Cosmetic dermatitis reactions comprise of mainly irritant and allergic contact dermatitis, contact urticaria and photo allergic reactions. Most cases are of irritant contact dermatitis.

Skin care products and facial make up are the most common causes. The most common responsible allergens are fragrances and preservatives. It is important to monitor the adverse effects of cosmetics, due to their widespread and increasing use.

The development of contact dermatitis depends on nature of the responsible substance, contact site, skin barrier condition, contact duration and frequency of contacts. Cosmetic dermatitis often occurs after repeated applications or application on damaged skin.

Epidemiology

Though the use of cosmetics is widespread, the prevalence of cosmetic dermatitis is relatively low. Nevertheless, it is significant because it is often not detected.

Latest studies show that contact dermatitis is prevalent in 1% of the US. and European populations. Actual prevalence is probably higher since many cases are not reported. In a patch tested study the prevalence was 9.8%. The prevalence is increasing, probably due to increasing use of cosmetics and allergenic ingredients and better accessibility to patch testing. Risk factors are mostly related to increased use of cosmetics. Most people affected are between the ages 20 and 55 and are women.

Clinical features

Contact dermatitis occurs at the site of allergen contact and shows pruritic papules, vesicles or bulae and eczematous dermatitis. Chronic eczematous dermatitis is more common than other features since most cosmetic allergens are relatively weak. In more than half the cases, the face and the area around the eye are affected. It is possible that a cosmetic applied on the face may affect only the region around the eye, since the skin is thinner at that site.

The site of occurrence usually indicates the culprit allergen. The offending allergen may not be obvious in cases where the cosmetic dermatitis is induced by contaminated articles of use, such as, towels, pillows and telephones.

Responsible allergens

Fragrances: Fragrances have consistently proved to be the most common cause of cosmetic dermatitis, indicating the high presence of fragrances in commercial products. Most reactions are due to fragranced skin care products. Actual fragrance products, such as, perfumes, toilet water and colognes rarely cause contact dermatitis. A study found that women are 1.3 times more likely to be allergic to fragrance products than males, probably because they are more exposed to fragrances in cosmetics and household products.

Preservatives: Preservatives prevent the overgrowth of microorganisms and are essential because many cosmetics are multiuse products and come into repeated contact with the environment and the human skin. Preservatives can be antimicrobials, antioxidants or ultra violet absorbers. Preservatives have been repeatedly shown to be one of the two most common causes of cosmetic dermatitis

Formaldehyde: Formaldehyde is an inexpensive preservative having good antimicrobial properties. It is rarely used in cosmetics because it is a frequent sensitizer. But formaldehyde sensitization levels remain high due to its use in cleaning agents and in formaldehyde releasing products. Formaldehyde sensitive patients often have chronic cosmetic dermatitis because the product is difficult to avoid, being present in many products which are frequently encountered. These products may have, instead of formaldehyde, products which release or degrade into formaldehyde.

Formaldehyde releasers: These preservatives include 2-bromo 2-nitropropane 1, 3-diol DMDM hydantoin and diazolidinil urea. By themselves they are basically antibacterial and antifungal but also act by releasing formaldehyde. Allergic reactions can be caused by the preservatives, formaldehyde or both.

Antioxidants: Antioxidants protect products by preventing the deterioration of unsaturated fatty acids present in them. Deterioration can produce a rancid odor and discoloration. Antioxidants are used in lipsticks, lip balm and salves. They can be found in creams and lotions also.

UV absorbers: Chemicals which are UV absorbers are used in cosmetics to prevent product deterioration and to function as a sunscreen. This sunscreen causes cosmetic dermatitis. Oxybenzone is the most common sunscreen in use today.

Pigments: Agents used for coloring cosmetics can also cause contact dermatitis. They are called D&C colors referring to their use in drugs and cosmetics. These colors can cause adverse reactions. Iron oxides, as pigments, are also used in lipsticks and eye makeup, but have rarely been reported for any adverse reactions.

Noncosmetic allergens: Gold, nickel and rubber are three important noncosmetic allergens, which mimic cosmetic allergy. Gold causes patchy facial or eyelid dermatitis, nickel, used in eye cosmetics causes eyelid dermatitis and rubber used in cosmetic applicators causes eczematous reactions.

Management

Avoidance of sensitizing allergens is the key to successful management of cosmetic dermatitis. In the US, the FDA has taken a significant step in helping consumers avoid these allergens by requiring all ingredients to be listed on all direct cosmetic products.