Aminoethylethanolamine: a new allergen in cosmetics?

Amphoacetates are organic compounds used in many industrial applications and in cosmetic formulations for the skin, hair and mucosa, as surfactants, mild foaming and cleansing agents in concentrations ranging from 0.1% to 50%. Despite the fact that they have been in use for many years, cases of contact allergy to them are extremely rare. We describe 4 patients who developed an eczematous reaction after use of detergents containing amphoacetates. Patch testing showed positive reactions to sodium lauroamphoacetate (Miranol HM Special, Rhodia, England) as is or diluted at decreasing concentration (10%, 5% and 1%) in water and to aminoethylethanolamine (AEE) at the concentration of 1% in various vehicles (ethanol, acetone, and sodium laurylethersulfate 1% aqueous solution) and at decreasing concentrations ranging from 1% to 0.005% in water. AEE is one of the reagents used in the synthesis of amphoacetates. This molecule, that is structurally an ethylenediamine derivative, has sensitizing power and is reported as a cause of occupational contact allergy in cable jointers. Combined eczematous reactions to AEE and sodium lauroamphoacetate can be consequent to the presence of the former substance as an impurity in amphoacetates-containing products, as demonstrated by ion chromatography-mass spectrometry analysis.