Lab Reports

Q: I have a client who has developed a raised area 1ike a mountain ridge down the center of his nail. It goes all the way from the bottom of the nail to the tip. What is this?

Dr. MacDougall: A ridge down the middle of the nail as you are describing is referred to as a pterygium. This occurs when the nail matrix is destroyed. As a result, a portion of the nail plate is lost, and this is then often accompanied by an overgrowth of tissue from the proximal nail fold which results in the pterygium.

A number of things can destroy or damage the nail matrix, including certain genetic disorders, medical diseases such as lichen planus and Raynaud’s syndrome, and physical trauma to the nail. With a single nail involved, the most likely trigger would be trauma. Unfortunately, once the matrix is damaged severely enough, there is no way to reverse it and create a normal nail.

Q. Can you explain how the nail remains attached to the nail bed while still growing forward? Does the nail bed “grow” too?

Dr. Mix: The nail plate is attached to the nail bed by a tissue called the bed epithelium. The bed epithelium arises from the distal matrix bed. (The distal matrix bed can be seen as the lunula through the nail plate.) The bed epithelium adheres tightly to the nail plate and is loosely attached to the nail bed. This allows the bed epithelium to slide over the nail bed as the nails grow. As the nail grows over the end of the finger or toe to become a free edge, the bed epithelium meets the skin and builds up as a cuticle-like structure called the sole horn. The sole horn can be visualized as a grayish band, called the onychodermal band, immediately before the free edge of the nail. (To see this band, apply light pressure to the nail plate.) This is confusing, but if you think of the lunula as being the visible part of the matrix bed, and then think of the onychodermal band as being the visible portion of the sole horn, it becomes easier to understand.

Besides acting as the attachment of the nail plate to the nail bed, the bed epithelium also keeps the nail plate growing in the proper direction as it slides over the nail bed. The bottom of the bed epithelium has microscopic ridges and grooves which track in corresponding ridges and grooves on the top of the nail bed. This tracking mechanism keeps the nail growing straight.

Q. Is there any type/brand of nail polish that would be recommended for people with extreme sensitivities to odors, such as people with allergies or asthma?

Sunil Sirdesai: In order for nail polishes to dry quickly, it is necessary, using today’s technology, to use only low-boiling-point (highly volatile) solvents to carry film-forming resin (i.e., nitrocellulose or cellulose acetate butyrate, polyvinyl butyral, etc.).

These low-boiling-point solvents are responsible for the odors. Efforts are underway to introduce water-based nail polishes that have characteristics and working properties similar to the existing organic-based polishes. These polishes, when introduced, may solve the problem for people with extreme sensitivities to odor.

Doug Schoon: Technically, it is impossible to become allergic to an odor. It’s actually certain vapors that can cause allergies and/or aggravate existing cases of asthma. (Vapors from odorless products can just as easily cause respiratory problems, so it is unwise to judge any product by the way it smells.)

People with respiratory sensitivities should be especially careful to use proper and adequate ventilation with any product that evaporates or creates vapors (i.e., nail polish and remover). All nail polishes should be used with proper ventilation and none are safe if this common sense safety rule is ignored or the products are used incorrectly.

Q. Can acrylics or other nail products cause eczema? One of my clients is being treated without much success, and I just wonder if the UV acrylic or another product I am using might be causing the problem.

Schoon: Many types of cosmetics, including nail products, can cause eczema. UV acrylics and gels, liquid monomers, and wrap resins are all potential irritants and all skin contact should be avoided.

Adverse skin reactions to enhancement products usually occur after four to six months of prolonged and/or repeated skin contact. These adverse reactions are usually found where the bare skin is repeatedly touched with the product. The most likely parts of the skin to be affected are the cuticles, sidewalk, fingertips or pads, backs of the hands, wrists, and face.

Luckily, these problems are easy to prevent if the proper care is taken. All skin contact with adhesive, gels, monomers, and filings should be avoided. Change UV lamps three times per year, avoid applying UV curing product too thickly, never brush or clean the skin with liquid monomer, avoid using wet beads, and keep filings off the table, face, and hands.

Preventing adverse skin reactions is easy if you are careful and knowledgeable. It is the responsibility of all nail professionals to understand health concerns related to salon work.

Editors note: For more information on avoiding allergies and other adverse skin reactions, you may want to read Doug Schoon’s book Nail Structure and Product Chemistry from Milady Publishing, (800) 836-5239.

Q. Awhile back I had to remove my client’s artificial nails with pure acetone and replace a full set of acrylic nails. Suddenly she developed some kind of an allergic reaction. Her cuticles got very itchy, swelled up, and eventually got very dry, and her skin peeled. Ever since then she seems to get that way every time I refill her nails. This lasts for a couple of days. I can’t figure out why all of a sudden she is suffering like this.

MacDougall: What you are describing sounds like some type of contact dermatitis, which can appear quite suddenly. If it only lasts for a couple of days, then it may not be allergic contact dermatitis (such as a poison ivy reaction which may last several weeks), but an irritant contact dermatitis (such as what would happen if you kept rubbing laundry detergent into your skin), which may only last for a few days.

I would suggest you tell her to stop all nail services and use gloves for dishwashing and laundry for several weeks to give the tissues a chance to completely heal. Then, as an extra precaution, apply a film of Vaseline to the entire cuticle to protect it prior to applying any materials to the nail. Even with the Vaseline layer, be very careful not to get any materials on the cuticle.

If the problem persists, then refer her to a dermatologist. She may need to be patch tested for allergic contact dermatitis.

Q. I have heard that you should only apply a quick-dry top coat over wet polish — that if you apply it-over dry polish it will peel off. Is this true?

Sirdesai: I don’t think it makes a difference whether you apply quick-dry top coat over wet polish or dry polish. Any coat will peel off if you apply it over a non-compatible surface. In some cases, the surface of dried nail polish is a compatible surface for a quick-dry top coat.

Unless there are traces of oil on the nails, there should be no reason for the top coat to peel off. What distinguishes quick-drying top coat from regular top coat is that the quick-drying top coat has a higher ratio of volatile solvents than the regular top coat.