When Chris Martin, the lead singer of Coldplay, is belting out “and they were all yellow” he is not referring to yellow nails. One of the less sexy nail topics — albeit an important one — yellow nails are a common issue seen in both medical practices and nail salons. There are several causes of yellow nails, some cosmetic in origin and others indicative of an underlying medical issue, so it is important to understand when to refer your client to a physician.
One of the most common causes of yellow nails is secondary staining from nail lacquer. Because the porosity of the nail varies from person to person, certain individuals who inherently have more porous nails are more prone to pigment migration and thus secondary yellowing. Another common cause of polish-induced nail yellowing is polish remover. Polish remover dissolves polish, resulting in the migration of pigments that then can leach into the nail plate causing yellow discoloration. Theoretically, the longer the soak, the more leaching that can potentially occur. The last factor related to polish has to do with the dye content of the polish. Not all polish dyes are alike. Generally, the darker the color, the more the pigment has an opportunity to migrate and leach into the nail plate to cause yellowing. While darker colors tend to be the culprit more often, this phenomenon can also occur with lighter colors as well. Yellowing from polish is not a brand-related phenomenon. Yellowing is an issue that can occur with all brands.
How do we distinguish polish-induced yellowing from other causes of nail yellowing? When polish is the sole cause, the nail will be healthy looking and intact, but have a yellow hue throughout. The surface will be smooth and a normal thickness, as opposed to fungal nails where there is thickening or subungual (under the nail) crumbling. And importantly, there will be a history of prior polish application.
Since this is a cosmetic issue, I always tell patients that they have two choices when it comes to treatment. They can take a nail polish holiday and take action to try to lighten the nail or they can cover it with polish. Those interested in treatment have a few options. If the stains are severe, they can be lightened by using a dilution of hydrogen peroxide (H202). Combine three to four tablespoons of H202 and 1/2 cup of water and mix well, then soak nails for two minutes. Using a soft toothbrush, gently scrub the surface of the nails. Rinse with water. Repeat two to three times per week as needed. Alternatively, you can use a whitening toothpaste as these are formulated with hydrogen peroxide. A third option is the Dr. DANA Nail Renewal System. Step 01 contains glycolic acid and combined with our Step 02 Perfect Grit Priming Wand, the system is very effective at removing nail discoloration. Avoiding polish is essential during the treatment period.
To prevent staining from occurring in the first place, it’s imperative to keep the nail surface healthy. Over-filing can theoretically lead to increase pigment leaching into the nail. Don’t forget to use a good base coat unless the product specifies that one is not needed. In most instances, a good quality base coat will create a protective barrier layer for the nail plate. Lastly, try to remove polish quickly. If you need to rub for 10 minutes, then the pigments have a better opportunity to leach into the nail. Quickly remove the polish and wash hands immediately.
Other non-medical causes of nail yellowing include staining from exposure to ingredients such as tobacco, tanning products, or henna. In these cases, a thorough exposure history will usually uncover the yellowing culprit.
When It’s More Than Cosmetic
There are several causes of nail yellowing that are due to medical conditions, the most common being fungal infections of the nail. Fungal infections can make the nails thick, yellow, and crumbly. Proper diagnosis and treatment are essential to successful treatment. Nail fungus (onychomycosis) affects approximately 35 million people in the United States. You are bound to see this commonly in the salon and it is vital to recognize, as it can be contagious. As stated, fungal nails can be yellow, thick, and crumbly or they can have yellow streaks within the nail plate and be generally smooth and intact. It is far less likely to have a true fungal infection of the fingernails (i.e., one that is caused by a dermatophyte).
Most toenail fungus starts off in the soft tissue, as athlete’s foot, then enters the nail when there is an injury or lifting of the nail. If you suspect that your client has a toenail fungus, you should refer her to a dermatologist or podiatrist for treatment and exercise the usual standard precautions during the client’s visit.
Onycholysis, or separation of the nail plate from the underlying nail bed, is another potential cause of nail yellowing. This common condition is often observed on the fingernails, in contrast to onychomycosis, where the majority of cases are confined to the toenails. When the nail lifts off of the nail bed, it will appear as a white-to-yellow opacity in the area of separation. This is due to air and other debris under the compromised nail plate. Although there are many causes, the most common include overly aggressive cleaning under the nail as well as some inflammatory conditions such as psoriasis. When the nail is separated, yeast often colonize on the nail bed because the barrier has been compromised, allowing water and moisture to settle under the nail — the ideal conditions that allow yeast to flourish. When you see onycholysis, your client should be referred to a dermatologist for treatment. I usually have my patients adhere to a strict irritant avoidance regimen where they avoid nail polish remover and exposure to household chemicals and water. Polish removers are strong solvents that will cause irritation to the delicate nail bed tissue when there is an opening under the nail plate. Additionally, a prescription topical anti-yeast treatment is prescribed.
Yellow nail syndrome is another non-cosmetic cause of nail yellowing. The toenails appear thick and have a yellow-to-green tinge and frequently lack a cuticle as well as lunula (the half moon that is usually visible on the thumb nail and great toenail). This is due to failure of the nail to grow sufficiently and is associated with lymphatic disease, as well as lung disease or malignancy. The underlying disorder must be treated, but tends to be chronic.
Dermatologists treat skin, hair, and nails. I am a board-certified dermatologist and I specialize in the treatment of nail disorders including inflammatory diseases of the nail, cosmetic issues related to the nail, cancers of the nail, sports-related nail injuries, and nail infections.