A retrospective analysis of contact allergy to lanolin

ABSTRACT

Background  Lanolin is often stated to be an important sensitizer but some of the available literature is based on the analysis of high-risk patients.Objectives  To analyse the frequency of contact allergy to lanolin (wool alcohols) in a central London teaching hospital patch-test population.Methods  Review of 24,449 patients recorded on our database during 1982–96 who were tested with a standard series containing 30% wool alcohols.Results  The mean annual rate of sensitivity to this allergen was 1·7%. The wool alcohols-allergic group contained a higher proportion of females (P < 0·05), and the mean age of both males and females (48·4 and 49·2 years) was higher than that of non-wool alcohols-allergic patients (41·4 and 35·9 years; P < 0·0005). There was no difference in atopic eczema status between these groups. The highest prevalence of allergy to wool alcohols was among patients with lower leg dermatitis (6·0%; 95% confidence interval, CI 4·46–7·54), followed by those with anogenital dermatitis (3·23%; 95% CI 1·81–4·65). There was an unexplained decline in the rate of positive patch tests to Amerchol^® L-101. However, some patients who reacted to this were negative with wool alcohols, so it may be a useful additional test reagent. The mean rates of allergy to Eucerin^® (0·65% per annum) and 50% hydrogenated lanolin in petrolatum (1% per annum) were low, and we no longer use these as test reagents.Conclusions  This study illustrates that lanolin sensitization has remained at a relatively low and constant rate even in a high-risk population (i.e. patients with recent or active eczema).