Allergies to Cosmetic Ingredients

Most individuals can use cosmetic products without difficulty. However, despite intensive

efforts to formulate hypoallergenic products, there is a small percentage of people suffering from skin

irritations and allergic contact dermatitis with cosmetic use. The overall frequency of dermatitis

produced by cosmetics is difficult to determine. If the consumer experiences a reaction that is mild

and transient, he/she will not usually seek medical attention, but simply stop using the suspected

product. In addition to eczema, there is sometimes burning, stinging, or itching without visible skin

lesions.

Major Allergens

There are 3 categories of cosmetic ingredients that induce allergies more often than others:

• Fragrances

• Preservatives

• Hair colorants & agents for permanent waves

Fragrances are the most frequent allergens, but specific allergen avoidance is complicated by the

fact that manufacturers are not required to disclose the exact fragrance ingredients in products.

Also, when a product lists essential oils, patients may not recognize this as fragrance.

Another important cause of contact dermatitis caused by cosmetics is the variety of preservatives

added to the cosmetic products to maintain freshness. There are a number of preservatives

used in cosmetics that can cause eczema in the sensitive consumer. For example, formaldehyde

releasers are very frequent allergens.

Other important causes of contact allergy include the active agents in hair- and nail-care products

such as those for permanent hair waves, permanent hair coloring, artificial nails, and nail polishes.

Fragrances

Fragrance is the most common cause of contact allergy caused by cosmetics according to the North
American Contact Dermatitis Group (NACDG) 1998–2000 patch-test results. Fragrances can be
naturally derived from plants or synthesized in laboratories. Although >5000 different fragrance
chemicals are known, it is possible to identify up to 95% of fragrance allergic patients by testing the
following 11 substances: cinnamic aldehyde, cinnamic alcohol, geraniol, eugenol, isoeugenol,
oak moss absolute, alpha-amyl cinnamic alcohol, sandalwood oil, hydroxycitronellal, narcissus
absolute, and ylang-ylang oil. After a fragrance allergy is once established, the
patient should avoid indefinitely all products that contain fragrances. If somebody is sensitive to
only a single or a few fragrances, avoidance of those particular fragrances may allow the
successful use of others. But again, because of the fact that fragrances are not required for
package labeling, it is essentially impossible to knowledgeably avoid a particular fragrance.


Allergens in Hair Care Products

The active agents in hair care products, including hair colorants and permanent waves, are the third
most common source of allergic reactions to cosmetic products. One of the most common allergen is
paraphenylenediamine (PPD), a chemical used for permanent hair colorants. Up to 5% of all women
show allergic reactions to PPD. Once the hair colorant is fully developed, PPD is no longer an
allergen. Patients sensitive to PPD will recover from their allergies once PPD is oxidized and do not need
to cut their hair. The agents used in permanent waves are also an important cause of dermatitis.
Glyceryl thioglycolate is found in acid (heat) permanent waves used exclusively by salons and
can cause allergies in 2.0% of test persons. Ammonium thioglycolate is the chemical in alkaline
permanent wave products intended for home use and can also cause dermatitis. Patients who react to
glyceryl thioglycolate permanent solutions can typically tolerate ammonium thioglycolate-based
perms and vice versa.


How to Test

A widely used allergen patch skin test with a series of allergens is the TRUE Test®. It is
applied on the back and then the results (local skin reactions to the allergens) are read after
48h. The test includes the 23 most common allergens as: nickel sulfate, wool alcohols,
neomycin sulfate, potassium dichromate, caine mix, fragrance mix, colophony, paraben mix,
balsam of Peru, ethyl-enediamine dihydrochloride, cobalt dichloride, p-tertbutylphenol
formaldehyde resin, epoxy resin, carba mix, black rubber mix, Cl+Me-Isothiazolinone,
quaternium-15, mercaptobenzothiazole, p-phenylenediamine, formaldehyde,
mercapto mix, thimerosal, and thiuram mix.