Anaphylaxis to chlorhexidine. Case report. Implication of immunoglobulin E antibodies and identification of an allergenic determinant

Life-threatening chlorhexidine anaphylaxis caused by skin preparation before chlorhexidine-free central venous catheter insertion: a case report and literature review

Chlorhexidine is a common cause of perioperative anaphylaxis, and global regulatory authorities have issued warnings about anaphylaxis due to chlorhexidine-containing central venous catheters (CVC) and its mucosal absorption. We present a case of life-threatening anaphylaxis after CVC insertion caused by chlorhexidine used for skin preparation. The onset of anaphylaxis was rapid and very severe, resulting in pulseless electrical activity. The patient was successfully resuscitated by emergency veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Our case suggests that even skin preparation before chlorhexidine-free CVC insertion can cause life-threatening anaphylaxis. We reviewed the literature on chlorhexidine anaphylaxis cases and categorized all potential routes of chlorhexidine exposure to assess the risk following skin preparation. Our results showed that skin preparation before CVC insertion was the third most common cause of chlorhexidine anaphylaxis after transurethral exposure and chlorhexidine-containing CVCs. However, skin preparation with chlorhexidine before CVC insertion was sometimes overlooked as a cause of chlorhexidine anaphylaxis, and its risk might be underestimated. Further, no previous reports have described life-threatening anaphylaxis solely due to chlorhexidine skin preparation before CVC insertion. CVC insertion might cause the chlorhexidine used for skin preparation to reach the vascular system and should be recognized as a potential cause of life-threatening chlorhexidine anaphylaxis.

Allergic and other adverse reactions to drugs used in anesthesia and surgery

The list of drugs patients may be exposed to during the perioperative and postoperative periods is potentially extensive. It includes induction agents, neuromuscular blocking drugs (NMBDs), opioids, antibiotics, sugammadex, colloids, local anesthetics, polypeptides, antifibrinolytic agents, heparin and related anticoagulants, blue dyes, chlorhexidine, and a range of other agents depending on several factors related to individual patients’ clinical condition and progress in the postoperative recovery period. To avoid poor or ultrarapid metabolizers to a particular drug (for example tramadol and codeine) or possible adverse drug reactions (ADRs), some drugs may need to be avoided during or after surgery. This will be the case for patients with a history of anaphylaxis or other adverse events/intolerances to a known drug. Other drugs may be ceased for a period before surgery, e.g., anticoagulants that increase the chance of bleeding; diuretics for patients with acute renal failure; antihypertensives relative to kidney injury after major vascular surgery; and serotonergic drugs that together with some opioids may rarely induce serotonin toxicity. Studies of germline variations shown by genotyping and phenotyping to identify a predisposition of genetic factors to ADRs offer an increasingly important approach to individualize drug therapy. Studies of associations of human leukocyte antigen (HLA) genes with some serious delayed immune-mediated reactions are ongoing and variations of drug-metabolizing cytochrome CYP450 enzymes, P-glycoprotein, and catechol-O -methyltransferase show promise for the assessment of ADRs and non-responses to drugs, particularly opioids and other analgesics. Surveys of ADRs from an increasing number of institutions often cover small numbers of patients, are retrospective in nature, fail to clearly identify culprit drugs, and do not adequately distinguish immune-mediated from non-immune-mediated anaphylactoid reactions. From the many surveys undertaken, the large list of agents identified during and after anesthesia and surgery are examined for their ADR involvement. Drugs are classified into those most often involved, (NMBD and antibiotics); drugs that are becoming more frequently implicated, namely antibiotics (particularly teicoplanin), and blue dyes; those becoming less frequently involved; and drugs more rarely involved in perioperative, and postoperative adverse reactions but still important and necessary to keep in mind for the occasional potential sensitive patient. Clinicians should be aware of the similarities between drug-induced true allergic type I IgE/FcεRI- and pseudoallergic MRGPRX2-mediated ADRs, the clinical features of each, and their distinguishing characteristics. Procedures for identifying MRGPRX2 agonists and diagnosing and distinguishing pseudoallergic from allergic reaction mechanisms are discussed.

Mast cell activation test: A new asset in the investigation of the chlorhexidine cross-sensitization profile

BACKGROUND

Insights into the IgE cross-sensitization and possible cross-reactivity patterns of sera reactive to chlorhexidine (CHX) are still incomplete and are likely to benefit from a functional exploration using a passive mast cell activation test (pMAT). Therefore, we want to study whether the pMAT with CHX-specific IgE (sIgE) enables to depict effector cell degranulation in response to alexidine (ALX), octenidine (OCT) and/or polyhexamethylene biguanide (PHMB) indicative of cross-reactivity between these compounds and CHX.

METHODS

Serum of 10 CHX-allergic patients, nine individuals with an isolated sIgE CHX and five healthy controls were included. Human cultured mast cells (MCs) were, before and after sensitization, challenged with CHX, ALX, OCT or PHMB. Degranulation was measured via quantification of upregulation of CD63.

RESULTS

Mast cell responsiveness to ALX and OCT was demonstrable with 4/10 and 3/10 of the sera of CHX-allergic patients respectively. Percentage of degranulation varied between 12 and 34% for ALX-reactive MCs and between 4 and 22% for OCT-reactive MCs. No reactivity to ALX or OCT was demonstrable when using sera obtained from individuals with an isolated sIgE CHX or from healthy controls. Unlike CHX, ALX and OCT, PHMB turned out to be a direct MC activator via occupation of MRGPRX2. PHMB-reactive sIgEs were demonstrable in some patients with an isolated sIgE CHX but were unable to trigger PHMB-induced degranulation in MRGPRX2 knockdown MCs.

CONCLUSION

Mast cells constitute an attractive tool to explore cross-reactivity between structurally similar compounds. Along with the identification of safe alternatives for the individual patient, the pMAT can advance our insights into sIgE cross-reactivity patterns including assessment of molecules not yet approved for human use.

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.

IgE-mediated chlorhexidine allergy-Cross-reactivity with other biguanide disinfectants

BACKGROUND

Chlorhexidine (CHX) is a widely utilized disinfectant that can cause IgE-mediated urticaria/anaphylaxis. The cross-reactivity of patients with IgE-mediated CHX allergy with other disinfectants, which share structural similarities with CHX like polyhexanide (polyhexamethylene biguanide; PHMB), alexidine (ALX), or octenidine (OCT), is unknown.

METHODS

Forty-four patients with anaphylaxis or urticaria upon CHX exposure and positive skin prick test (SPT) and/or positive CHX ImmunoCAP test (Phadia TFS, Uppsala, Sweden) were recruited. IgE to the biguanide and/or hexamethylene structure was investigated with PHMB ImmunoCAP (n = 32) and by basophil activation tests (BAT) with CHX and ALX (n = 37). Inhibition tests of CHX and PHMB ImmunoCAPs by CHX, ALX, PHMB, and OCT were performed.

RESULTS

IgE reactivity to PHMB as surrogate marker for biguanide/hexamethylene reactivity was detected in 5/32 sera. Seven of 37 patients showed a positive BAT with ALX, but only under optimized conditions. Binding to CHX ImmunoCAP was inhibited by ALX in 1/32 sera, and binding to PHMB was blocked by ALX (1/5) and by OCT in another (1/5). In SPT, 9/10 patients were positive for CHX and 3 of them with ALX (only at highest concentration at 5 mg/mL). A further patient reacted primarily with OCT and showed IgE cross-reactivity with CHX, ALX, and PHMB.

CONCLUSION

The IgE response to CHX seems polyclonal. The chloroguanide ending of CHX is the main epitope for the IgE and is suitable as screening assay to detect CHX reactivity. IgE-reactivities with the biguanide or hexamethylene components of other disinfectants (ALX, PHMB) can be detected by SPT, PHMB ImmunoCAP, and ALX-BAT in 15%-33% of CHX-allergic patients.

Chlorhexidine wipes: Time to stop and think about allergy

Summary

We report three precautionary cases of perioperative anaphylaxis to chlorhexidine isopropyl alcohol antiseptic wipes (CAW). In two cases, the patients were inadvertently re-exposed to CAW despite known chlorhexidine hypersensitivity. Chlorhexidine has been described as ‘the hidden allergen’. As a result, patients may suffer multiple reactions before chlorhexidine is confirmed as the cause. Healthcare workers may not recognize that products they use for common clinical steps contain chlorhexidine. These cases highlight the need for constant vigilance to facilitate the safe management of patients with a history of chlorhexidine anaphylaxis.

An Unexpected Cause of an Acute Hypersensitivity Reaction during Recovery from Anaesthesia

Acute hypersensitivity reactions to chlorhexidine in the operating room are probably more likely to occur during the early phases of anaesthesia because chlorhexidine is often used for cleaning the surgical field or during placement of indwelling catheters. We report a case of an acute hypersensitivity reaction that occurred in the post anaesthetic care unit. Subsequent skin testing suggested sensitivity to chlorhexidine, which had been applied over the vaginal mucosa at the end of surgery. Relevant issues in the investigation of acute hypersensitivity reactions in the post anaesthetic period are discussed.

Chlorhexidine-related anaphylaxis in urological practice

Introduction:

There have been numerous case reports highlighting the risk of anaphylactic reactions when using chlorhexidine-containing urethral gels. However, there is no evidence that the inclusion of chlorhexidine in urethral gels reduces the risk of catheter associated urinary tract infection.

Methods:

Pubmed and Medline were searched for the keywords anaphylaxis (and) chlorhexidine. Case reports were reviewed and information regarding year, patient demographics, country, chlorhexidine administration route, signs, symptoms encountered and the presence of subsequent allergy testing were analysed.

Results:

In terms of clinical features, 89% (32/36) of patients were noted to have skin changes recorded as either urticaria, flushing, rash, erythema or wheals. Respiratory changes were recorded in 67% (24/36), which included those described as bronchospasm, chest tightness, wheeze or cough. Hypotension was documented in 92% of reports (33/36) while hypoxia was recorded in half of the reports (18/36) and a quarter (8/36) had periorbital angioedema or documented oral or tongue swelling. Only four out of 36 patients required formal cardiopulmonary resuscitation and no patients died.

Conclusion:

Chlorhexidine-related anaphylaxis is a relatively frequently reported entity. Despite this, there appears to be no compelling evidence that chlorhexidine mitigates the risk of catheter-associated urinary tract infection.

Level of evidence:

Level 4 evidence.

Chlorhexidine-induced anaphylaxis in surgical patients: a review of the literature

BACKGROUND

Chlorhexidine (CHL) has antiseptic and disinfectant properties used to prevent hospital-acquired infections. CHL-induced anaphylaxis is poorly reported in surgical literature despite government warnings and growing recognition. The aim of this review is to increase awareness of CHL-induced anaphylaxis in the surgical population.

METHODS

Literature review of Embase, Medline, PubMed and the Cochrane library using 'anaphylaxis (and) chlorhexidine' search terms.

RESULTS

Thirty-six articles were published on surgical patients suffering anaphylaxis to CHL. Within these, seven patients had two proven separate anaphylactic reactions and one had three separate proven anaphylactic reactions. The most commonly affected speciality was urology. The majority occurred during elective procedures. A history of atopy was surprisingly uncommon as was bronchospasm. Six patients required active chest compressions and 39.71% of patients had their surgical procedure abandoned. Unplanned intensive care admissions occurred in 27.94%.

DISCUSSION

In order to reduce abandoned procedures, unplanned intensive care unit admissions, morbidity and mortality associated with CHL-induced anaphylaxis we recommend the following: rationalization of CHL-containing products, greater vigilance regarding subtle symptoms of CHL allergy, appropriate investigation of these symptoms and a greater awareness of CHL-containing products. Lastly, we outline the appropriate investigations and highlight the need for meticulous documentation in those who are CHL allergic.

Perioperative chlorhexidine allergy: Is it serious?

Chlorhexidine is an antiseptic agent, commonly used, in many different preparations, and for multiple purposes. Despite its superior antimicrobial properties, chlorhexidine is a potentially allergenic substance. The following is a review of the current evidence-based knowledge of allergic reactions to chlorhexidine associated with surgical and interventional procedures.

Anaphylaxis during the perioperative period

The incidence of anaphylaxis during anesthesia has been reported to range from 1 in 4000 to 1 in 25,000. Anaphylaxis during anesthesia can present as cardiovascular collapse, airway obstruction, and/or skin manifestation. It can be difficult to differentiate between immune and nonimmune mast cell-mediated reactions and pharmacologic effects from the variety of medications administered during general anesthesia. In addition, cutaneous manifestations of anaphylaxis are less likely to be apparent when anaphylaxis occurs in this setting. The evaluation of IgE-mediated reactions to medications used during anesthesia can include skin testing to a variety of anesthetic agents. Specifically, thiopental allergy has been documented by skin tests. Neuromuscular blocking agents such as succinylcholine can cause nonimmunologic histamine release, but there have also been reports of IgE-mediated reactions in some patients. Reactions to opioid analgesics are usually caused by direct mast cell mediator release rather than IgE-dependent mechanisms. Antibiotics that are administered perioperatively can cause immunologic or nonimmunologic reactions. Protamine can cause severe systemic reactions through IgE-mediated or nonimmunologic mechanisms. Blood transfusions can elicit a variety of systemic reactions, some of which might be IgE-mediated or mediated through other immunologic mechanisms. The management of anaphylactic reactions that occur during general anesthesia is similar to the management of anaphylaxis in other situations.

Vaginal chlorhexidine during labour to prevent early-onset neonatal group B streptococcal infection

BACKGROUND

Although early-onset group B β-hemolytic streptococcus (GBS) infection is rare, it accounts for approximately 30% of neonatal infections, has a high mortality rate, and is acquired through vertical transmission from colonized mothers. Several trials have demonstrated the efficacy of intrapartum antibiotic prophylaxis (IAP) for preventing early-onset disease (EOD). Vaginal disinfection with chlorhexidine during labour has been proposed as another strategy for preventing GBS EOD in the preterm and term neonate. Chlorhexidine has been found to have no impact on antibiotic resistance, is inexpensive, and applicable to poorly equipped delivery sites.

OBJECTIVES

To determine the effectiveness of vaginal disinfection with chlorhexidine during labour in women who are colonized with GBS for preventing early-onset GBS infection in preterm and term neonates.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 October 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized and quasi-randomized trials comparing vaginal disinfection with chlorhexidine (vaginal wash or gel/cream) versus placebo, or no treatment.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed the trials for inclusion and risk of bias, extracted the data and checked them for accuracy.

MAIN RESULTS

We identified no new trials eligible for inclusion in this update. One study was moved from included to excluded studies from the previous version of the review. Four studies, including 1125 preterm and term infants, met the inclusion criteria and reported on at least one of the outcomes of interest. For the comparison chlorhexidine (vaginal wash or gel) versus placebo or no treatment, two studies (n = 987) were pooled. There was no statistically significant difference in early-onset GBS disease (sepsis and/or meningitis) comparing chlorhexidine (vaginal wash or gel/cream) versus placebo or no treatment; risk ratio (RR), 2.32 (95% confidence interval (CI) 0.34 to 15.63); I-squared (I²) = 0% or in GBS pneumonia; RR 0.35 (95% CI 0.01 to 8.6); test for heterogeneity not applicable. The outcome of colonization of the neonate with GBS was reported in three studies (n = 328); RR 0.64 (95% CI 0.40 to 1.01; there was substantial between-study heterogeneity (Chi² = 3.19; P = 0.20; I² = 37%). Maternal mild side effects (stinging or local irritation) (three trials, 1066 women) were more commonly seen in women treated with chlorhexidine (RR 8.50 (95% CI 1.60 to 45.28); there was no heterogeneity (Chi² = 0.01, df = 1 (P = 0.91); I² = 0%). No side effects were reported among the neonates.For the comparison chlorhexidine vaginal wash verus mechanical washing with placebo or no treatment (one study, n = 79), there was a significant reduction in neonatal colonization with GBS; RR 0.32 (95% CI 0.12 to 0.90). Tests for heterogeneity not applicable. There were no other significant results for this comparison.For the comparison chlorhexidine gel or cream versus placebo or no treatment, there were no statistically significant results for the outcomes reported on.The quality of the trials varied and the overall risk of bias was rated as unclear or high. The quality of the evidence using GRADE was very low for the outcomes of the comparison chlorhexidine (vaginal wash or gel/cream) versus placebo or no treatment. These outcomes included: early-onset GBS disease (sepsis and/or meningitis), GBS pneumonia, neonatal colonization with GBS, neonatal mortality due to early-onset GBS infection and adverse (mild) effects in the mother and the neonate.

AUTHORS' CONCLUSIONS

The quality of the four included trials varied as did the risk of bias and the quality of the evidence using GRADE was very low. Vaginal chlorhexidine was not associated with reductions in any of the primary outcomes of early-onset GBS disease (sepsis and/or meningitis) or GBS pneumonia. Vaginal chlorhexidine may reduce GBS colonization of neonates. The intervention was associated with an increased risk of maternal mild adverse effects. The review currently does not support the use of vaginal disinfection with chlorhexidine in labour for preventing early-onset disease. Results should be interpreted with caution as the methodological quality of the studies was poor. As early-onset GBS disease is a rare condition trials with very large sample sizes are needed to assess the effectiveness of vaginal chlorhexidine to reduce its occurrence. In the era of intrapartum antibiotic prophylaxis, such trials may be difficult to justify especially in developed countries.

Chlorhexidine: an unrecognised cause of anaphylaxis

Chlorhexidine is a highly effective antiseptic and disinfectant. In the past 20 years there has been a substantial increase in the number of chlorhexidine containing products used in healthcare. Anaphylaxis to chlorhexidine was first reported in 1984 and was almost always seen in men. However, in the last 4 years we have observed a surge in confirmed cases of anaphylaxis to chlorhexidine, with increasing numbers of female patients recently diagnosed. Yet, awareness of chlorhexidine as a cause of anaphylaxis is low because it is not a drug but a 'hidden' allergen, for example as a coating on medical devices such as central lines and urinary catheters. Patients will often have more than one allergic/anaphylactic reaction before the diagnosis is suspected. We have observed that there is poor recognition of an initial allergic reaction to chlorhexidine, which is well described. This, alongside poor labelling of chlorhexidine containing products, has resulted in further inadvertent exposure resulting in severe anaphylaxis. Prompt referral to a specialist allergy centre ensures appropriate investigations, diagnosis and management. Increasing awareness of the potential risk of life-threatening anaphylaxis associated with chlorhexidine use is vital, particularly in perioperative procedures. Healthcare workers are fundamental in avoiding and preventing further reactions to chlorhexidine containing products in patients diagnosed with anaphylaxis to chlorhexidine.

Standardized testing with chlorhexidine in perioperative allergy--a large single-centre evaluation

BACKGROUND

Perioperative allergic reactions to chlorhexidine are often severe and easily overlooked. Although rare, the prevalence remains unknown. Correct diagnosis is crucial, but no validated provocation model exists, and other diagnostic tests have never been evaluated. The aims were to estimate (i) the prevalence of chlorhexidine allergy in perioperative allergy and (ii) the specificity and sensitivity for diagnostic tests for chlorhexidine allergy.

METHODS

We included all patients investigated for suspected perioperative allergic reactions in the Danish Anaesthesia Allergy Centre during 2004-2012. The following tests were performed: specific IgE (Immunocap® ; Phadia AB, Sweden), histamine release test (HR) (RefLab ApS, Denmark), skin prick test (SPT) and intradermal test (IDT). Positivity criteria were as follows: specific IgE >0.35 kUA/l; HR class 1-12; SPT mean wheal diameter ≥3 mm; IDT mean wheal diameter ≥ twice the diameter of negative control. Chlorhexidine allergy was post hoc defined as a relevant clinical reaction to chlorhexidine combined with two or more positive tests. Based on this definition, sensitivity and specificity were estimated for each test.

RESULTS

In total, 22 of 228 patients (9.6%) met the definition of allergy to chlorhexidine. Estimated sensitivity and specificity were as follows: specific IgE (sensitivity 100% and specificity 97%), HR (sensitivity 55% and specificity 99%), SPT (sensitivity 95% and specificity 97%) and IDT (sensitivity 68% and specificity 100%).

CONCLUSIONS

In patients investigated for suspected perioperative allergic reactions, 9.6% were diagnosed with allergy to chlorhexidine. Using our definition of chlorhexidine allergy, the highest combined estimated sensitivity and specificity was found for specific IgE and SPT.

Work-related respiratory symptoms among health centres cleaners: a cross-sectional study

OBJECTIVES

Several studies, mostly based on questionnaire-derived data, have shown an increased risk of allergic diseases, especially asthma, among cleaners. The risk factors and etiological mechanisms are still being investigated. Occupational exposure to various chemical and biological agents may induce specific sensitization and/or irritant effects. The aim of our study was to estimate the prevalence of work-related symptoms suggesting the presence of allergic disease reported by cleaners, and to relate them to the results of commercially available and standardized objective tests used for screening detection of occupational sensitization and chronic respiratory disorders.

MATERIAL AND METHODS

A cross-sectional study was performed among 142 Polish workers of cleaning service in their workplaces. A detailed questionnaire, skin prick tests to common allergens and chemicals used by these workers for cleaning purposes (chloramine T, chlorhexidine, formaldehyde, glutaraldehyde, benzalconium chloride), total and specific serum IgE antibodies to disinfectants and rest spirometry were performed in all the subjects.

RESULTS

Fifty nine percent of all the subjects declared occurrence of at least 1 symptom suggesting allergic ailment during cleaning activities at work. Skin prick tests and specific serum IgE antibodies to disinfectants were negative in all the subjects. In 8 cases wheezing was detected during auscultation, but only in 5 of them obstructive pattern in rest spirometry was found.

CONCLUSIONS

Occupational allergic causation of symptoms among cleaners could be less likely than work-related symptoms associated with exacerbations of new-onset or pre-existing respiratory diseases. Therefore, in this group of workers, mainly the non-specific irritant impact of chemicals on airways should be taken into consideration.

Immediate hypersensitivity to chlorhexidine is increasingly recognised in the United Kingdom

BACKGROUND

Chlorhexidine is widely used as an antiseptic agent. It is a potentially allergenic substance that can cause severe hypersensitivity reactions.

OBJECTIVE

We describe six patients who had anaphylactic reactions attributed to chlorhexidine during surgery. These patients were exposed to chlorhexidine in gels, swabs and catheters.

MATERIALS AND METHODS

Six patients from three UK centres with clinical history suggestive of anaphylaxis during surgery are reported. Detailed history, review of case notes, determination of chlorhexidine specific IgE, mast cell tryptase and skin tests were performed.

RESULTS

On detailed assessment five of six patients demonstrated a previous history of reactions on re-exposure to chlorhexidine. All six patients had elevated specific IgE to chlorhexidine. Skin prick test with chlorhexidine was performed in four of the six patients and was found to be positive.

CONCLUSION

Immediate hypersensitivity to chlorhexidine appears to be common but underreported in the UK. We recommend that centres investigating patients with reactions during anaesthesia and surgery should routinely include testing for chlorhexidine allergy.

Severe anaphylactic reaction to chlorhexidine during total hip arthroplasty surgery. A case report

Two consecutive hip surgery procedures in the same patient were aborted following a severe anaphylactic reaction of the patient. After the second procedure, the patient was diagnosed to be allergic to chlorhexidine, a component of the gel used to insert a urinary catheter. Chlorhexidine allergy is rare, and the delayed presentation may make it easy to overlook. In hip arthroplasty surgery, this may result in an abandoned procedure and the need for re-operation.

Drug-specific cyclodextrins with emphasis on sugammadex, the neuromuscular blocker rocuronium and perioperative anaphylaxis: implications for drug allergy

Cyclodextrins, oligosaccharides linked in a circular arrangement around a central cavity, are used extensively in the pharmaceutical industry to improve drug delivery. Their usefulness depends on their capacity to form a drug inclusion, or host-guest, complex within the cavity. In an attempt to improve the delivery of the widely used neuromuscular blocking drug (NMBD) rocuronium, a rocuronium inclusion complex was formed with a chemically modified γ-cyclodextrin. The high binding affinity and specificity of the modified carrier (named sugammadex) for rocuronium (and other aminosteroid NMBDs) led to its use in anaesthesia as an innovative and useful agent for rapid reversal of rocuronium-induced neuromuscular block by sequestering the drug as an inclusion complex. This, in turn, led to the suggestion that sugammadex might be useful to remove the NMBD from the circulation of patients experiencing rocuronium-induced anaphylaxis, a suggestion subsequently supported in case reports where traditional treatment had failed. Successful resuscitations suggested that sugammadex might be a valuable new treatment for such intractable cases but, given the inappropriateness of clinical trials, confirmation or refutation will have to await the slow accumulation of results of individual case reports. Important questions related to antibody accessibility of drug allergenic structures on the rocuronium-sugammadex inclusion complex, and the competition between sugammadex and IgE antibodies (both free and cell bound) for rocuronium, also remain and can be investigated in vitro. The sugammadex findings indicate that the use of carrier molecules such as the cyclodextrins to improve drug delivery will sometimes give rise to changed immunologic and allergenic behaviour of some drugs and this will have to be taken into account in preclinical drug safety assessments of drug-carrier complexes. The possibility of encapsulating and removing other allergenic drugs, e.g., penicillins and cephalosporins, in cases of difficult-to-reverse anaphylaxis to these drugs is discussed.

The basophil activation test in immediate-type drug allergy

Diagnosis of drug allergy involves first the recognition of sometimes unusual symptoms as drug allergy and, second, the identification of the eliciting drug. This is an often difficult task, as the clinical picture and underlying pathomechanisms are heterogeneous. In clinical routine, physicians frequently have to rely upon a suggestive history and eventual provocation tests, both having their specific limitations. For this reason both in vivo (skin tests) and in vitro tests are investigated intensively as tools to identify the disease-eliciting drug. One of the tests evaluated in drug allergy is the basophil activation test (BAT). Basophils with their high-affinity IgE receptors are easily accessible and therefore can be used as indicator cells for IgE-mediated reactions. Upon allergen challenge and cross-linking of membrane-bound IgE antibodies (via Fc-epsilon-RI) basophils up-regulate certain activation markers on their surface such as CD63 and CD203c, as well as intracellular markers (eg, phosphorylated p38MAPK). In BAT, these alterations can be detected rapidly on a single-cell basis by multicolor flow cytometry using specific monoclonal antibodies. Combining this technique with in vitro passive sensitization of donor basophils with patients' serum, one can prove the IgE dependence of a drug reaction. This article summarizes the authors' current experience with the BAT in the diagnostic management of immediate-type drug allergy mediated by drug-specific IgE antibodies.

The basophil activation test in immediate drug allergy

Diagnosis of drug allergy is not always straight forward for several reasons. First, a broad spectrum of drugs can elicit various immune-mediated diseases with distinct pathomechanism, secondly, although exact epitope identification is not mandatory for clinical diagnosis, the epitope that causes the reaction is frequently unknown, thirdly in vitro or in vivo test results might not be predictive of a clinical situation, and finally the gold standard or reference test for diagnosis, the drug challenge, is a complicated and sometimes dangerous endeavour. Upon challenge with specific allergens that cross-link membrane-bound IgE antibodies, basophils upregulate the expression of different activation markers such as CD63 and CD203c. These immunophenotypic alterations can be detected on a single-cell basis by multicolour flow cytometry using specific monoclonal antibodies in the basophil activation test (BAT). This review intends to summarise our current experience with the BAT in the diagnostic management of immediate-type allergy to drugs and related compounds that are generally (but not always) mediated by drug-specific IgE antibodies.

Chlorhexidine - Pharmacology and Clinical Applications

chlorhexidine is a widely used skin antisepsis preparation and is an ingredient in toothpaste and mouthwash. It is an especially effective antiseptic when combined with alcohol. Its antimicrobial effects persist because it is binds strongly to proteins in the skin and mucosa, making it an effective antiseptic ingredient for handwashing, skin preparation for surgery and the placement of intravascular access. Catheters impregnated with chlorhexidine and antimicrobial agents can reduce the incidence of catheter-related bloodstream infections. Contact dermatitis related to chlorhexidine is not common in health care workers. The incidence of contact dermatitis to chlorhexidine in atopic patients is approximately 2.5 to 5.4%. Acute hypersensitivity reactions to chlorhexidine are often not recognised and therefore may be underreported. This review discusses the pharmacology, microbiology, clinical applications and adverse effects of chlorhexidine.

IgE-mediated allergy to chlorhexidine

BACKGROUND

Investigations at the Danish Anesthesia Allergy Centre have included testing for allergy to chlorhexidine since 1999.

OBJECTIVE

To investigate whether measurement of IgE and histamine release confirm an IgE-mediated mechanism for chlorhexidine allergy.

METHODS

Twenty-two patients with clinical history suggestive of chlorhexidine allergy were included. Skin tests with chlorhexidine and tryptase measurements were performed during initial investigations. Sera were analyzed retrospectively for IgE and histamine release (passive sensitization) to chlorhexidine.

RESULTS

Twelve patients were skin test positive and 10 were skin test negative. Of the skin test-positive patients, 11 of 12 had IgE to chlorhexidine and 7 of 11 had a positive histamine release test. None of the skin test-negative patients had specific IgE or positive histamine release to chlorhexidine. Skin test-positive patients had higher median age (64 vs 49 y) and were mainly male (11/12 vs 6/10). In both groups, 8 patients had hypotension, but bronchospasm mainly appeared in skin test-negative patients (1/12 vs 6/10). Reactions occurred more often during urologic surgery in skin test-positive patients (5/12 vs 0/10). Baseline tryptase was higher in skin test-positive patients (median, 11.5 vs 3.7 microg/L), and 6 of 7 patients had elevated IgE to chlorhexidine in serum at the time of reaction.

CONCLUSION

This study confirms that chlorhexidine allergy is IgE-mediated and that measurement of specific IgE and histamine release are good adjuncts to skin testing in patients with clinical history suggesting chlorhexidine allergy.

CLINICAL IMPLICATIONS

IgE and histamine release can be used to support the diagnosis of allergy to chlorhexidine.

Anaphylaxis during anaesthesia: diagnostic approach

Correct management of anaphylaxis during anaesthesia requires a multidisciplinary approach with prompt recognition and treatment of the acute event by the attending anaesthesiologist, and subsequent determination of the responsible agent(s) with strict avoidance of subsequent administration of all incriminated and/or cross-reacting compounds. However, correct identification of the causative compound(s) and safe alternatives is not always straightforward and, too often, not done. This review is not intended to discuss acute management of anaesthesia-related anaphylaxis but summarizes the major causes of anaphylaxis during anaesthesia and the diagnostic approach of this rare but potentially life-threatening complication. Apart from general principles about the diagnostic approach, history taking and importance of tryptase quantification, more specific confirmatory diagnostic procedures are organized on the basis of the major causes of perioperative anaphylactic reactions.

Skin reactions related to hand hygiene and selection of hand hygiene products

BACKGROUND

In October 2004, The World Health Organization (WHO) launched the World Alliance for Patient Safety. Within the alliance, the first priority of the Global Patient Safety Challenge is to reduce health care-associated infection. A key action within the challenge is to promote hand hygiene in health care globally as well as at the country level through the campaign "Clean Care is Safer Care." As a result, the WHO is developing Guidelines on Hand Hygiene in Health Care, designed to be applicable throughout the world.

METHODS

This paper summarizes one component of the global WHO guidelines related to the impact of hand hygiene on the skin of health care personnel, including a discussion of types of skin reactions associated with hand hygiene, methods to reduce adverse reactions, and factors to consider when selecting hand hygiene products.

RESULTS

Health care professionals have a higher prevalence of skin irritation than seen in the general population because of the necessity for frequent hand hygiene during patient care.

CONCLUSION

Ways to minimize adverse effects of hand hygiene include selecting less irritating products, using skin moisturizers, and modifying certain hand hygiene practices such as unnecessary washing. Institutions need to consider several factors when selecting hand hygiene products: dermal tolerance and aesthetic preferences of users as well as practical considerations such as convenience, storage, and costs.

Symptoms of immediate chlorhexidine hypersensitivity in patients with a positive prick test

There are numerous reports of anaphylaxis from chlorhexidine in surgical operations and other medical procedures, usually due to its application to wounds or mucous membranes. We wanted to analyse the clinical data of patients with a positive chlorhexidine prick test and perform some additional testing. We studied the case records of the patients with a positive chlorhexidine prick test and performed an open application test and tests for specific IgE. We found 33 patients with a positive prick test. 10 of them had had severe symptoms from chlorhexidine, and 11 had had only mild local symptoms. The size of the prick test reaction was mainly in line with the strength of the severest symptoms. Small 3- to 4-mm reactions were usually without obvious clinical relevance. Specific IgE could be demonstrated in 6 patients out of 14 tested by the ImmunoCAP method. Besides severe attacks, patients with a positive prick test often have milder local symptoms, such as exacerbation of dermatitis. Local symptoms from chlorhexidine-containing products may precede severe attacks. We recommend a prick test to be performed routinely when symptoms during medical interventional procedures, e.g. local and general anaesthesia, are investigated.

Vaginal disinfection for preventing mother-to-child transmission of HIV infection

BACKGROUND

Mother-to-child transmission (MTCT) of HIV infection is one of the most tragic consequences of the HIV epidemic, especially in resource-limited countries, resulting in about 650 000 new paediatric HIV infections each year worldwide. The paediatric HIV epidemic threatens to seriously undermine decade-old child survival programmes.

OBJECTIVES

To estimate the effect of vaginal disinfection on the risk of MTCT of HIV and infant and maternal mortality and morbidity, as well as tolerability of vaginal disinfection in HIV-infected women.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register, Cochrane Pregnancy and Childbirth Register, PubMed, EMBASE, AIDSLINE, LILACS, AIDSTRIALS, and AIDSDRUGS, using standardised methodological filters for identifying trials. We also searched reference lists of identified articles, relevant editorials, expert opinions and letters to journal editors, and abstracts and proceedings of relevant conferences, and contacted subject experts and pharmaceutical companies. There were no language restrictions.

SELECTION CRITERIA

Randomised trials or clinical trials comparing vaginal disinfection during labour with placebo or no treatment, in known HIV-infected pregnant women. Trials had to include an estimate of the effect of vaginal disinfection on MTCT of HIV and or infant and maternal mortality and morbidity.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed trial eligibility and quality, and extracted data. Meta-analysis was performed using the Yusuf-Peto modification of Mantel-Haenszel's fixed effect method.

MAIN RESULTS

Only two trials that included 708 patients met the inclusion criteria. The effect of vaginal disinfection on the risk of MTCT of HIV (OR 0.93, 95% CI 0.65 to 1.33), neonatal death (OR 1.38, 95% CI 0.30 to 6.33), and death after the neonatal period (OR 1.45, 95% CI 0.47 to 4.45) is uncertain. There was no evidence that vaginal disinfection increased adverse effects in mothers (OR 1.15, 95% CI 0.41 to 3.22), and evidence from one trial showed that adverse effects decreased in neonates (OR 0.14, 95% CI 0.07 to 0.31).

AUTHORS' CONCLUSIONS

Currently, there is no evidence of an effect of vaginal disinfection on the risk of MTCT of HIV. Given its simplicity and low cost, there is need for a large well-designed and well-conducted randomised controlled trial to assess the additive effect of vaginal disinfection on the risk of MTCT of HIV in antiretroviral treated women.

Amine Fluoride/Stannous Fluoride and Chlorhexidine Mouthwashes as Adjuncts to Single-Stage Dental Implants: A Comparative Study

BACKGROUND

The growing popularity of non-submerged dental implants in recent years requires a greater emphasis on microbial plaque control. Chlorhexidine (CHX), the most commonly used mouthwash in implant surgery, is sometimes associated with tooth staining and alteration in taste perception. Amine fluoride/stannous fluoride (AmF/SnF2) mouthwash has been shown to have anti-infective properties; however, it has not been tested as an adjunct anti-infective means in non-submerged dental implants. The purpose of this trial was to compare AmF/SnF2 and CHX mouthwashes as adjuncts to single-stage dental implants.

METHODS

Thirty-three patients aged 34 to 79 (mean 54.30 +/- 8.69 SD) requiring dental implants were accepted into the study. Following comprehensive periodontal therapy patients received one to three non-submerged dental implants (maxilla: 17; mandible: 45; anterior: 3, posterior: 59). After surgery patients were given analgesics and antibiotics as well as 2,400 ml of coded mouthwash bottles previously randomized between the two above mentioned formulations. Clinical and radiographic parameters were recorded at baseline and 3 and 12 months post-surgery.

RESULTS

Twelve-month survival rates were 100% and 92.9% for the AmF/SnF2 and CHX groups, respectively. Compliance was slightly higher in the AmF/SnF2 group (84.35% +/- 3.39% versus 78.15% +/- 4.59% SE) but statistically similar. There was no statistically significant difference between the AmF/SnF2 and CHX groups in staining index at 3 months (1.519 +/- 0.22 versus 1.457 +/- 0.24 SE) and patient subjective evaluation of the mouthwashes. Radiographic bone loss was 0.79 +/- 0.23 and 1 +/- 0.13 SE at 3 months and 1.06 +/- 0.13 and 1.27 +/- 0.25 at 12 months for the CHX and AmF/SnF2 groups, respectively; the difference was statistically insignificant (P = 0.388 and 0.504, respectively).

CONCLUSION

Both CHX and AmF/SnF2 mouthwashes can be used post-surgically after one-stage implant surgery.

Anaphylaxis to excipient mannitol: evidence for an immunoglobulin E-mediated mechanism

BACKGROUND

Anaphylaxis to mannitol present naturally in pomegranate and cultivated mushroom in a sensitized subject has been described recently, and an IgE-mediated mechanism to this sugar alcohol has been proposed. The same subject also experienced severe allergic reactions to a chewable pharmaceutical (cisapride drug).

OBJECTIVE

The purpose of the study was to identify allergenic component in the pharmaceutical preparation, and also, to understand the mechanism of immediate hypersensitivity to mannitol.

METHODS

Methodology involved skin prick tests (SPTs), high-performance liquid chromatographic (HPLC) analysis of pharmaceutical preparations, separation of mannitol by Ca++-ion-moderated cation-exchange chromatography, preparation of alditol-protein conjugates by reductive amination, SPT using the conjugates, hapten affinity purification of the allergic serum on D-mannitol-keyhole limpet haemocyanin (KLH)-Sepharose CL-6B, and detection of serum mannitol-specific IgE by ELISA.

RESULTS

Component testing by SPT, and HPLC analysis of various pharmaceuticals indicated that the excipient mannitol is the causative allergen. Mannitol separated from Cisapid MPS showed allergenic activity by SPT. Among the several conjugates tested by SPT, D-mannitol-bovine serum albumin and D-mannitol-KLH showed positive weal/flare reaction, demonstrating the presence of cell-bound mannitol-specific IgE in vivo. Negative results with D-glucitol, D-galactitol, meso-erythritol, and L-mannitol protein conjugates clearly showed that the mannitol-specific human IgE is very specific to the D-isomer of mannitol. ELISA using the hapten affinity-purified allergic serum was positive, demonstrating the presence of mannitol-specific serum IgE in the allergic subject.

CONCLUSION

Mannitol, which is widely used as a food and drug additive (excipient), can rarely cause IgE-mediated anaphylaxis. This study is the first one to demonstrate the presence of mannitol-specific human IgE in a sensitized allergic subject to validate an IgE-mediated hypersensitivity mechanism for mannitol.

Anaphylaxis to an urethral lubricant: chlorhexidine as the "hidden" allergen

We report on a severe allergic reaction during urethral catheterisation, initially erroneously attributed to natural rubber latex (NRL). However, the negative investigations for latex, the uneventful further applications of NRL, the positive skin test and basophil activation test for chlorhexidine strongly support diagnosis of chlorhexidine anaphylaxis. This case illustrates that it is not widely appreciated that "innocent" products such as urethral lubricants may elicit serious life-threatening reactions. Careful inspection of the medical records is once again re-emphasised to be mandatory in order to avert subsequent anaphylaxis.

Epidemiologic background of hand hygiene and evaluation of the most important agents for scrubs and rubs

The etiology of nosocomial infections, the frequency of contaminated hands with the different nosocomial pathogens, and the role of health care workers' hands during outbreaks suggest that a hand hygiene preparation should at least have activity against bacteria, yeasts, and coated viruses. The importance of efficacy in choosing the right hand hygiene product is reflected in the new Centers for Disease Control and Prevention guideline on hand hygiene (J. M. Boyce and D. Pittet, Morb. Mortal. Wkly. Rep. 51:1-45, 2002). The best antimicrobial efficacy can be achieved with ethanol (60 to 85%), isopropanol (60 to 80%), and n-propanol (60 to 80%). The activity is broad and immediate. Ethanol at high concentrations (e.g., 95%) is the most effective treatment against naked viruses, whereas n-propanol seems to be more effective against the resident bacterial flora. The combination of alcohols may have a synergistic effect. The antimicrobial efficacy of chlorhexidine (2 to 4%) and triclosan (1 to 2%) is both lower and slower. Additionally, both agents have a risk of bacterial resistance, which is higher for chlorhexidine than triclosan. Their activity is often supported by the mechanical removal of pathogens during hand washing. Taking the antimicrobial efficacy and the mechanical removal together, they are still less effective than the alcohols. Plain soap and water has the lowest efficacy of all. In the new Centers for Disease Control and Prevention guideline, promotion of alcohol-based hand rubs containing various emollients instead of irritating soaps and detergents is one strategy to reduce skin damage, dryness, and irritation. Irritant contact dermatitis is highest with preparations containing 4% chlorhexidine gluconate, less frequent with nonantimicrobial soaps and preparations containing lower concentrations of chlorhexidine gluconate, and lowest with well-formulated alcohol-based hand rubs containing emollients and other skin conditioners. Too few published data from comparative trials are available to reliably rank triclosan. Personnel should be reminded that it is neither necessary nor recommended to routinely wash hands after each application of an alcohol-based hand rub. Long-lasting improvement of compliance with hand hygiene protocols can be successful if an effective and accessible alcohol-based hand rub with a proven dermal tolerance and an excellent user acceptability is supplied, accompanied by education of health care workers and promotion of the use of the product.

Anaphylaxis during surgical and interventional procedures

OBJECTIVE

To describe the current evidence-based knowledge of the causes, diagnostic evaluation, and treatment of patients with anaphylaxis associated with surgical and interventional procedures.

DATA SOURCES

Articles published between 1966 and 2003 were identified in MEDLINE using the keywords anaphylactoid, anaphylaxis, anesthetics, antibiotics, cephalosporins, contrast media, colloids, flow cytometry, hypersensitivity, latex, neuromuscular depolarizing agents, neuromuscular nondepolarizing agents, penicillins, radioallergosorbent test, skin test, and vancomycin. Additional studies were identified from article reference lists.

STUDY SELECTION

Relevant, peer-reviewed original research articles and reviews.

RESULTS

Neuromuscular blocking agents, natural rubber latex, antibiotics, and induction agents are the most common causes of anaphylaxis during surgical and interventional procedures. Colloids, opioids, and radiocontrast media probably account for less than 10% of all reactions. Newer agents implicated in anaphylaxis include isosulphan blue and chlorhexidine. Skin tests are useful for evaluating allergic reactions to anesthetic agents and penicillins and for selecting alternative agents. Skin testing and specific IgE measurements for latex vary in allergen standardization and sensitivity and specificity, respectively. Flow cytometric allergen stimulation tests show promise in differentiating allergic from idiosyncratic ("pseudoallergic") reactions. Drug desensitization has been shown to be useful for penicillin anaphylaxis. Premedication with histamine receptor antagonists and corticosteroids helps prevent or attenuate radiocontrast media reactions.

CONCLUSIONS

Anaphylaxis during surgical and interventional procedures may be difficult to evaluate because of the rapid, successive use of multiple drugs or diagnostic agents. Careful analysis of anesthetic records and diagnostic tests for all the putative agents are necessary to ensure a complete evaluation.

Chlorhexidine anaphylaxis: case report and review of the literature

Chlorhexidine is a widely used antiseptic and disinfectant. Compared to its ubiquitous use in medical and non-medical environments, the sensitization rate seems to be low. Multivarious hypersensitivity reactions to the agent have been reported, including delayed hypersensitivity reactions such as contact dermatitis, fixed drug eruptions and photosensitivity reactions. An increasing number of immediate-type allergies such as contact urticaria, occupational asthma and anaphylactic shock have been reported. In the case report, we describe anaphylaxis due to topical skin application of chlorhexidine, confirmed by skin testing and sulfidoleukotriene stimulation test (CAST(R): cellular antigen stimulation test). The potential risk of anaphylactic reactions due to the application of chlorhexidine is well known, especially that application to mucous membranes can cause anaphylactic reactions and was therefore discouraged. The use of chlorhexidine at a 0.05% concentration on wounds and intact skin was so far thought to be safe. Besides our patient, only one other case of severe anaphylactic reaction due to application of chlorhexidine on skin has been reported. Hypersensitivity to chlorhexidine is rare, but its potential to cause anaphylactic shock is probably underestimated. This review should remind all clinicians of an important potential risk of this widely used antiseptic.

Vaginal chlorhexidine during labour to prevent early-onset neonatal group B streptococcal infection

BACKGROUND

Early-onset group B beta-hemolytic streptococcus (GBS) infection accounts for approximately 30% of neonatal infections, has a high mortality rate and is acquired through vertical transmission from colonized mothers. Several trials have demonstrated the efficacy of intrapartum chemoprophylaxis (IPC) for preventing early-onset disease (EOD). Vaginal disinfection with chlorhexidine during labour has been proposed as another strategy for preventing GBS EOD in the preterm and term neonate. Chlorhexidine has been found to have no impact on antibiotic resistance, is inexpensive, and applicable to poorly equipped delivery sites.

OBJECTIVES

To determine the effectiveness of vaginal disinfection with chlorhexidine during labour for preventing early-onset GBS infection in preterm and term neonates.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth trials register (October 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2003), MEDLINE (1966 to October 2003), EMBASE (1980 to March 2003), CINAHL (1982 to March 2003) and LILACS (1982 to September 2003).

SELECTION CRITERIA

Randomized and quasi-randomized trials comparing vaginal disinfection with chlorhexidine to placebo, or no treatment.

DATA COLLECTION AND ANALYSIS

We extracted information from the results sections of the included studies. We reported relative risk (RR) and risk difference (RD) with 95% confidence intervals (CI) for dichotomous outcomes. We calculated the number needed to treat (NNT) with 95% CIs when a statistically significant RD was found. We used a chi square test (chi2) and the I2 analysis to test for heterogeneity, and applied a fixed or random effects model accordingly.

MAIN RESULTS

Five studies, including approximately 2190 term and preterm infants, met the inclusion criteria and reported on at least one of the outcomes of interest for this systematic review. When all studies were combined there was a statistically significant (p = 0.005) reduction in colonisation (RR 0.72, 95% CI 0.56 to 0.91); RD -0.16 (95% CI -0.26 to -0.05); NNT 6 (95% CI 4 to 20). There was no statistically significant between-study heterogeneity. There was no statistically significant between-study heterogeneity both for RR (chi(2) = 3.21 [p = 0.2], I(2) = 37.8%) and for RD (chi(2) = 1.66 [p = 0.44], I(2) = 0%). There was no statistically significant reduction in EOD including GBS infection, GBS pneumonia, GBS meningitis or mortality.

REVIEWERS' CONCLUSIONS

Vaginal chlorhexidine resulted in a statistically significant reduction in GBS colonisation of neonates, but was not associated with reductions in other outcomes. The review currently does not support the use of vaginal disinfection with chlorhexidine in labour for preventing EOD. Results should be interpreted with caution as the methodological quality of the studies was poor.