Severe aplastic anaemia following the use of hair dye: report of two cases and review of literature

Final Amended Report of the Safety Assessment of Toluene-2,5-Diamine, Toluene-2,5-Diamine Sulfate, and Toluene-3,4-Diamine as Used in Cosmetics

Toluene-2,5-diamine, toluene-2,5-diamine sulfate, and toluene-3,4-diamine are diaminotoluenes used as colorants in permanent hair dyes and tints. Toluene-2,5-diamine is used in 79 products at concentrations up to 3%; toluene-2,5-diamine sulfate is used in 168 products at concentrations up to 4%. Toluene-3,4-diamine does not appear to be in current use. Previously, the Cosmetic Ingredient Review Expert Panel determined that all 3 ingredients were safe for use as hair dyes. New data suggest that differences in toxicity, especially with respect to carcinogenicity, may exist as a function of placement of amine groups around the benzene ring. The Expert Panel concluded that toluene-2,5-diamine and toluene-2,5-diamine sulfate and are safe as hair dye ingredients in the present practices of use and concentrations but that there are insufficient data supporting the safety of toluene-3,4-diamine.

A hospital-based case control study of aplastic anemia in Shanghai, China

We report results of a hospital-based case control study of 137 consecutive patients diagnosed with aplastic anemia (AA) in participating hospitals over a 4-year period. Diagnoses were made by a single laboratory, subjects were age- and gender-matched to two controls and interviewed concerning previous disease, work histories and exposures to potential etiologic agents. Analysis was conducted on two distinct subgroups: severe aplastic anemia (SAA) and moderate aplastic anemia (MAA). In univariate regression models, the strongest associations were observed for exposure to benzene and SAA (OR=3.12, 95% CI=1.12-8.65) and life on a farm and MAA (OR=3.08, 95% CI=1.44-6.56). Benzene exposure did not show a strong dose-response relationship with either subtype. When accounting for all of the potential confounders we considered in conditional regression models, the previous relationships persisted. Other explanatory variables included hair-dye use for MAA and farm exposures, such as livestock for SAA, although most of these additional variables fell just short of statistical significance. Adjusted R-squared values were only 10% for each subtype, leaving 90% of AA occurrence unexplained. Our results suggest that: (a) benzene exposure is more strongly related to SAA than MAA, (b) farm and livestock exposures are related to both forms of AA, confirming some previous results, and (c) a large percentage of AA remains unexplained, which may indicate that individual susceptibility has a major influence on AA occurrence.

A case-control study of aplastic anemia

A case-control interview study of aplastic anemia was conducted to evaluate suspected risk factors. Cases (N = 59) newly diagnosed during 1975-82 at 25 Baltimore area hospitals were compared with 59 individually matched (on age, sex and race) controls selected by random digit dialing. The average educational level was less for cases than controls. The major job-related findings were a significant excess for occupational exposure to paint (OR = 6.1; 95% C.I. = 1.2-29.7), further substantiated by a positive dose-response relationship, although painters were not at excess risk. An increased risk of occupational exposure to viruses (OR = 9.0; 95% C.I. = 0.8-105.6) was noted. Additional evidence implicating viral factors included a significant association with prior history of hepatitis (OR = 9.0; 95% C.I. = 1.0, 84.2) and an elevated risk for pre-diagnostic receipt of blood transfusions (OR = 7.1; 95% C.I. = 0.7-68.4). Risks were not increased for other occupational, residential, personal, or medical treatment exposures or for other viral infections, medical conditions, smoking or alcohol consumption prior to diagnosis. Because of the small number of subjects studied and the multiple comparisons examined, these findings should be interpreted cautiously and confirmation should be undertaken in larger, population-based studies.

Hair dye use and risk of leukemia and lymphoma

Data from a population-based case-control study of incident leukemia and non-Hodgkin's lymphoma among adult men in Iowa and Minnesota were used to evaluate risk associated with hair dye use. The relative risk for ever using hair dyes was 1.8 (95% confidence interval [CI] = 1.1-2.7) among leukemia patients, and 2.0 (CI = 1.3-3.0) among cases with non-Hodgkin's lymphoma. There was a suggestion of increased risk with extent of hair dye use. Given the widespread use of hair coloring products, these observations deserve more detailed evaluation in populations where the exposure is relatively common.