Artificial nails can be safe, but you need to be a wise consumer because they can cause problems. Allergic reactions to nail product ingredients, infections, and damage to the natural nail are the most common. According to the Centers for Disease Control and Prevention, to date, there have been no reports of transmission of blood-borne diseases, such as HIV infection (the virus that causes AIDS) or hepatitis, from personal-service workers, who include nail technicians.

Bacterial and fungal infections and skin viruses, such as warts, are the most common nail infections. If bumped or knocked, an artificial nail can separate from the natural nail base, leaving an opening in which dirt and germs can accumulate. If the nail is re-glued without proper cleaning, bacteria or fungi can grow between the nails, spreading into the natural nail.

Furthermore, as the natural nail grows, an opening develops between the natural nail and artificial nail. If this space is not filled in regularly (at least every two weeks) or cleaned, it increases the chances for infection. Fungal infections often occur when an acrylic nail is left on too long (more than three months) and moisture accumulates under the nail.

Nail fungus often causes the end of the nail to separate from the nail bed. Debris may build up under the nail plate and discolor the nail bed. Presently, the best treatments are oral prescription medications - itraconazole (Sporanox), terbinafine (Lamisil), and fluconazole (Diflucan) - or topical treatments - ciclopirox (Penlac Nail Lacquer), the first topical agent approved in the U.S. for this disorder.

Dermatologists, physicians who specialize in the treatment of skin disorders, offer these precautions for artificial nails:

• Test your sensitivity or allergy to artificial nail products by having only one nail done. Wait a few days to see if a reaction develops.
• Avoid applying an artificial nail if the natural nail or skin around it is cut or infected.
• Prevent infection when an artificial nail separates by dipping the fingertip into rubbing alcohol.

Public health experts make these recommendations for selecting a safe nail salon:

• Check that the salon and nail technicians are both licensed. If licenses are not posted, ask to see them.
• Ask how nail implements are sanitized. Heat sterilization is ideal, but most states permit chemical sterilizing, as long as the implements are immersed in the solution for a minimum of 10 minutes between customers. When chemical solutions are used, the product's label should include words like "germicidal" and "fungicidal" to indicate that it can kill germs.
• Wash your hands before nail work begins and insist that the nail technician do the same.
• A new nail file should be used for each customer. The safest thing to do is to bring your own implements.