What it looks like: Fungal infections of the fingernails usually begin at the side of the nail’s free edge. The fungus typically invades the area between the nail plate and the nail bed, causing the nail plate to separate from the nail bed. Brown, yellow, gray, black, or green by-product of the fungus is often present. Usually only one hand is affected.

Fungal infections are more common on toenails than fingernails, and if you have a fungal infection on your fingernails, you likely have one on your toenails as well. A fungal infection of the nails is often accompanied by a fungal infection of the skin on the same hand that looks like a scaly rash. Only a very small percentage of crumbly or deformed nails are fungal. Orville Stone, M.D., a dermatologist who specializes in disorders of the nails, says that less than one nail per thousand that seems infected actually has a fungus infection. True fungus is not directly caused by acrylic nails.

What you and your nail technician should do: Your nail technician should refer you to a dermatologist, who will diagnose your condition by a wet mount or culture and treat it with an oral medication. It is generally agreed by fingernail experts and scientists that topical medications don’t work in curing fungal infections of the nail.


Mold is part of a large group of fungi that grow on non-living organic matter such as oranges or bread. Molds rarely cause human disease because mold can’t feed on human cells. One type of mold can grow under an injured large toenail that has responded to trauma by forming a thick layer of debris between the nail plate and nail bed. But there is no place for the term “mold” in the discussion of nail disease.


What it looks like: Yeast infections occur where there is chronic exposure to wetness. The posterior nail fold separates and white material oozes out from under the fold. Yeast can result in chronic paronychia. Wearing a bandage can cause a yeast infection.

What you and your nail technician should do: Use Lotrimin cream or Micatin cream, both of which can be purchased over the counter, and avoid moisture. Don’t wear a bandage. The infection will heal in a few weeks.


What it looks like: It leaves a green pocket or stripe down the nail plate. Dr. Stone says that it is not a primary cause of disease; however, it can occur in wet pockets or along with another infection. He does not feel that the pseudomonas organism adds to disease except to cause a green stain. Pseudomonas becomes an infection only in the presence of severe tissue damage such as in burn patients.

What you and your nail technician should do: When the discoloration occurs around the nail, it indicates the area is chronically wet. Don’t bandage it. Dry it out with a hair dryer or use alcohol or diluted bleach (one part commercial clothes bleach to 19 parts water). Polysporin spray also helps. Alcohol and polysporin kill the organism, but the color is a stain that will persist until the nail grows out in three to six months. If there are indications that another infection is present or if the pseudomonas infection is severe, the client should see a doctor. The dermatologist may treat the problem by treating the wet pocket in which the pseudomonas grows. It is okay to cover the discoloration of the nail with polish.

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