1 – Nail dystrophy. This is a very common condition that may mimic nail fungus in appearance but is actually caused by trauma. Trauma to the nail may take the form of a traumatic event such as dropping something heavy on the foot or stubbing the toe badly as well as repeated microtraumas such as wearing improper or ill-fitting shoes. It may also be related to certain activities such as running or hiking. The toenail grows from a sliver of issue found where the skin and nail meet just underneath the cuticle. It is not visible to the naked eye. This area is called the nail matrix. The matrix is responsible for new nail cell formation and nail growth. Any incident or activity that may cause increased pressure on this area can damage the nail matrix and thus any new nail that grows may appear thickened, darkened, lumpy or with ridges. While this may appear in any nail, it is very common in the nails of the little toes on both feet, likely related to tight shoes.
2 – Subungual hematoma. Somewhat related to the above condition, a subungual hematoma or “nail bruise” is also the result of trauma. Again, this trauma may be from a single incident or repeated microtraumas over time. A subungual hematoma will form underneath the nail plate as a result of injury or increased pressure to the delicate skin underneath the hard portion of the nail known as the nail bed. This bruising will appear purple, red, black or even green depending on duration and severity. Usually harmless when painless, this condition will grow out over time as the toenail grows out. It will lighten over time and the nail old nail may fall off as a new nail replaces it underneath. In some cases, a severe subungual hematoma may require removal of the nail.
3 – Keratin granulations. Often mistaken for a fungus, keratin granulations appear as white “chalky” spots or streaks on the nail plate. Most commonly seen in women, this is usually noticed when taking nail polish off the nails after having the polish on for several weeks. Excessive wear of the polish as well as the acetone in nail polish remover dehydrates nails causing the formation of white patches of keratin protein in the nail to develop. While this condition is benign and usually treated by rehydrating the nail and taking a break from polish and polish remover, it closely resembles a type of fungal infection called white superficial onychomycosis that requires a different type of treatment to get rid of.
4 – Onychomycosis. Sometimes when something looks like a fungus on the nails, that’s exactly what it is. Onychomycosis is a fungal infection caused by any number of fungal species including yeasts and molds. Depending on the infective organism, the nail may appear white or yellow-brown and may grow looking thickened, darkened and with a crumbly powder substance when cutting. The type of species may be identified with proper lab testing and may better direct medication treatment options.
