Literature review of aggregated evidence (umbrella review) on the allergy potential of chlorhexidine mouthrinse solutions.

Chlorhexidine is the gold standard for chemical biofilm control in dentistry. As with all therapeutic agents, side effects should be considered, which may include allergic reactions. The present review focused on the allergy-causing potential of dental CHX mouthrinses. Four databases were searched for systematic reviews related to chlorhexidine and dentistry (MEDLINE, Embase, Web of Science, and Scopus). Original papers available in the identified studies and meta-analyses were individually screened for allergy by both authors. An initial 804 studies were identified, of which 46 systematic reviews and the original papers described therein were ultimately analyzed. Only two reviews explicitly addressed the topic of allergy. In a total of 194 original studies and a total of 9,698 patients, no allergies were reported. In 44 control studies, the topic was touched upon, but only in connection with the inclusion and exclusion criteria and possible contraindications. The topic of "allergy" regarding chlorhexidine application as a mouth rinse in dentistry seems to be omnipresent. Nevertheless, true allergies to chlorhexidine in dentistry appear to be low to nonexistent. Precautions, however, should still be taken in practice and further studies should be envisaged, especially in patients with an alleged history of chlorhexidine contact allergy. (Quintessence Int 2022;53:808-814; doi: 10.3290/j.qi.b2841913 based on an original publication (in German) in Parodontologie 2022;33(1):59-69).