252 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Quaternium-15, imidazolidinyl urea, and DMDM hydantoin are formaldehyde donors. The latter is used less frequently than the other two compounds. Quaternium-15 has been shown to be a more active formaldehyde releaser than imidazolidinyl urea (19). Allergic reactions may be elicited by the compound per se or by the released formaldehyde (21, 22). Fisher (23) maintains imidazolidinyl urea is a much safer preservative than quaternium-15 for formaldehyde-sensitive individuals. Potassium sorbate is also used as a preservative in eye area products. Sensitization to this agent is reported (24). Antioxidants: Butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA)per se or BHA in combination with propyl gallate and citric acid in propylene glycol (Tenox II ©) are found in hydrous and anhydrous formulations. Each component including the vehicle (propylene glycol) of Tenox II © has been implicated in hypersensitivity reactions (25-28). Resins: Dehydroabietyl alcohol (Abitol ©) is a notorious sensitizer that may cross react with abletic acid in adhesive and with rosin (colophony) (29, 30). Miscellaneous allergens: Propylene glycol is used infrequently in eye area cosmetics. This solubilizer and antimicrobial agent is more likely to induce subjective irritation or irritant contact dermatitis than allergic contact dermatitis (31). Allergic reactions to propylene glycol are reported (28, 32). Hydrogenated lanolin and lanolin oil are used at times in eye area cosmetics. Hypersensitivity to hydrogenated lanolin has been shown to be greater than to anhydrous lanolin (33). Nickel: Eye cosmetics contaminated with nickel have been the cause of eyelid dermatitis in nickel-sensitized women. Levels of nickel as high as 250 ppm (atomic absorption spectometry) have been found in iron oxide pigments (34). Fragrance is rarely used. 4. IRRITANTS IN EYE AREA COSMETICS The irritancy potential of propylene glycol was recognized before its allergenicity (31). Soap emulsifiers, surfactants, and solvents other than propylene glycol are among the known irritants. It is anticipated that other mild irritants may be recognized in time (11). 5. ASCERTAINING THE CAUSE OF CONTACT DERMATITIS Finding the cause may be difficult, especially when more than one product is suspect, not an unusual situation. A systematic approach such as the one outlined below may be considered. Step 1: A carefully taken history of exposure is of paramount importance. It should include inquiry as to agents other than eye area cosmetics that are known to elicit contact dermatitis, the introduction of a new product, and the renewal or refill of a

REACTIONS TO EYE COSMETICS 253 previously used product. How the eye cosmetic is removed is also germane. Exposure to a facial cleanser (cream, lotion, wet facial tissue) or eye makeup remover affords opportunity for contact with potential irritants and allergens. Whether or not the consumer has experienced a similar reaction to other brands of the same product is likewise significant. A positive response suggests an ubiquitous ingredient or a hyper-reactive individual. If the history is ambiguous it may be advisable for the patient to submit all her cosmetics for consideration or possible testing. Step II: The Provocative Use Test--the suspected product is applied to the normal skin of the cubital fossa or back of the ear twice daily for a period of five to seven days. A positive reaction serves to identify the causative product. A negative reaction, on the other hand, does not exonerate a product since the eye area is more sensitive than the test site and actual use is only approximated. Step III: Patch testing with the ingredients of the relevant product, i.e., the product incriminated by history and/or identified by the provocative use test. Assuming that the test is properly performed and the results are properly interpreted the causative allergen may be identified or verified by this technique. Patch testing, however, is of little or no help in identifying irritants. Because of the occlusive nature of the method false positive reactions are prevalent. The diagnosis of irritant dermatitis remains a diagnosis of exclusion made by history and negative patch tests for allergy. It should be emphasized that patch testing is a deceptively simple technique that requires experience, particularly in the reading and interpretation of the results. (35, 36). Moreover, precise patch testing information, i.e., concentration and type of vehicle, is lacking for many cosmetic ingredients (37). A good deal of unnecessary and unrewarding testing can be eliminated by a detailed history and the provocative use test. 6. MANAGEMENT OF ALLERGIC AND IRRITANT CONTACT DERMATITIS Comprehensive care includes appropriate topical therapy, discontinuance of the offending cosmetic, a sine qua non, and a suitable replacement or substitute whenever feasible (vide infra) for the individuals who desire to wear eye makeup. Cosmetic manufacturers play an important role by providing appropriate patch test materials when requested and by assisting the physician and/or the consumer in finding an alternate product. While a hit or miss change in brand may resolve some problems, selection of a replacement based on identification of the cause is more likely to succeed (38). a) Replacement products for allergic contact dermatitis Allergen replacement has been proposed by others as a means of circumventing allergic contact dermatitis (39). This principle applies to eye area products with the exception of parabens which are almost uniformly present. While substitution is not possible for parabens, three paraben-free eye area products are currently available: Soft Pressed Eyeshadow ©, Resistant Eyeliner ©, and Basic Eye Emphasizer © which also serves as eyeshadow, lid liner, and brow definer (Clinique). Consumers should be instructed to read ingredients disclosures carefully since formulations are subject to change.