Abstract

Background: Ethyl Glucuronide in hair (hEtG) is a commonly used biomarker in the diagnosis of chronic excessive alcohol consumption. Despite high diagnostic specificity, some cosmetic treatments may influence the hEtG concentration, leading to false positive results.

Aim: The aim of this study was to evaluate three cases of alleged false positive hair samples due to the exposure to perfumes.

Methods: Three subjects were monitored for up to 3 years; at least one sample collection was performed each year; all three men declared to have exposed hair to alcohol-based perfumes during the entire period, except for the last three months before last sample collection. A volunteer treated the right side of his scalp every day during a month period with alcohol-based perfumes. Collection of hair was done at both sides before the first sample treatment and at the end of the month. Hair were processed following the method routinely used in the laboratory for the determination of hEtG (double washing with methanol/dichloromethane, pulverization, overnight incubation in water, and LC-MS/MS analysis, LLOQ: 3pg/mg).

Results: EtG levels in hair collected from the three men during the declared exposition period ranged from < 3.0 pg/mg to 1130 pg/mg. hEtG concentrations, at the end of the three-month period without any use of perfumes, were < 3.0 pg/mg for the two men declaring an abstinence from alcoholic beverages and 26.3 pg/mg for the subject declaring an average drinking habit of about 35 g/day ethyl alcohol. Non-treated hair of the volunteer provided negative results, while hEtG levels in treated hair were 14.6 and 24.7 pg/mg.

Conclusion: Prolonged exposition of hair to alcohol-based perfumes may increase hEtG levels, resulting in false positive results.

Keywords: Ethyl glucuronide, hair, alcohol-based perfumes, false positive, analytical methods, hair analysis.

Graphical Abstract