What is Onychomycosis?

This is a fungal infection that is most often present in your toenails but can also appear in your fingernails. The reason that you see it most often in toenails is because this fungus that causes onychomycosis thrives in environments that are damp and dark. It is also referred to as nail ringworm. It is very common for a person to have some type of fungal infection and affects millions of people worldwide. In the United States approximately twelve to fifteen percent have a toenail fungus infection. Adults are thirty times more likely to have this type of fungal infection than children. In children under the age of eighteen only two point six percent have onychomycosis but ninety percent of senior citizens have it.There are several subtypes of onychomycosis that are based on the progress and cause for the infection and are:

  • White superficial onychomycosis (WSO) - this is a rare form of onychomycosis and usually only affects your toenails.
  • Distal lateral subungual (DLSO or DSO) which means the area that is under your nails. This is the type that most people have.
  • Proximal subungual onychomycosis (PSO) - this is the one that is the least common
  • Endonyx onychomycosis (EO)

A person who has onychomycosis can have a combination of any of these subtypes.

Onychomycosis Symptoms

When a person starts with onychomycosis it will normally start at the far end of the nail that if not treated will grow inward. On your nails it grows on your nail bed and feeds on the protein, also known as keratin, which makes the upper part of your nail. The nail can also change varies colors from brown, dull yellow and even black sometimes. If you have onychomycosis on your toe nails the two that are most susceptible are your little and big toe. There are also times where the nails, especially on the toes, become so hard that it is hard to cut them. If it is a severe case you could even lose the nail. You may also notice a foul smell coming from underneath the infected nail and the nail can also swell due to the keratinous debris under the nail.White superficial onychomycosis (WSO)

  • On the surface of your nail plate you will see either patches that are powdery-looking or have small white speckles
  • Your nail will become rough
  • It will crumble easily

Distal lateral subungual (DLSO or DSO)

  • Your nail plate will be thick and will appear opaque or cloudy
  • Your nail bed under the nail will harden and become thicker
  • Your nail will separate from the nail bed underneath it
  • Your nail may appear to be discolored and range from white to brown
  • Edge of your nail will become severely eroded.

Proximal subungual onychomycosis (PSO)

  • Near your nail bed you will see discoloration or white spotting streaking start to develop and could extend to deeper layers of your nail
  • Near your cuticle your nail plate becomes white but at the end it is normal looking

Endonyx onychomycosis (EO)

  • Your nail plate will have a discoloration that appears milky white
  • It will not separate from the nail bed
  • The area that is under your nail will not harden or become thicker

Having any type of onychomycosis on your toe nails could disturb your daily activities because you may have trouble wearing your shoes and even with walking.


The cause of onychomycosis will usually depend on the subtype that you have.

  • White superficial onychomycosis (WSO) - this is caused when the fungi directly invades the surface of your nail plate and then infects your nail bed secondarily.
  • Distal lateral subungual (DLSO or DSO) - this type is caused when the fungus spreads from your skin and invades the underside of your nail where it meets your nail bed.
  • Proximal subungual onychomycosis (PSO) - this subtype is caused when the fungus invades the skin around your nail (cuticle), your nail fold, and then penetrates your nail plate.
  • Endonyx onychomycosis (EO) - this cause is when the fungi reaches your nail from the skin and invades your nail plate.

In addition to the various causes for the subtypes there are also general causes. As mentioned onychomycosis is caused by a fungus and in the human environment there are many different fungi that can cause this medical condition. There is one special fungi called dermatophytes and what encourages them to grow is a wet, warm environment. For example, if you are a person who wears heavy shoes and constantly have sweaty feet this type of environment will encourage this special fungi to grow and possibly result in them having onychomycosis.Other causes might include:

  • Poor hygiene of the nails on your feet and hands
  • Wearing tight-fitting shoes for a long period of time
  • Having an abnormal level of pH of your skin
  • Having contact with someone who is infected with dermatophytes


There are also things that you can do to help prevent getting onychomycosis, especially of the feet. Prevention can include:

  • You should make sure that you are wearing clean socks every day. If you are one whose feet sweat a lot you should wear cotton socks.
  • Try to wear shoes that let your feet breathe
  • When going to swimming pools and public gyms wear flip flops or some type of shoes so you do not get infected from the dermatophytes on the floor
  • You should also keep your nails clean and dry, both fingernails and toenails.

If you have onychomycosis treating it can be challenging. Most over-the-counter anti-fungal ointments so it is important that you not delay seeing your physician or podiatrist, especially if you are a diabetic. It usually involves you taking a prescription oral antifungal medication. Depending on how severe your case of onychomycosis is you may have to take it for six to twelve weeks. There may still be cloudy, yellowed, or crumbling nails until a new nail has fully grown back in. You should also trim your nails short so you see less discoloration.

Is onychomycosis contagious?

Yes it is a contagious medical condition and can be transmitted to other parts of your body and from one infected nail to another nail, whether it is your fingernails or toenails.

Onychomycosis Pictures

May 13, 2014
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