In the past 4 years, a high incidence (118/362) of positive patch test reactions to E45 cream were noted in 2 patch testing clinics. 18/54 of those patch tested to all the ingredients demonstrated allergies to ingredients. The most frequent was triethanolamine; lanolin allergy occurring in only 1 patient. The remaining reactions may be explained as irritant reactions resulting from triethanolamine stearate (TES) formation within the cream. The irritancy of triethanolamine stearate was demonstrated in patients and controls. Conductivity studies showed that TES arises from the combination of the ingredients triethanolamine and stearic acid. The formulation of E45 cream was being changed at the time of writing, with the removal of triethanolamine from the product.