Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
What causes fungal nails, and what are some of the risk factors?
In normal, healthy people, fungal nails are most commonly caused by fungus that is caught from moist, wet areas. Communal showers, such as those at a gym, or swimming pools are common sources. Athletes have been proven to be more susceptible to the fungus. This is presumed to be due to the wearing of tight-fitting, sweaty shoes associated with repetitive trauma to the toenails. Having athlete's foot makes it more likely that the fungus will infect your toenails.
Elderly people and people with certain underlying disease states are also at higher risk. These include certain autoimmune disorders such as psoriasis and inflammatory bowel disease (Crohn's disease or ulcerative colitis). Also, anything that impairs your immune system can make you prone to getting infected with the fungus. These include conditions such as
AIDS,
diabetes, cancer, or taking any immunosuppressive medications like steroids.
Is nail fungus contagious?
While the fungus must be obtained from someplace, it is not highly contagious. Nail fungus is so common that finding more than one person in a household who has it is hardly more than a coincidence. It can be transmitted from person to person but only with constant intimate contact.
What are the symptoms and signs of fungal
nails?
There are many species of fungi that can affect nails. By far the most common, however, is called
Trichophyton rubrum. This type of fungus has a tendency to infect the skin (known as a dermatophyte) and manifests in the following specific ways.
Starts at the ends of the nails and raises the nail up: This is called "distal subungal onychomycosis." It is the most common type of fungal infection of the nails (90%). It is more common in the toes than the fingers. Risk factors include older age, swimming, athlete's foot, psoriasis, diabetes, family members with the infection, or a suppressed immune system. It usually starts as a discolored area at a corner of the big toe and slowly spreads toward the cuticle. Eventually the toenails will become thickened and flaky. Sometimes, you can also see athlete's foot in between the toes or skin peeling on the sole of the foot.
Starts at the base of the nail and raises the nail up: It is called "proximal subungal onychomycosis." This is the least common type of fungal nail (3%). It is similar to the distal type, but it starts at the cuticle (base of the nail) and slowly spreads toward the nail tip. This type almost always occurs in people with a damaged immune system.
Yeast onychomycosis: This type is caused by a yeast called Candida and not by the
Trichophyton fungus named above. It is more common in fingernails and may be the most common cause of fungal fingernails. Candida can cause yellow, brown, white, or thickened nails. Some people who have this infection also have yeast in their mouth or have a chronic paronychia (see above) that is also infected with yeast.
The term "ringworm" or "ringworms" refers to fungal infections that are on the surface of the skin. A physical examination of the affected skin, evaluation of skin scrapings under the microscope, and culture tests can help doctors make the appropriate distinctions. A proper diagnosis is essential to successful treatment. Among the different types of ringworm are the following: tinea barbae, tinea capitis, tinea corporis, tinea cruris, tinea faciei, tinea manus, tinea pedis, and tinea unguium.
Diabetes mellitus is a chronic condition characterized by high levels of sugar (glucose) in the blood. The two types of diabetes are referred to as type 1 (insulin dependent) and type 2 (non-insulin dependent). Symptoms of diabetes include increased urine output, thirst, hunger, and fatigue. Treatment of diabetes depends on the type.
Athlete's foot (tinea pedis) is a skin infection caused by the ringworm fungus. Symptoms include itching, burning, cracking, peeling, and bleeding feet. Treatment involves keeping the feet dry and clean, wearing shoes that can breathe, and using medicated powders to keep your feet dry.
Neutropenia is a marked decrease in the number of neutrophils, neutrophils being a type of white blood cell (specifically a form of granulocyte) filled with neutrally-staning granules, tiny sacs of enzymes that help the cell to kill and digest microorganisms it has engulfed by phagocytosis.
Diabetes-related foot problems can affect your health with two problems: diabetic neuropathy, where diabetes affects the nerves, and peripheral vascular disease, where diabetes affects the flow of blood. Common foot problems for people with diabetes include athlete's foot, fungal infection of nails, calluses, corns, blisters, bunions, dry skin, foot ulcers, hammertoes, ingrown toenails, and plantar warts.