Allergy to cosmetics, intolerant skin and hypoallergenic creams

1. Is there an allergy to cosmetics?

The "allergy" to cosmetics exists. I put “allergy” in quotes because it is a general definition, which we dermatologists refer to as contact dermatitis or eczema. the Contact dermatitis occurs when a substance "in contact" with the skin inflames it. This inflammation can occur in two ways, one by contact in excess of an irritating substance, later we call it "irritant" (such as: bleach, usual hand washing, cold, excessive heat, etc.) or because the patient has a proper reaction to the agent that comes into contact with the skin, in this circumstance an allergy itself. The difference is that any irritant in sufficient quantity can irritate any skin, however, in allergic contact dermatitis the patient "defines" his own immune reaction.

Once located, contact dermatitis to cosmetics represents approximately 2 to 4% of visits to the dermatologist, it is more common in women and in the The 60% of the cases are truly "allergic" (and non-irritating) (1). The estimated prevalence in the general population is lower, calculating around 0.01 to 0.03% of the population with allergy to cosmetics. This prevalence is estimated, since it is estimated that only 15 to 30% of the patients go to the dermatologist (2), and that the majority avoid the “suspicious” product without going to the doctor.

Therefore, it is a reason for consultation that exists, is unusual and has an impact on the quality of life of patients (1,2).

2. What happens to my skin if I am allergic to creams?

What arises is the appearance of eczema (dermatitis), a irritation of the skin in the product contact area. Eczema can manifest acutely, with exudation and vesicles or chronically, with peeling and redness of the skin. Allergic eczema, once triggered, can become generalized and affect distant areas from where it originated, in the form of papules, vesicles and dermatitis in other locations.

3. What cosmetics can cause allergies?

Any product on the skin is capable of producing allergies. The most frequent are moisturizers and gels or soaps to clean the skin. Then we also find the tints and hairdressing products and other cosmetics such as nail polish or sunscreen (1).

Most cream allergies occur on the face (20%) and hands (20%), with generalized or leg forms less common. Inside the face, the location in the eyelids stands out, an area of the face with thin skin in which we apply many cosmetics, and which alone represents 10% of the total (2).

4. What components of cosmetics cause allergies?

the fragrances are the most common cause of allergy to cosmetics, followed by preservatives and hair dyes (1,2). The cosmetics most related to allergy to fragrances are perfumes. To prevent the degradation of cosmetics, preservatives are added to their composition, which include parabens, the formaldehyde and the isothiazolinones (Kathon) to which the patient can be sensitized.

5. Should I avoid ingredients that cause allergies? Should I use creams without parabens?

Always, if you are sensitized, it is not necessary if you are not. Parabens are the most used preservative in cosmetic products, it is present in practically all of them. Considering its wide use, its sensitization ability is low (1%), even sensitized (allergic) patients tolerate its application in cosmetic creams for daily use in what is called “the paraben paradox” (1).

6. How can I know if I have an allergy to cosmetics?

After a detailed dermatologic history and consultation evaluation, the dermatologist may consider performing the study of allergic dermatitis through “contact tests” or “patch tests”. It involves placing patches with the allergens on the patient's back and observing the reaction that appears on the skin at 48 and 72 hours.

By agreement of experts, in each country the most frequent allergens in the population are selected for the study of contact dermatitis, in what is called "standard battery". Approximately half of the reactions to creams or cosmetics are detected by this battery (1) which includes the perfume mixture Kathon (methylchloroisothiazolinone / isothiazolinone) which is a preservative and paraphenylenediamine (PPD) which is a component of hair dyes.

7. If I use creams with natural ingredients, am I less likely to develop an allergy?

Not, and perhaps even more so, since patients with allergic dermatitis to cosmetics have a high prevalence of sensitization to plant extracts. Tea tree, for example, is a common sensitizer. The main problem is that these ingredients are not well classified on cream labels and their study and identification is more difficult. For this reason, patients with allergies to cosmetics are advised to avoid creams or cosmetics with plant extracts (1).

8. Can sunscreen give me allergies?

YesLike any other cosmetic. Apart from the usual components of cosmetics in sunscreen creams, we find compounds used for this purpose that are capable of causing allergies (oxybenzone, dibenzolmethanes).

We also find the sum of the sun exposure of the contacted area, in which the cream is applied, and the opportunity for a joint effect in what we call "photocontact" (light photo, allergic contact dermatitis). The famous PABA (para-aminobenzoic acid) is practically no longer present in sunscreens on the market.

On the other hand, it is essential to point out that with physical or mineral filters such as zinc oxide or titanium dioxide, no allergies have been described. So, if we want safety on sensitive skin, we will use this type of cream to protect us from the sun (1).

9. The term hypoallergenic creams, what do you mean?

A product to be considered hypoallergenic is a product that you have few chances to cause skin allergy and must (3):

• Not contain any ingredient that has caused allergies in the 1% of the population in the last 5 years and with at least 1000 patients studied.

• Do not contain ingredients for which there is no published data in the last 5 years.

In the current market, approximately 90% of moisturizing creams have at least one contactant or a component capable of causing skin allergy and the current regulation of cosmetics on the market in this regard is limited (4). The term "hypoallergenic" in a cream can be confusedEven creams with this term designed for sensitive or baby skin can contain perfumes or more contaminants that are not present in others or in pure petroleum jelly (5).

The American Contact Dermatitis Association (6) advises patients not to rely on the term “hypoallergenic” and revision the components of the products you use, especially if you are allergic to cosmetics.

10. Are there really intolerant skins?

Yes, there are skins that do not tolerate creams and cosmetic products. As we have seen throughout this text, allergy to cosmetics exists and is not so common in the population. In sensitive skin, which does not tolerate creams and hygiene products, we prescribe suitable products, even when the characteristics of the skin are decisive. The market offers complete lines suitable for this type of skin, which are labeled as "sensitive skin", "intolerant skin", "skin prone to redness", "irritable skin", etc.

References

1. González-Muñoz P, Conde-Salazar L, Vañò-Galván S. Allergic contact dermatitis to cosmetics. Actas Derm Sifiliogr 2014; 105; 822-832.

2. Dinkloh A, Worm M, Geier J, et al. Contact sisitization in patients with suspected contact intolerance: results of the IVDK 2006-2011. J Eur Acad Dermatol 2015; 29: 1071-1081.

3. Zirwas M. Trying to establish “hypoallergenic”. JAMA Dermatol 2017; 153: 1093-1094.

4. Hamman C, Thyssen. Allergen concerns and popular skin care products. JAMA Dermatol 2018; 154: 114-115

5. Harview C, Hsiao J. Allergen concerns and popular skin care products. JAMA Dermatol 2018; 154: 114.

6. Verallo-Rowell. The validated hypoallergenic cosmetics classification system: its 30-year evolution and effect on the prevalence of cosmetic reactions. dermatitis 2011; 22: 80-97.

7. Xu S, Kwa M, Lohman M et al. Consumer preferences, product characteristics, and potentially allergenic ingredients in best-selling moisturizers. JAMA Dermatol 2017; 153: 1099-1105.

8. Chou M, Mikhaylov D, Lazic Strugar. Moisturisers: a basis for comparison between allergens and economic value. Dermatitis 2018; 29: 339-244.

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