Background Patch-test readings after day 5 have previously been used to identify delayed reactions to metals and topical antibiotics. Objective The aims of this study were to identify allergens for which late readings (beyond day 5) would be most valuable and to compare our results with our previous study on delayed patch-test readings. Methods This was a retrospective study of 298 patients who underwent metal and corticosteroid series patch testing from January 1, 2007, through December 31, 2013. Patch-test readings were conducted on days 3 and 5 and at least once sometime between days 7 and 14. All reactions were examined at each reading. Conclusions These results were concordant with our previous findings that additional readings after day 7 are particularly useful for identifying reactions to metals (gold, cobalt, beryllium, palladium), specific preservatives (dodecyl gallate, propolis), and the topical antibiotic neomycin. New delayed reactions to bacitracin, p -phenylenediamine, and topical corticosteroids were not seen in this cohort.
Background Patients with a sore or burning mouth associated with clinically normal oral mucosa present a difficult diagnostic challenge. Objective The objective of this study was to assess the value of patch testing in patients with burning mouth syndrome. Methods We retrospectively reviewed the results of patch testing to an oral series in patients with burning mouth syndrome seen at Mayo Clinic, Rochester, Minnesota, between January 2000 and April 2006. Results Of 195 consecutive patients with a burning or sore mouth, 75 had patch testing to an oral series, and 28 of these patients (37.3%) had allergic patch test reactions. The most common allergens were nickel sulfate hexahydrate 2.5%, balsam of Peru, and gold sodium thiosulfate 0.5%. On follow-up, 15 patients reported improvement, 4 removed or avoided the offending dental metal, and 6 avoided the dietary allergen. Thirteen patients did not improve; 6 avoided identified allergens, but without improvement; 1 removed dental metals without symptom change; and 5 avoided test-positive dietary allergens but without improvement. The remaining 7 nonresponders had nonrelevant patch test results or did not avoid allergens. Conclusions Patch testing can identify patients who may be allergic to dental metals or dietary additives and who may benefit from removal or avoidance of these.