Chlorhexidine – a commonly used but often neglected culprit of dialysis associated anaphylactic reactions (case report)

BACKGROUND: Hemodialysis-associated anaphylactic reactions are rare and frequently complex in nature due to the sheer number of possible culprit agents. Unfortunately, dialysis is often unavoidable or strictly essential for life-saving solute clearance or fluid removal in patients with end stage kidney failure and those with severe acute kidney injury. It is of utmost importance that the culprit agent is identified and avoided to allow continuation of dialysis treatment as needed. CASE PRESENTATION: We present 2 cases of hemodialysis-associated anaphylactic reactions. These patients developed anaphylactic reactions peri-dialysis and were initially suspected to have dialyser reactions. They were investigated in a controlled healthcare setting and possible culprit agents were systemically identified and eliminated. They both underwent allergy testing and were diagnosed with chlorhexidine allergy. Of note, Case 1 was an incident dialysis patient at the time of presentation and Case 2 was a prevalent dialysis patient. This suggests that the time from initial sensitization to reaction may not always be helpful in determining if a particular agent is the culprit of an anaphylactic reaction. In both cases, the patients were dialysed through a tunnelled dialysis catheter. We postulate that the presence of an exit site, which represents a compromise to the integrity of the skin’s epidermal barrier, may have a significant role in the development of these reactions. As chlorhexidine is a widely used disinfectant in hemodialysis, it is imperative that we consider it as a possible culprit agent when these reactions arise. To our knowledge, there are no other reported cases of anaphylaxis secondary to chlorhexidine use in dialysis patients other than a previous report in 2017. Our report also highlights the possibility of these reactions occurring more frequently in patients with damaged epidermal barriers and in patients exposed to higher environmental concentrations of chlorhexidine. These are novel concepts that can be explored with further research. CONCLUSION: Chlorhexidine associated anaphylactic reactions can occur in the peri-dialysis setting and a high index of suspicion is paramount to diagnosis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12882-021-02646-x.