroughly after exposure to water.
Choose reputable, certified, and clean nail care facilities.
Once a confirmed diagnosis has been made through medical testing and the type of infection has been identified, the treating dermatologist will recommend the appropriate treatment for each case.
The patient must strictly follow the doctor’s instructions, and after completing the treatment course, they should be cautious with their nail care, as recurrence or reinfection of onychomycosis is quite common (with recurrence rates ranging from 10% to 53%).
Additionally, residual nail abnormalities persist in most patients, as onychomycosis is frequently associated with traumatic nail dystrophies.