Astronauta

Clinical Toxicology (2011), 49, 886–891
Copyright © 2011 Informa Healthcare USA, Inc. ISSN: 1556-3650 print / 1556-9519 online
DOI: 10.3109/15563650.2011.626425

REVIEW ARTICLE


Inorganic mercury poisoning associated with skin-lightening cosmetic products


THOMAS Y. K. CHAN1,2

1Division of Clinical Pharmacology, Department of Medicine and Therapeutics, Prince of WalesHospital, The Chinese University of
Hong Kong, Shatin, New Territories, Hong Kong, China
2Prince of Wales Hospital Poison Treatment Centre, Shatin, New Territories, Hong Kong, China


Introduction. Mercury and mercury salts, including mercurous chloride and mercurous oxide, are prohibited for use in cosmetic products as skin-lightening agents because of their high toxicity. Yet, the publiccontinue to have access to these products. Methods. Reports of skin- lightening cosmetic products containing mercury and cases of mercury poisoning following the use of such products were identified using Medline (1950 – 28 March 2011) with mercury, mercury compounds, mercury poisoning, cosmetics and skin absorption as the subject headings. These searches identified 118 citations of which 31 wererelevant. Toxicokinetics. The rate of dermal absorption increases with the concentration of mercury and prior hydration of the skin. The degree of dermal absorption varies with the skin integrity and lipid solubility of the vehicle in the cosmetic products. Ingestion may occur after topical application around the mouth and hand-to-mouth contact. After absorption, inorganic mercury is distributed widelyand elimination occurs primarily through the urine and feces. With long-term exposure, urinary excretion is the major route of elimination. The half-life is approximately 1–2 months. Features. The kidneys are the major site of inorganic mercury deposition; renal damage includes reversible proteinuria, acute tubular necrosis and nephrotic syndrome. Gastrointestinal symptoms include a metallictaste, gingivostomatitis, nausea and hypersalivation. Although penetration of the blood–brain barrier by inorganic mercury is poor, prolonged exposure can result in central nervous system (CNS) accumulation and neurotoxicity. Inorganic mercury poisoning following the use of skin-lightening creams has been reported from Africa, Europe, USA, Mexico, Australia and Hong Kong. Nephrotic syndrome (mainly dueto minimal change or membranous nephropathy) and neurotoxicity were the most common presenting features. As mercury-containing cosmetic products can contaminate the home, some close household contacts were also reported to have elevated urine mercury concentrations. Assessment. Prevention from further exposure is the first step. Cream users and their close contacts should be evaluated forevidence of mercury exposure, the presence of target organ damage and the need for chelation treatment. Laboratory evaluation of affected subjects should include a complete blood count, serum electrolytes, liver and renal function tests, urinalysis, urine and blood mercury concentrations. Since blood mercury concentrations tend to return to normal within days of exposure, blood samples are usefulprimarily in short-term, higher-level exposures. Estimation of the urine mercury concentration is the best marker of exposure to inorganic mercury and indicator of body burden. A 24-hour urine for measurement of mercury excretion is preferred; a spot urine mercury concentration should be corrected for creatinine output. Management. Chelation therapy is indicated in patients with features of mercurypoisoning and elevated blood and/or urine mercury concentrations. Unithiol (2,3- dimercapto-1-propanesulfonic acid, DMPS) is the preferred antidote though succimer (dimercaptosuccinic acid, DMSA) has also been employed. Conclusions. The use of mercury in cosmetic products should be strictly prohibited. The public should be warned not to use such products as their use can result in systemic absorption...