Simultaneous sodium lauryl sulphate testing improves the diagnostic validity of allergic patch tests. Results from a prospective multicentre study of the German Contact Dermatitis Research Group (Deutsche Kontaktallergie-Gruppe, DKG)

摘要: Summary Background  There is evidence that a higher skin susceptibility may induce nonspecific erythematous or weak positive reactions to contact allergens in patch testing. Objectives  To evaluate whether simultaneous application of sodium lauryl sulphate (SLS) along with diagnostic tests can provide information regarding irritability which help discriminate allergic from irritant allergens. Methods  Between July 2001 and June 2003, this prospective study collected test data 5971 patients 19 centres Germany Austria the Information Network Departments Dermatology (IVDK). In addition (standard series eight known ‘problematic’ low reaction index high positivity ratio: 1,3-diphenylguanidine, amerchol L-101, benzalkonium chloride, benzoyl peroxide, cocamidopropyl betaine, octyl gallate, phenyl mercuric acetate propylene glycol), patches SLS 0·5% 0·25% aq. were applied. Reactions analysed at IVDK centre. The association between an certain allergen was assessed logistic regression analysis, same time controlling for influence age sex. Results  Of 29 standard series, 23 21 gave percentage SLS, respectively, comparison SLS-negative patients. All increased reactions. Similarly, 22 seven rections (exception: gallate). For most allergens, markers (reaction ratio) worse SLS-positive Differences more pronounced when testing than 0·5%. Conclusions  Because there convincing (evaluated by test) degree deciding doubtful weakly ‘positive’ should be interpreted as irritant.