Chlorhexidine anaphylaxis in three children secondary to oral exposure without evidence of mucosal breach

Allergic contact dermatitis to chlorhexidine in children

BACKGROUND

Hypersensitivity to chlorhexidine is rare in children. The usefulness of different diagnostic tests for allergic contact dermatitis (ACD) is unknown.

OBJECTIVE

We aim to describe a case series of children with hypersensitivity to chlorhexidine and to compare the results of different diagnostic tests.

PATIENTS

Nine children with hypersensitivity to chlorhexidine were included. Only six of these children and their parents consented to a comprehensive allergy assessment, which included the prick test, intradermal test, patch test, and repeated open application test (ROAT).

RESULTS

Seven children (78%) presented symptoms of chlorhexidine hypersensitivity within the first 5 years of life; two of them before the age of 1 year. In four children, the dermatitis lesions were suggestive of wound superinfection. All six children who participated in the comprehensive diagnostic evaluation had negative results on the prick test. The immediate-reading intradermal test was positive in one case and uncertain in two cases. The patch test was positive in five cases, and the ROAT was positive in all six cases when using 2% chlorhexidine alcohol solution.

CONCLUSION

ACD to chlorhexidine in children appears to be rare and can be difficult to detect. Clinicians should consider this diagnosis when wounds worsen with chlorhexidine. Although the patch test is the most standardized method for detecting ACD, the ROAT with 2% chlorhexidine alcohol solution was the most sensitive test in our patients.

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

New Insights Regarding the Use of Relevant Synthetic Compounds in Dentistry

Worldwide, synthetic compounds are used for both in-office and at-home dental care. They are a valuable resource for both prophylactic and curative treatments for various dental problems, such as tooth decay, periodontal diseases, and many more. They are typically preferred due to their broad range of actions and ability to produce targeted, rapid, and long-lasting effects. Using a 0.12% chlorhexidine mouthwash is capable of reducing the plaque index from 47.69% to 2.37% and the bleeding index from 32.93% to 6.28% after just 2 weeks. Mouthwash with 0.1% OCT is also highly effective, as it significantly lowered the median plaque index and salivary bacterial counts in 152 patients in 5 days compared to a control group (p < 0.0001), while also reducing the gingival index (p < 0.001). When povidone-iodine was used as an irrigant during the surgical removal of mandibular third molars in 105 patients, it resulted in notably lower pain scores after 2 days compared to a control group (4.57 ± 0.60 vs. 5.71 ± 0.45). Sodium hypochlorite is excellent for root canal disinfection, as irrigating with 1% NaOCl completely eliminated the bacteria from canals in 65% patients. A 0.05% CPC mouthwash proved effective for perioperative patient care, significantly decreasing gingival bleeding (p < 0.001) and suppressing Streptococcus levels even one week post-surgery. Lastly, a 6% H2O2 paint-on varnish and 6% H2O2 tray formulations successfully bleached the teeth of 40 patients, maintaining a noticeably whiter appearance up to the 6-month follow-up, with significant color differences from the baseline (p < 0.005). Synthetic compounds have a large research base, which also provides a greater awareness of their mechanism of action and potential adverse effects. For a better understanding of how they work, several methods and assays are performed. These are protocolary techniques through which a compound's efficacy and toxicity are established.

Dual nanocarrier of chlorhexidine and fluconazole: Physicochemical characterization and effects on microcosm biofilms and oral keratinocytes

OBJECTIVES

This study assembled and characterized a dual nanocarrier of chlorhexidine (CHX) and fluconazole (FLZ), and evaluated its antibiofilm and cytotoxic effects.

METHODS

CHX and FLZ were added to iron oxide nanoparticles (IONPs) previously coated by chitosan (CS) and characterized by physical-chemical analyses. Biofilms from human saliva supplemented with Candida species were grown (72 h) on glass discs and treated (24 h) with IONPs-CS carrying CHX (at 39, 78, or 156 µg/mL) and FLZ (at 156, 312, or 624 µg/mL) in three growing associations. IONPs and CS alone, and 156 µg/mL CHX + 624 µg/mL FLZ (CHX156-FLZ624) were tested as controls. Next, microbiological analyses were performed. The viability of human oral keratinocytes (NOKsi lineage) was also determined (MTT reduction assay). Data were submitted to ANOVA or Kruskal-Wallis, followed by Fisher's LSD or Tukey's tests (α=0.05).

RESULTS

Nanocarriers with spherical-like shape and diameter around 6 nm were assembled, without compromising the crystalline property and stability of IONPs. Nanocarrier at the highest concentrations was the most effective in reducing colony-forming units of Streptococcus mutans, Lactobacillus spp., Candida albicans, and Candida glabrata. The other carriers and CHX156-FLZ624 showed similar antibiofilm effects, and significantly reduced lactic acid production (p<0.001). Also, a dose-dependent cytotoxic effect against oral keratinocytes was observed for the dual nanocarrier. IONPs-CS-CHX-FLZ and CHX-FLZ significantly reduced keratinocyte viability at CHX and FLZ concentrations ≥7.8 and 31.25 µg/mL, respectively (p<0.05).

CONCLUSION

The nanotherapy developed outperformed the effect of the combination CHX-FLZ on microcosm biofilms, without increasing the cytotoxic effect of the antimicrobials administered.

CLINICAL SIGNIFICANCE

The dual nanocarrier is a promising topically-applied therapy for the management of oral candidiasis considering that its higher antibiofilm effects allow the use of lower concentrations of antimicrobials than those found in commercial products.