Contact allergy to beryllium chloride: report of 12 cases.

BACKGROUND Isolated cases of allergic contact dermatitis, gingivitis and stomatitis caused by beryllium have been previously reported. We have been able to study a series of 12 patients with patch test reactions to beryllium chloride. OBJECTIVES The study was aimed at defining the clinical and patch testing characteristics in this group of patients, and determining whether some were delayed elicitation reactions or late reactions of active sensitizations by patch testing. MATERIAL AND METHODS We performed a 5-year retrospective study of patients tested with a metal series, and studied a subgroup who showed reactions to beryllium chloride. RESULTS A total of 1799 patients were patch tested, 62 of whom were also tested with a specific metal series; 12 of them reacted to beryllium chloride. Eight of the 12 patients showed reactions to other metals. Based on the time of positive reaction to beryllium chloride, three patterns emerged: (i) 3 patients showed positive reactions on D2-D4; (ii) 6 patients showed positive reactions between D7 and D10; and (iii) 3 patients showed positive reactions later than D10. CONCLUSIONS Contact allergy to beryllium chloride may not be as unusual as the literature suggests. In order to avoid undetected contact allergies, we recommend performing later readings, between D7 and D10, whenever patch testing is performed with beryllium chloride. Active sensitization may occur.