title: Differences in contents of organochlorine impurities do not influence responses to patch testing with Majantol®.
abstract: BACKGROUND
  Majantol® [2,2-dimethyl-3-(3-methylphenyl)propan-1-ol; CAS no. 103694-68-4] has been identified as a contact allergen in humans, despite negative animal tests. Hence impurities, specifically organochlorines, in Majantol® might have been the reason for positive patch test reactions in the past.
  
  
  OBJECTIVE
  To assess elicitation via patch testing with a standard market-quality version of Majantol® ('normal') with a normal content of organochlorine impurities, as compared with an ultra-purified version of Majantol® ('pure'), without detectable organochlorine impurities.
  
  
  METHODS
  Between 1 October 2013 and 31 December 2014, two different Majantol® patch test preparations of the above-mentioned quality were tested 5% pet. in parallel in the 'monitor series', that is, together with the baseline series, in 8005 consecutive patients from 33 departments of dermatology of the Information Network of Departments of Dermatology (IVDK).
  
  
  RESULTS
  Fifty-three of 7740 [0.69% (95%CI: 0.51-0.87)] patch tested patients reacted to at least one Majantol® preparation. The majority (n = 32) (60.4%) reacted to both preparations, 13 (24.5%) reacted to the 'normal' version only, and 8 (15.1%) reacted to the 'pure' version only. There was good concordance between results [Cohen's kappa 0.75 (95%CI: 0.65-0.85)], and there was no significant difference in frequency or intensity between the two preparations. More doubtful or irritant reactions than positive reactions were observed, and> 80% of all positive reactions were weak positive.
  
  
  CONCLUSIONS
  Organochlorine impurities are very probably not the cause of allergic reactions to Majantol®.
authors.affiliation: Information Network of Departments of Dermatology (IVDK), 37075, Göttingen, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Schnuch
authors.affiliation: Symrise AG, 37603, Holzminden, Germany.
authors.forename: Boris P
authors.initials: BP
authors.lastname: Müller
authors.affiliation: Information Network of Departments of Dermatology (IVDK), 37075, Göttingen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Geier
mesh_terms: D000485:Allergens / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000209:etiology*; D004340:Drug Contamination; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000009:adverse effects*; D010328:Patch Tests; D014050:Toluene / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D000485:Allergens; D006843:Hydrocarbons, Chlorinated; C522135:majantol; D014050:Toluene
keywords: 2,2-dimethyl-3-(3-methylphenyl)propan-1-ol; CAS no. 103694-68-4; Majantol®; allergic contact dermatitis; clinical epidemiology