When used “as is,” lanolin is thought to be a weak allergen. This raises concern that using pure lanolin in patch tests may produce many false-negative reactions.[1,28] Early dermatologists experimented with different methods, using lanolin, eucerin, and varying concentrations of wool alcohols with or without the addition of keratolytics.[1,26–28,66–68] Since the late 1960s, 30% wool alcohols have been advocated as the standard for patch testing.
The use of more than one patch-testing substance for detecting lanolin allergy is important, and the use of AL-101 (100%) has been reported to cause fewer irritant reactions. Mortenson tested 899 patients undergoing patch testing with wool alcohols, hydrogenated lanolin, Eucerin, and AL-101. Of those tested, 6.7% were positive to at least one of these allergens; approximately half of these would have been missed if only wool alcohols had been used. More evidence for the use of AL-101 in patch-testing came out of a 1997 Belgian study. Matthieu and Dockx reported two groups of patients with dermatitis who were tested with a standard series containing wool alcohols (30% pet) and AL-101 (100%). In the first group, 45 (11.5%) of 393 patients had positive reactions to wool alcohols or AL-101 (100%) or both: 32 reacted to only AL-101 (100%), 1 reacted to only wool alcohol, and 12 reacted to both. The second group was tested with wool alcohol (30% pet), AL-101 (100%), and AL-101 (50%). Of the 28 patients who reacted to at least one of these compounds, 9 reacted only to AL-101 (100%), 8 reacted only to AL-101 (50%), 5 reacted to both the 50% and 100% concentrations of AL-101, 1 reacted to only wool alcohol, and one reacted to both wool alcohol and AL-101 (100%) (results for the remaining 4 patients were not reported).
In the 1989 Swedish study by Edman and Moller, 33 patients with previously reported positive patch-test reactions to wool alcohols, AL-101, or both were retested with wool alcohols (30% pet); AL-101 (as is); Ameralk (Amerchol), the alcoholic fraction of AL-101 (7% pet); white petrolatum; Decubal cream (Alpharma, Bridgewater, NJ) (as is); and Golden Fleece (Alpharma), a form of purified anhydrous lanolin found at a concentration of 6% in Decubal. Twenty-five percent of these patients would have been missed if only 30% wool alcohols or AL-101 had been used whereas only 10% would have been missed if both AL-101 and wool alcohols had been used. Of the six test substances used, Ameralk caused positive reactions in 85% of the 20 patients who had positive reactions to the lanolin products. Currently, most patch-test experts use both 30% wool alcohols and AL-101 for the detection of lanolin allergy.
Dermatitis. 2008;19(2):63-72. © 2008 American Contact Dermatitis Society
Cite this: Lanolin Allergy: History, Epidemiology, Responsible Allergens, and Management - Medscape - Apr 01, 2008.