According to the U.S National Library of Medicine, 50% of all nail diseases is caused by fungus. Nail fungus affects both the fingernails and toenails and ranges in severity. Once affected, the nail develops a yellowish or brownish patch, and in some cases, it may have a foul smell. In severe situations, the nail may separate from the nail bed and become very thick. Usually, nail fungus begins after the surrounding skin suffers a fungal infection, and the nail acts as a reservoir for reinfection once the skin is treated. Common types of nail fungus infections include;
Distal subungual onychomycosis
The same fungi are responsible for athlete’s foot cause this nail infection. It attacks the skin of the nail bed and the nail itself. The infection starts at the end of the nail bed, turning the nail yellow. With time, pieces of skin and nail debris build-up under the nail and as the condition worsens. The nail may crumble and split, or even break away from the skin. Nail fungus as a result of distal subungual onychomycosis can be difficult to treat, making it a lifelong condition. This infection affects the toenails and is mostly caused by ill-fitting shoes or made worse by the same.
Although uncommon, this infection can affect the nail and the skin around it. As the name suggests, it is caused by a yeast infection. It affects both toenails and fingernails but more common on the fingers. The fungus attacks the weakened areas of the nail causing discoloration and then distorts the shape of the nail.
The nail may sometimes look thicker than normal, and there may be additional signs of infection such as tenderness and swollenness in the skin on the nail fold. Unlike other nail fungal infections, this may be painful. The culprit behind the infection is common yeast, and thus poses a risk to those that sweat a lot of the palms and feet or those who spend a lot of time in the water.
Proximal subungual onychomycosis
This is more common in patients with HIV. It infects the base of the nail, causing the skin to thicken and eventually separate from the nail. The base of the nail, known as the lunula, will often appear white and the nail will be opaque. This means that any new nail growth is attacked immediately it begins to show, often because the immune system is not functioning properly. Unless the underlying condition is controlled, nail infection caused by proximal subungual onychomycosis will often recur.
White superficial onychomycosis
This is a common type of nail fungal infection that is easily treated. It affects the top surface of the nail, forming white spots. When untreated, the entire nail surface will be covered with the white crumbly powder. The structure and shape of the nail will not be affected, and therefore it is less likely that the condition will become debilitating or painful. This is a less serious nail fungus infection compared to the rest, and you may hardly come across it as it heals fast and easily.