Immediate hypersensitivity to chlorhexidine

Allergic contact dermatitis to chlorhexidine-containing antiseptics and their excipients in children: A series of six cases

Contact allergy to skin disinfectants is not often recognized in children. We report the cases of six children (1-16.5 years old) with allergic contact dermatitis to ingredients commonly contained in commercial antiseptic and cosmetic products. Patch test responses to chlorhexidine, benzyl alcohol, and benzalkonium chloride varied from one child to another one, but most children were sensitized to at least two components. In several of the cases, exposure had initially occurred in the neonatal period, but diagnosis occurred only after multiple reactions of increasing severity.

Review of allergic reactions from use of chlorhexidine on medical products in clinical settings over 40 years: Risks and mitigations

Chlorhexidine is an antimicrobial agent widely used for infection prevention in medical settings. Nevertheless, allergic reactions ranging from mild to severe have been reported following its use. In this review, we analyzed all case reports published between the introduction of chlorhexidine and the end of 2019 for allergic responses associated with the use of medical devices and or other medical products containing chlorhexidine (CHX) to ascertain the prevalence of severe CHX allergic reactions and what practices might best mitigate those risks.In total, 77 publications containing 124 reported cases of allergic reactions were grouped into 3 product categories, catheters, semisolids, and fluid products. The country, type of reaction, route of sensitization, allergy confirmation, and intervention or mitigation was extracted for each case. Overall, 30 cases were associated with catheters, 46 cases were associated with semisolid products, and 48 cases were associated with the use of other medical products. Severe cases were managed with intravenous fluids, steroids, and epinephrine (adrenaline). None of the reported cases were fatal. The allergy risks can be mitigated by better warning and training clinicians and by recording and screening patient histories for CHX presensitization from prior exposure. For patients undergoing pre-use blood tests, IgE antibody screens can also be performed. Finally, as a precaution in the event a rare severe allergic reaction occurs, procedure carts and rooms can be prestocked with injectable epinephrine and other rapidly acting anti-inflammatory medications.

Chlorhexidine gluconate does not result in epidermal microbiota dysbiosis in healthy adults

BACKGROUND

Chlorhexidine gluconate (CHG) and other skin antiseptics are ubiquitous in healthcare settings and are routinely used to bathe patients' skin. The commensal epidermal microbiota is believed to provide colonization resistance and other benefits to the host; yet little is known regarding the long-term stability of the epidermal microbiota, and the impact of CHG bathing. We aimed to assess the influence of CHG exposure to the epidermal microbiota and evaluate the long-term stability of the epidermal microbiota.

METHODS

The epidermal microbiota of 5 individuals was sampled using thorough swabbing of the calf, and characterized via 16S rRNA amplicon sequencing, prior to CHG bathing, and then at 30 minutes, 3 hours, 1 day, 3 days, and 7 days postbathing. Roughly 4 months later, samples were collected from the same 5 individuals, using an identical timeline but with no CHG exposure.

RESULTS

The epidermal microbiota showed no greater change 30 minutes postexposure to CHG, than was observed in the same individuals during the recovery period, likely representing the normal sample-to-sample variability. Despite that variability, the epidermal microbiota evinced a remarkable degree of intrasubject stability, even over extended periods of time.

CONCLUSION

We conclude that single applications of CHG cause minimal, if any, disruption of the epidermal microbiota, and that long-term effects of single applications of CHG on the epidermal microbiota are unlikely.

Consensus statement of the Italian society of pediatric allergy and immunology for the pragmatic management of children and adolescents with allergic or immunological diseases during the COVID-19 pandemic

The COVID-19 pandemic has surprised the entire population. The world has had to face an unprecedented pandemic. Only, Spanish flu had similar disastrous consequences. As a result, drastic measures (lockdown) have been adopted worldwide. Healthcare service has been overwhelmed by the extraordinary influx of patients, often requiring high intensity of care. Mortality has been associated with severe comorbidities, including chronic diseases. Patients with frailty were, therefore, the victim of the SARS-COV-2 infection. Allergy and asthma are the most prevalent chronic disorders in children and adolescents, so they need careful attention and, if necessary, an adaptation of their regular treatment plans. Fortunately, at present, young people are less suffering from COVID-19, both as incidence and severity. However, any age, including infancy, could be affected by the pandemic.Based on this background, the Italian Society of Pediatric Allergy and Immunology has felt it necessary to provide a Consensus Statement. This expert panel consensus document offers a rationale to help guide decision-making in the management of children and adolescents with allergic or immunologic diseases.

Anaphylaxis related to disinfection with chlorhexidine in a teenager treated for cancer

INTRODUCTION

Literature shows upcoming allergy to chlorhexidine due to the widespread use of the disinfectant within and outside surgical settings. Only a few case reports have been published regarding the use of topical chlorhexidine disinfectant outside surgery and only a minority of these within the pediatric population.

CASE REPORT

We present a case-report of a teenager, treated for acute lymphoblastic leukemia who developed an anaphylactic shock after repeated chlorhexidine use for skin disinfection at the insertion of a central venous catheter during his chemotherapy treatment. Preceding minor symptoms such as local swelling and pruritus were not recognized as possible allergy to chlorhexidine.Management and outcome: He was treated with two doses of intramuscular adrenaline and transferred to the pediatric intensive care unit where he fully recovered. Specific IgE testing was positive for chlorhexidine. A total avoidance of chlorhexidine was instructed.

DISCUSSION

A similar case was published regarding an anaphylaxis after use of chlorhexidine disinfectant for a dialysis catheter. Almost all other case reports of anaphylactic shock were found within surgical settings or after insertion of an impregnated central venous catheter/urine catheter. We suggest that some of the disinfectant might have been flushed in the catheter and then caused an anaphylactic reaction. The link between symptoms and chlorhexidine was not made until an anaphylactic reaction occurred. Literature data show that chlorhexidine often causes mild preceding symptoms before an anaphylaxis occurs. So let awareness arise around this 'hidden allergen' of which warning reactions often are being missed.

Antimicrobial peptide GH12 as root canal irrigant inhibits biofilm and virulence of Enterococcus faecalis

AIM

The objectives of this laboratory-based study were to investigate the effects of GH12 on Enterococcus faecalis biofilm and virulence.

METHODOLOGY

Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of GH12 against E. faecalis were first determined. A time-kill assay was further conducted. The effects of GH12 on the expression of virulence and stress genes in E. faecalis were evaluated by RT-qPCR. Crystal violet stain was used to investigate the effects of GH12 on E. faecalis biofilm formation and 1-day-old biofilm. Finally, an ex vivo tooth model contaminated with E. faecalis was used to evaluate the antimicrobial activity of GH12 as an irrigant by CFU counting, SEM and CLSM. One-way anova and Tukey's multiple comparisons test were used to compare the differences amongst groups (α = 0.05).

RESULTS

The MICs and MBCs of GH12 against E. faecalis were 8.0 ± 0.0 and 16.0 ± 0.0 mg L^-1 , respectively, and GH12 at 32.0 mg L^-1 reduced the bacterial numbers by more than 99.9% within 1 min. Various virulence genes (efaA, esp and gelE) and stress genes (dnaK, groEL, ctsR and clpPBCEX) in E. faecalis were significantly downregulated by GH12 at sub-MIC levels (P < 0.05). Additionally, both E. faecalis biofilm formation and the biomass of 1-day-old E. faecalis biofilm were significantly reduced by GH12 (P < 0.05). Elimination of E. faecalis in biofilms from root canal walls was achieved through irrigation with 64.0 mg L^-1 GH12 for 30 min. CLSM analysis revealed that GH12 at 64.0 mg L^-1 was most effective in eliminating bacteria within dentinal tubules (P < 0.05).

CONCLUSION

In a laboratory setting, and when used as an irrigant, GH12 suppressed E. faecalis, downregulated specific virulence and stress-associated genes, eliminated intracanal E. faecalis protected by biofilms and killed bacteria in dentinal tubules. These results emphasize the need for preclinical and clinical studies to explore the potential of GH12 as an antimicrobial agent during root canal treatment.

Health care worker sensitivity to chlorhexidine-based hand hygiene solutions: A cross-sectional survey

BACKGROUND

Health service hand hygiene programs have seen widespread use of chlorhexidine solutions. Reports of both immediate and delayed hypersensitivity to chlorhexidine are increasing among health care workers. This study examined the prevalence of self-reported symptoms of sensitivity to chlorhexidine solutions among health care workers.

METHODS

This study was a cross-sectional online anonymous survey of all workers at a single health service.

RESULTS

Of the 1,050 completed responses, 76.3% were female, 35.3% were nurses and midwives, 28% were medical staff, and 8.7% were working in nonclinical areas. Over 95% used chlorhexidine-based hand hygiene products in their workplace. Nurses and midwives most frequently reported asthma (13.7%), contact dermatitis (27.8%), and previous testing for allergy to chlorhexidine (4.9%). There was a correlation between both the presence of atopy, eczema, or dermatitis and the self-reporting of dry skin, eczema, or dermatitis attributed to chlorhexidine use.

DISCUSSION

Occupational chlorhexidine allergy is an important risk to health care workers. Self-reported symptoms of sensitivity to chlorhexidine solutions revealed high reported use and presence of skin symptoms among health care workers.

CONCLUSIONS

Screening programs need to identify nurses who develop chlorhexidine sensitivity due to occupational exposure. Strategies to mitigate risk should provide alternatives for those with sensitization.

Allergic contact dermatitis to chlorhexidine in pediatric patients

Chlorhexidine is one of the most widely used antiseptics in our environment. Allergic contact dermatitis to chlorhexidine is common in adults, but is quite rare in the pediatric population. Its diagnosis is important because it can mimic other dermatoses common during childhood, and it can also lead to acute immediate hypersensitivity reactions following successive exposures.

Chlorhexidine allergy in the perioperative setting: a narrative review

Chlorhexidine is an antiseptic with a broad spectrum of activity and a persistent effect on skin. Consequently, it has become an ubiquitous antiseptic in healthcare and the community. As use has become widespread, increasing numbers of cases of allergy have been reported in the literature, including cases of anaphylaxis to chlorhexidine gels used on mucous membranes, chlorhexidine-impregnated devices such as central venous catheters, chlorhexidine preparations used on wounds and broken skin, and cases after dental procedures. Numerous governmental warnings have been issued over recent decades to warn of the risk of allergy to chlorhexidine on mucosal surfaces or in medical devices. Whilst the number of published cases likely underestimates the true prevalence of reactions, we retrospectively surveyed clinics with experience in investigating perioperative chlorhexidine allergy. Despite differences in investigation practice before the survey took place, 13 clinics responded which together had diagnosed 252 cases of anaphylaxis to chlorhexidine, and cases of delayed allergy. In eight of 13 clinics, chlorhexidine was within the top four most commonly diagnosed causes of perioperative anaphylaxis. Despite this, the incidence of anaphylaxis to chlorhexidine is low given that patients are very commonly exposed. Sensitisation of healthcare workers can occur, but is uncommon. Before exposing patients to this antiseptic, consideration of the potential risk vs benefit should be undertaken, particularly for higher risk exposures, such as mucosal exposure or i.v. exposure via impregnated lines. Difficulties exist in protecting patients with known allergies from re-exposure to chlorhexidine, which would be improved with uniform labelling and chlorhexidine product registers.

Chlorhexidine Allergy: On the Rise and Often Overlooked

PURPOSE OF REVIEW

In recent years, the risk of allergy to chlorhexidine is increasingly recognised. In this review, we discuss why the allergy is so easily overlooked and point out several preventative initiatives that can minimise the risk of both chlorhexidine sensitisation and allergy development and accidental re-exposure in patients with chlorhexidine allergy. Testing for chlorhexidine allergy is also discussed.

RECENT FINDINGS

Numerous reports have been published from many different specialties. Symptoms range from mild skin symptoms to life-threatening anaphylaxis. Testing for chlorhexidine allergy is based on skin testing and in vitro testing. Recently, it was found that both skin prick testing and specific IgE have high sensitivities and specificities. This review gives an overview of chlorhexidine allergy with a special focus on preventative initiatives and testing.

The synthetic human beta-defensin-3 C15 peptide exhibits antimicrobial activity against Streptococcus mutans, both alone and in combination with dental disinfectants

Streptococcus mutans is a major etiologic agent of human dental caries that forms biofilms on hard tissues in the human oral cavity, such as tooth and dentinal surfaces. Human β-defensin-3 (HBD3) is a 45-amino-acid natural antimicrobial peptide that has broad spectrum antimicrobial activity against bacteria and fungi. A synthetic peptide consisting of the C-terminal 15 amino acids of HBD3 (HBD3-C15) was recently shown to be sufficient for its antimicrobial activity. Thus, clinical applications of this peptide have garnered attention. In this study, we investigated whether HBD3-C15 inhibits the growth of the representative cariogenic pathogen Streptococcus mutans and its biofilm formation. HBD3-C15 inhibited bacterial growth, exhibited bactericidal activity, and attenuated bacterial biofilm formation in a dose-dependent manner. HBD3-C15 potentiated the bactericidal and anti-biofilm activity of calcium hydroxide (CH) and chlorhexidine digluconate (CHX), which are representative disinfectants used in dental clinics, against S. mutans. Moreover, HBD3-C15 showed antimicrobial activity by inhibiting biofilm formation by S. mutans and other dentinophilic bacteria such as Enterococcus faecalis and Streptococcus gordonii, which are associated with dental caries and endodontic infection, on human dentin slices. These effects were observed for HBD3-C15 alone and for HBD3-C15 in combination with CH or CHX. Therefore, we suggest that HBD3-C15 is a potential alternative or additive disinfectant that can be used for the treatment of oral infectious diseases, including dental caries and endodontic infections.