Immediate allergies to chlorhexidine: A series of pediatric cases from the French pharmacovigilance database

Background

Immediate allergic reactions to chlorhexidine have been clearly identified in numerous countries, generating governmental warnings worldwide.

Objectives

The aim of our study was to characterize (i) these allergies, which are less reported in pediatric populations, and (ii) the patient-at-risk profile so as to suggest preventive measures.

Methods

In association with the allergy department and the regional pharmacovigilance center in Rennes University Hospital, France, a multicenter retrospective, descriptive, and observational study was conducted using data from the national pharmacovigilance database for the period of January 1, 2010 to June 30, 2020. Immediate allergies to chlorhexidine cases based on a clinical history compatible with an immunoglobulin E (IgE)-mediated reaction, along with positive allergic testing, were analyzed.

Results

Of the 478 cases identified, 17 pediatric cases of immediate allergic reaction to chlorhexidine (13 cases of grades II–IV anaphylaxis) were retained for the analysis. For 58.8 % of these cases, a history of a previous more moderate reaction to the substance was identified. The reactions occurred most frequently in cases of domestic misuse (88.2 %, n = 15/17) of chlorhexidine to dress a wound. Recurrence was reported for two cases, later leading to severe reactions at each new exposure to the allergen, suggesting an aggravation mechanism.

Conclusion

The number of pediatric cases of immediate allergies to chlorhexidine has possibly been underestimated on account of insufficient knowledge of the allergy and in view of its common usage. Information on the method of caring for wounds among children and on the risk of allergic sensitization as well as exploring any unusual reaction to chlorhexidine application could reduce the number of allergic reactions.