Contact allergy to lanolin: temporal changes in prevalence and association with atopic dermatitis

Background. Lanolin has been tested as lanolin alcohols (30% pet.) in baseline patch test series since 1969, and this has shown clinically relevant allergic contact dermatitis cases. Objectives. To investigate the temporal development of lanolin allergy (i.e. positive reaction to lanolin alcohols and/or Amerchol (TM) L-101), and the association between contact allergy to lanolin and patient characteristics from the MOAHLFA index. Methods. A retrospective observational study of consecutively patch tested dermatitis patients (n=9577) between 1 January 2004 and 31 December 2015 with lanolin alcohols 30% pet. and Amerchol (TM) L-101 50% pet. was performed. Results. The prevalence of lanolin allergy increased from 0.45% in 2004 to 1.81% in 2015. In age-adjusted and sex-adjusted analyses, weak, significant associations were found between atopic dermatitis and lanolin and lanolin alcohols allergy, respectively, but no association with Amerchol (TM) L-101 allergy was found. Among 9286 dermatitis patients who were tested with both allergens, 108 had a positive test reaction to either lanolin alcohols or Amerchol (TM) L-101, whereas only 29 patients had positive test reactions to both markers. ConclusionsThe prevalence of lanolin contact allergy has increased over a 12-year period, and inclusion of Amerchol (TM) L-101 will increase the chance of detecting lanolin contact allergy. Patch testing with lanolin is helpful in atopics with dermatitis and suspected cosmetic allergy.