Hair Cosmetics

• Products that result in temporary changes to the hair e.g. shampoos, conditioners, hair sprays, temporary colors, etc.
• Products delivering a permanent change to the hair shaft e.g. relaxers, permanent waves, bleaches, permanent colours.

There is, however, a third category which requires closer scrutiny: the process or conditions under which the product(s) is used. It is probable that the vast majority of hair complaints stem from this third group as a result of improper or incorrect use of cosmetic products, either in the home or by professionals.

Wet, virgin hair can be stretched by 30% of their original length without damage; however, irreversible changes occur when hair is stretched between 30% and 70%. Stretching to 80% causes fracture.

Excessive or repeated chemical treatment, grooming habits, and environmental exposure produce changes in hair texture and if extreme can result in hair breakage. These changes can be seen.

microscopically as “weathering” of the hair shaft and contribute to tangling, and frizzing. Weathering is the progressive degeneration from the foot to the tip of the hair. Normal weathering is due to daily grooming practices. Attrition, the main cause of frizz, can be minimized by adequate formulation of cleaning products. On the other hand, if the shampoo formulas do not present the adequate composition, fiber attrition is aggravated.

Although considered as safe products, shampoos can cause contact dermatitis. Common allergens in shampoos are: Cocamidopropyl betaine, methy lchloroisothiazolinone, formaldehyde-releasing preservatives, propylene glycol, Vitamin E (tocopherol), parabens and benzophenones.

Chemical damage by bleaches, dyes, straighteners and even sunlight can weaken hair and increase inter-fiber friction, leading to breakage. An important factor involved in hair breakage is the occurrence of tangles created by combing forces. Where the break occurs along the fiber, correspond to the point of higher combing forces.

Products delivering permanent changes to the hair shaft include permanent waves, relaxers, bleaches and colours. Each of these products causes one or more changes to the fully formed hair that are irreversible and need to be grown out over time.

When patients present it is important for the clinician to appreciate that hair grows at approximately 1 cm per month and, for shoulder length hair, any of the above processes could have been used in the last 12+ months. The patient will not normally proffer this information. This simply means that the effects of the product are still present and may well be the causative factor in the hair problem. This is particularly true of hair breakage and bird’s nest hair (matting). Even when these products are used correctly it is not unusual for the consumer to experience some temporary scalp sensations such as tingling, stinging, and smarting of the eyes. Consumers often believe that no-lye relaxers need less caution compared to lye (caustic soda) relaxers. However, although no-lye products lead to less scalp irritation, both products need to be used with great care. For colorant products, patch testing as recommended in the instructions is essential.

If permanent changes have been undertaken it is important that the individual now understands that the hair is more vulnerable to the everyday practices of washing, combing and drying. The normal weathering process will be greatly increased. Patients should be advised to take extra care and always use hair conditioners liberally.

If left on too long, at too high concentration, or with heat, all of these processes are capable of breaking or completely dissolving the hair fiber. It is also common for salon reagents to be bought in quantity and stored in part used bottles with a large head space. The reagents used in perms and bleaches will self-oxidize and lose efficacy over time making their use in a salon more of an art than a well-controlled science. There is therefore a potential risk in moving to fresh, more active stocks of reagents. Bleaching with hydrogen peroxide is subject to metal catalysis. In rare cases, excessive surface deposits of metals e.g. copper, iron from water supplies may cause rapid hearing with the production of steam or smoke from the client’s hair. Rapid action is essential to minimize damage.

Scarring alopecia rarely results from cosmetic processes and indeed, cosmetic causes of scarring alopecia are poorly documented. They may include traction, localized scalp bums from relaxers, and possibly folliculitis brought on by the use of pomades and heavy oils to protect the scalp during relaxing.

In summary, it is extremely rare for cosmetic products, when used correctly, to cause hair loss. Although contact dermatitis may result in telogen effluvium, the incidence of severe dermatitis from cosmetic products is also very low. Hair loss, including follicular loss and hair breakage, is more likely to result from improper processes, careless use of reagents, or excessive hair care regimes.