Skin-lightening creams are a possible exposure risk for systemic lupus erythematosus: Comment on the article by Finckh et al
Version of Record online: 27 APR 2007
Copyright © 2007 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 56, Issue 5, page 1721, May 2007
How to Cite
Pollard, K. M. and Hultman, P. (2007), Skin-lightening creams are a possible exposure risk for systemic lupus erythematosus: Comment on the article by Finckh et al. Arthritis & Rheumatism, 56: 1721. doi: 10.1002/art.22560
- Issue online: 27 APR 2007
- Version of Record online: 27 APR 2007
To the Editor:
We read with great interest the article by Finckh et al (1) in which the authors reported an association between silica exposure from urban industrial occupations and the risk of systemic lupus erythematosus (SLE). As noted, the study population comprised economically disadvantaged communities in Boston neighborhoods, of which more than three-quarters of the female residents are of African American descent; as noted by the authors, persons with this ethnic background have an increased incidence of SLE compared with white individuals.
As appreciated by Finckh et al (1), it is difficult to control for all possible environmental and/or occupational exposures that may contribute to disease development. In this regard, we wish to draw attention to one possible exposure risk that may go unreported in studies of populations of color: the use of skin-lightening creams to reduce skin pigmentation. Almost half of such preparations have levels of mercury >1 ppm (mg/kg) (2), and topical application of the most commercially successful cream, sold in more than 35 countries, produces mercury levels in the kidneys of mice (3) equal to those found to accelerate idiopathic autoimmunity in lupus-prone strains (4). Significantly, the mercury levels achieved are equivalent to the levels found in humans with nonoccupational exposure (e.g., dental amalgams) (5). Although the offending cream, “Fair and Lovely” (produced by Hindustan Lever of India), has not been made accessible to American markets by the US Food and Drug Administration, it is easily purchased online and is legally available to millions of consumers in a multitude of other countries.
Adverse health effects due to the presence of mercury in skin-lightening creams have been known since at least the 1970s (6). The major consequence appears to be immune complex–mediated membranous glomerulonephritis (7) or an idiosyncratic nephrotic syndrome (8) associated with a minimal-change renal glomerular lesion that usually spontaneously remits upon discontinuing the offending cream (6). In the most recent case report, the patient had a low titer of antinuclear antibodies (9); this is not an uncommon finding following mercury exposure (10). Although data on occupational exposure have raised the suggestion of an association between mercury and SLE (11), to our knowledge no definitive studies have been performed. Animal studies, however, clearly document that the immunologic response to mercury is strongly controlled by genetic background and varies from minimal lymphoid alterations to overt systemic autoimmunity (12). Because low-dose mercury can accelerate lupus in susceptible mice (4), we believe the greatest effects of mercury-containing skin-lightening creams might be on age at onset and/or severity of disease as opposed to an increase in overall disease prevalence.
K. Michael Pollard PhD*, Per Hultman MD, PhD, * The Scripps Research Institute, La Jolla, CA, Linkoping University, Linkoping, Sweden.