title: Diagnosis and prevalence of lanolin allergy.
abstract: BACKGROUND
  Current evaluation of suspected allergic contact dermatitis to lanolin includes patch testing to lanolin alcohol (30% in petrolatum). Using this method, the prevalence of lanolin allergy is low (1.8%-2.5%).
  
  
  OBJECTIVE
  The objective of this study was to determine whether patch testing to a single lanolin derivative results in underdiagnosis compared with patch testing to 12 lanolin derivatives.
  
  
  METHODS
  Patients were prospectively patch tested to (1) lanolin alcohol (30% in petrolatum) in our standard allergen series; (2) Amerchol L101 (50% in petrolatum) in our cosmetic series; and (3) 10 lanolin derivatives (using concentrations and vehicles recommended in the literature) in a supplemental series.
  
  
  RESULTS
  Of 286 patients, the overall prevalence of positive reactions to lanolin in at least 1 of the 3 patch test series was 6.29% (95% confidence interval [CI], 3.48%-9.11%) (n = 18). The prevalence rates of lanolin allergy using the standard, cosmetic, and supplemental series were 1.05% (95% CI, 0%-2.23%), 3.85% (95% CI, 1.62%-6.07%), and 3.85% (95% CI, 1.62%-6.07%), respectively. Amerchol L101 was associated with increased reaction rates compared with the standard (odds ratio, 3.81; P = 0.007) and supplemental (odds ratio, 8.85; P < 0.001) series, whereas reaction rates were similar for the standard and supplemental series (P = 0.78).
  
  
  CONCLUSIONS
  Amerchol L101 and patients' own products should be added to a standard patch testing allergen series to adequately identify lanolin allergy.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Rachel Y N
authors.initials: RY
authors.lastname: Miest
authors.forename: James A
authors.initials: JA
authors.lastname: Yiannias
authors.forename: Yu-Hui H
authors.initials: YH
authors.lastname: Chang
authors.forename: Nidhi
authors.initials: N
authors.lastname: Singh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007809:Lanolin / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods*; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D007809:Lanolin