Abstract
Lanolin and its derivatives (24 test samples) were patched for 48 hours on the backs of 430 subjects including patients with cosmetic dermatitis, facial melanosis, a history of cosmetic dermatitis or other types of eczema and dermatitis, non-eczematous dermatosis, and on healthy volunteers. Although refined lanolin fatty acid (30%) produced the most frequent positive reactions, these reactions were found to result from irritant reactions to low molecular lanolin fatty acids. Moderately strong positive reactions which are thought to be allergic reactions were observed to lanolin alcohol (30%) in 2.3%, to reduced lanolin (30%) in 1.3%, to lanosterol (10%) in 1.3%, to polyoxyethylene lanolin alcohol (30%) in 0.9%, to acetylated lanolin alcohol (30%) in 0.8% and to refined lanolin (30%) in 0.5%. In 7 with refined lanolin produced postive reactions 72 hours after application, 5 had positive reactions to lanolin alcohol (30%), 1 to lanosterol (10%), 1 to polyoxyethylene lanolin alcohol (30%), 1 to acetylated lanolin (30%), 1 to polar lanolin (as is), and 1 to isopropyl lanolin fatty acid esters (30%). From these patch test results, lanolin alcohol was thought to be most often responsible for allergic reactions to lanolin. It was also determined that absorption refined lanolin, in which free lanolin alcohol and lanolin wax had been removed, was safer than refined lanolin or partly refined lanolin.
