Prevention of allergic contact dermatitis from nail varnishes and hardeners

Safety and Efficacy of Nail Products

Over the past several decades, the commercialization of nail cosmetics has increased. From nail polishes to artificial nails, different methods of nail beautification have become popularized. However, the impact of these products remains largely unknown. Governments have passed legislation in attempts to regulate nail cosmetics, but these regulations may not be adequate and are difficult to enforce. Knowledge of the safety and efficacy of nail products remains limited due to the relative dearth of literature published on the topic. This review serves to summarize and interpret the data available regarding common nail products and their safety and efficacy. Nail products such as nail polish, nail polish removers, and artificial nails have shown to have some adverse effects through case reports and studies. Harmful substances such as toluenesulfonamide-formaldehyde resin and methacrylates have been identified in commercial nail products, leading to several adverse effects, but in particular, allergic contact dermatitis. Exposure to substances such as acetonitrile found in removers may have more toxic and caustic effects, especially if ingested. In addition, for nail technicians there are negative effects linked with occupational exposure. Compounds used in nail products may become aerosolized and lead to asthma, eye and throat irritation, and even neurocognitive changes.

Nail cosmetics in nail disorders

The clinical features of nail dystrophies depend on the part of the nail that has been damaged. Due to the important functions of fingernails and toenails, any abnormality of the nail causes impaired function of the hand or foot. Moreover, the aesthetic aspect of the nail may affect employability, self-esteem, and interaction with other people. Because the nails are often difficult to treat, cosmetology may be an effective support to medical treatment. Nail cosmetics may help the patient to cope with his or her nail dystrophy while waiting for treatment to show its efficacy. It may also be the only choice to hide nail dystrophy where the nail is irreversibly damaged. Nail cosmetics may also function at treatment for onychtillomania, nail biting, and nail ingrowing.

Allergenic ingredients in nail polishes

It has been known since the 1940s that nail polishes contain allergenic ingredients. The aim of this study was to clarify whether the nail polishes on the market today contain significant amounts of allergens, and what the solvents are. The following ingredients were determined: toluene, toluene sulfonamide formaldehyde resins, free formaldehyde, acrylates, methacrylates and certain organic solvents. The study comprised 20 brands and 42 samples. All the nail polishes analysed contained allergenic toluene sulfonamide formaldehyde resins (TSFR), in concentrations from 0.08 to 11.0%. The concentration of total formaldehyde varied from 0.02% to 0.5%. The more TSFR a nail polish contained, the higher was its formaldehyde content. Probably not only TSFR-allergic but also formaldehyde-allergic persons may get dermatitis from many of the nail polishes studied. The concentrations of acrylates and methacrylates were so small that they are of practical significance only to those previously sensitized to acrylates. Of the organic solvents, toluene was still widely used, whereas xylene was found in only 1 product. The nail polishes on the market today are not safe for all consumers. However, according to the regulations of the European Union, the packaging labeling of all cosmetic products must be supplied with a list of ingredients from the beginning of 1998. This will help the consumer to avoid allergenic products. A better alternative could, however, be to substitute the most allergenic ingredients with substances possessing minor allergy potency.