Allergic Contact Dermatitis from Vitamin E: The Experience at Mayo Clinic Arizona, 1987 to 2007

Discussion

According to the Environmental Working Group's Skin Deep cosmetic safety database, more than 14,000 currently marketed products contain tocopheryl acetate or tocopherol. ^[3] These compounds are found in moisturizers, sunscreens, lip products, foundations, cleansers, conditioners, and other topical products. With the recent heightened interest in anti-aging and rejuvenation, this number likely has increased in the past decades. We initially hypothesized that we would identify a corresponding increase in cases of allergic contact dermatitis with time. However, we found no evidence of increased incidence of allergic contact dermatitis when we compared the initial patch-test data (1987 to 1999) with more recent data (2000 to 2007).

This study used a small population and included data from only two centers. Additionally, because exact concentrations of vitamin E were not recorded from 1997 to 1999, we were unable to analyze the effects of changes in the concentration of patch-test products over the years.

"Vitamin E" is a general term used to denote a family of eight antioxidants (four tocopherol compounds and four tocotrienol compounds); stereoisomers of individual compounds also exist.^[4] Additionally, because vitamin E chemicals are antioxidants, they are unstable compounds that are typically esterified to facilitate stability among other chemicals.^[5] Thus, α-tocopherol acetate is actually α-tocopherol that has been esterified by acetic acid. Esters must be hydrolyzed for activity, and this is easily accomplished in the human body.

Contact allergy to vitamin E was reported in 1965: an 18-year-old female developed dermatitis on her earlobes, where she had been applying a salve that contained vitamin E.^[6] Patch testing with the ingredients of the salve revealed a clinically significant reaction only to α-tocopherol. Subsequently, many other cases of allergic contact dermatitis from tocopherol acetate and linoleate were reported,^[7–12] including an epidemic outbreak in Europe that was ascribed to the inclusion of tocopherol in cosmetic preparations.^[13]

In addition to allergic contact dermatitis, contact urticaria^[14] and erythema multiforme–type eruptions^[15] have been reported in connection with vitamin E. One report describes a xanthomatous reaction following a suspected contact dermatitis from vitamin E.^[16] According to Fisher's Contact Dermatitis, vitamin E almost never causes reactions when taken systemically, but it can cause contact urticaria when applied to the skin.^[17]

The contact dermatitis in our study's patients consisted mainly of (1) dermatitis on the face or extremities or (2) a generalized eruption. This is consistent with the reports of allergic contact dermatitis from vitamin E in the literature.^[9,10,13,15]

The North American Contact Dermatitis Group (NACDG) reported a 1.1% rate of positive patch-test reaction to dl-α-tocopherol 100% in 2003 to 2004 and a relative rate of 1.00 in 2001 to 2002. Before 2001, dl-atocopherol 100% was not tested as part of a standard series.^[18] dl-α-Tocopherol was on the NACDG's list of the 20 most common allergens in cosmetics from 2001 to 2004; 3.1% of women and 0.6% of men had positive patchtest reactions to vitamin E that were attributed to a cosmetic not otherwise specified.^[19] This implies that users of cosmetics may have a greater risk of contact dermatitis than the general population.

In 2003, Oshima and colleagues described a young woman who had a positive patch-test reaction to dltocopheryl nicotinate but negative patch-test reactions to dl-a tocopherol and nicotinamide.^[20] This implies that in some patients at least, there is antigen specificity within the vitamin E group. Thus, patients should be patch-tested with their own products. Patch testing with only α-tocopherol may be inadequate when evaluating allergic contact dermatitis from the other isomers or esters that make up the vitamin E family.^[21]

An additional complicating factor in testing for allergic contact dermatitis from vitamin E is the fact that vitamin E is an antioxidant. This implies that it has the ability to minimize inflammation; in fact, animal models have shown that vitamin E derivatives can effectively suppress contact dermatitis.^[22] A guinea pig study has also shown that sensitization to contact allergens can be reduced when an antioxidant preparation containing vitamin E is used.^[23] Additionally, vitamin E is known to have photoprotective effects^[24] and antiinflammatory effects^[25] in mouse models.

Vitamin E derivatives in various products may actually suppress contact dermatitis; one such suspected case has been reported.^[26] dl-α-Tocopherol acetate has been used to decrease paresthesias from synthetic pyrethroids in humans, and investigators speculated that this effect may stem from antiinflammatory properties of vitamin E.^[27]

Because of the role of vitamin E in the human body and because of its antioxidant properties, vitamin E and its derivatives likely will appear on ingredient lists for years to come. Although some patients will develop contact dermatitis after exposure to the ingredient, our findings suggest that this is rare. The results of future studies investigating the ability of vitamin E to act as both an allergen and a suppressor of contact allergy perhaps would allow physicians and scientists to exploit the positive effects of the antioxidant while avoiding the adverse contact dermatitis.

Dermatitis. 2010;21(4):199-202. © 2010 American Contact Dermatitis Society

Cite this: Allergic Contact Dermatitis from Vitamin E: The Experience at Mayo Clinic Arizona, 1987 to 2007 - Medscape - Aug 01, 2010.