Those annoying and esthetically troubling white spots, and worse, patches, have become more prevalent since UV gels (also called LED gels and soak-off gels), hybrids and longwearing nail polishes became popular. Nail professionals blame the product, and manufacturers blame the nail professionals. Both blame their clients. It has become a blame game.
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Those annoying and esthetically troubling white spots, and worse, patches, have become more prevalent since UV gels (also called LED gels and soak-off gels), hybrids and longwearing nail polishes became popular. Nail professionals blame the product, and manufacturers blame the nail professionals. Both blame their clients. It has become a blame game.
What are they? These are not fungal infections. But, they manifest themselves as a similar yet different nail discoloration, and diagnosing them is outside of a nail professional’s scope of practice. Nail professionals refer to the white patches as dehydration, while the scientific experts in the field call them nail damage. Granulation is the term used by medical professionals. Because of these various terminologies, the real cause of these white areas is a controversial issue in the nail industry.
With the naked eye, one can see the white spots consist of tiny holes resembling divots made by golfers on a well-manicured fairway. In Nail Structure and Product Chemistry by Douglas D. Schoon, images obtained under high magnification using scanning electron microscopy showed clearly that the smoothness of the nail surface is disrupted in the area occupied by the white spots.
The manifestation of white spots is due to the disruption in the way light travels. When a ray of light hits a smooth, glossy surface, the light is reflected at a defined angle, and we see a uniform light intensity and coloration upon viewing this “specular” reflected light. When light hits an irregularly shaped and roughened (textured) surface, the light rays are scattered in many directions because the surface is not uniform, and our eyes perceive this diffused light scattering as white spots.
Causes of Nail Damage
These visual observations represent evidence that white spots are a manifestation of nail damage. But, what are the possible causes of nail damage? In general, the root cause may be physical trauma, chemically induced damage or a combination of these two.
Physical trauma is when you hit, scrape or physically gouge the nail plate. Chemically induced trauma is when you leave an aggressive chemical such as caustic cuticle softener too long on the nail plate. When you use a metal instrument to scrape a nail wet with the softener to push the cuticle back, this becomes a combination of chemical and physical trauma.
There are misconceptions that products alone cause peeling or delamination damage to nails. Brands blame the nail professionals for improper removal of gels and acrylics, while nail professionals blame consumers for forcefully removing these coatings. Both can cause nail damage. I believe that reputable brands develop nail products that are safe and effective when used properly. Gels and polishes are coatings that alone will not damage the nails, but their strong interaction with the nail plate can cause damage.
A depiction of how we perceive light.
Absorption
All coatings, including nail polishes, when applied to a solid surface, will result in shrinkage of the coating. Solvent-based polishes will shrink because there is a loss of mass when the solvents evaporate. Gel polishes shrink because they contain solvents and then shrink further during UV or LED exposure; their curing densifies the coating as the molecules move closer together when the monomers react to form a crosslinked polymer. The shrinkage of the polish coating attached to the nail plate results in a film with residual stress and is in tension. Too much stress will lead to film cracking, peeling off, buckling or the layers delaminating, depending on the weakest link in the system.
We may consider the dried nail polish and the nail plate as a multilayer composite consisting of the nail polish layers and the keratin layers comprising the nail plate. The nail polish layers (base coat, layers of color and top coat) normally cannot be peeled away from each other because they are designed to interpenetrate each other, and therefore, dry into one film. The nail plate, on the other hand, consists of layers of interdigitated keratin fibers.
While human nails are the same on the macro scale, they are different on a granular level. For instance, we consider healthy nails to be those that are tough, grow beyond the nail bed without splitting and have a uniformly smooth surface. The interdigitated keratin layers of healthy nails will have strong adhesion between them. Conversely, weak nails will have weak adhesion between the keratin layers.
During its application, the polish fills the spaces on the nail surface first, and then it decreases in thickness as more solvent evaporates. The polish’s movement in the planar direction is constrained by its adhesion to the nail, leading to the residual stress in the dried polish film.
We know that nails absorb water during our normal daily activities, such as when we wash our hands, wash dishes or take a shower or bath. As a result, they change in dimension by expanding when wet, and then retracting when dry. However, the dry polish does not absorb water and therefore does not expand or contract with the nail, and this mismatch in their hydration expansion coefficients increases the residual stress present in the polish-nail multilayer composite system.
A multilayer composite will fail at the point of least resistance or the weakest link in the system. When the polish is brittle and its adhesion to the nail is weak, the polish will crack and chip. When the polish is mechanically strong and its adhesion to the nail is weak, it will pop or peel off in one piece. But, when the polish has strong mechanical and adhesive properties to the nail, it can cause the nail keratin layers to delaminate. The structure of the keratin layers and their interlamellar adhesion may not be completely uniform across the nail surface. Chunks of keratin at the areas that are weakly linked to each other are pulled away by the polish, causing the divots on the nail surface. When this interlamellar adhesion is uniformly distributed across the nail surface, delamination of the nail could occur along the free edge.
White Spot Prevention
Why do the white spots appear only with longwearing polishes? It stands to reason that the longwearing polishes have stronger adhesion to the nail than their traditional counterpart. Traditional polishes have weaker adhesion and release their hold on the nail when the nails absorb water and expand.
How do we prevent these dreaded white spots? Presently, the solution is to keep the polish more flexible and the nails protected from water. It is wise to apply a penetrating oil daily and as often as possible. The oil acts as a plasticizer for the polish by increasing the mobility of the polymer chains, thereby decreasing the residual stress in the coating. The oil coats the exposed nail areas, minimizing the absorption of water and the resulting expansion by the nail.
While white spots cannot yet be 100% eliminated, the professionals’ best weapons in prevention are inquisitive education and proper use of high-quality products. Do not be afraid to ask the tough questions. Responsible manufacturers are both scientifically knowledgeable and dedicated to your success.
About the Author
Vivian Valenty, Ph.D., is the founder and president of VB Cosmetics, the creator and manufacturer of Dazzle Dry. She is also a member of Nailpro’s 2022 advisory board. She obtained her doctorate in chemistry from Penn State University, and for the past 33 years, has been creating products for the professional nail industry.
