title: Assessment of balsam of Peru patch tests.
abstract: To find an ideal test technique for as low a dose of balsam of Peru (Myroxylon Pereirae) as possible, subjects testing positive to balsam of Peru are re-tested with a 25% concentration of balsam of Peru in petrolatum. Applications are with Finn Chambers for 6 different application times, and directly by foils for 96 h (4 days (D)). The goals are to confirm which subjects are positive and which are not, and, using that information, to see if it is possible to distinguish between these 2 groups, tested concomitantly at much lower serial dose levels, in terms of perfusion or by visual assessments. 5 different serial doses are applied with strips for 3-96 h (4D) and with foils for 96 h (4D). The Finn Chamber tests allow a distinction between visually positive and negative subjects supported by perfusion assessments. With the foils, a 24x lower serial dose level than with the 25% test substance is sufficient to distinguish between positive and negative subjects in terms of perfusion values. This approach requires readings up to 9 days. With this test, the visual approach yields only 3 of 10 positive subjects. This study demonstrates that a lower test dose is possible with perfusion assessments compared to visual ones.
authors.affiliation: Department of Dermatology, Karolinska Hospital, Stockholm, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Bjarnason
authors.forename: E
authors.initials: E
authors.lastname: Flosadóttir
authors.forename: T
authors.initials: T
authors.lastname: Fischer
mesh_terms: D000328:Adult; D000485:Allergens / Q000008:administration & dosage / Q000009:adverse effects*; D001453:Balsams / Q000008:administration & dosage / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000209:etiology* / Q000503:physiopathology; D004890:Erythema / Q000139:chemically induced* / Q000503:physiopathology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D017551:Microdialysis / Q000295:instrumentation; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods*; D010477:Perfusion; D010860:Pigments, Biological / Q000008:administration & dosage / Q000009:adverse effects*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012867:Skin / Q000098:blood supply / Q000187:drug effects*
chemical_list: D000485:Allergens; D001453:Balsams; D010860:Pigments, Biological; C025080:Peruvian balsam