Hypersensitivity to hydrogenated lanolin

The number of patients with dermatitis from applied betamcthasone‐17‐valerate ointment, which incorporated hydrogenated lanolin, rapidly increased in Japan after 1971. On patch testing, the incidence of hypersensitivity to hydrogenated lanolin is significantly higher than to anhydrous lanolin at the 1% level, that is, 5.20% (26/502) with the former and 1.99% (10/502) with the latter, although sensitivity to both materials is significantly related at the 0.5% level. The possible explanations considered are that hydrogenated lanolin contains three main allergens: the first is a group of lanolin alcohols which are the common eczematogens in anhydrous lanolin; the second refers to the products of hydrogenation, composed of saturated, easily oxidized, organic substances of low molecular weight; and the third refers to traces of nickel, copper and chromium, as a result of contamination in the hydrogenation process.