Angioedema and angiotensin-converting enzyme inhibitors: Are demographics a risk?

Tranexamic acid for angiotensin-converting enzyme inhibitor-induced angioedema

Approximately 0.7% of patients taking angiotensin-converting enzyme inhibitors (ACEIs) develop ACEI-induced angioedema (ACEI-IA). With no approved treatments for ACEI-IA, the risk of complications is concerning. Tranexamic acid (TXA) has the potential to prevent intubations and resolve ACEI-IA by inhibiting the downstream production of bradykinin. In this review, we aim to evaluate the safety and efficacy of TXA use in ACEI-IA. We queried the PubMed database for studies involving TXA for ACEI-IA from January 2003 to January 2023. Seven studies met the study inclusion criteria. Our results demonstrate that TXA may improve angioedema symptoms and prevent intubation. In addition, its availability, low cost, and safety profile support its use for improving the symptoms and complications of ACEI-IA in an emergency setting.

Exome Sequencing Reveals Common and Rare Variants in F5 Associated With ACE Inhibitor and Angiotensin Receptor Blocker-Induced Angioedema

Angioedema occurring in the head and neck region is a rare and sometimes life-threatening adverse reaction to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). Few studies have investigated the association of common variants with this extreme reaction, but none have explored the combined influence of rare variants yet. Adjudicated cases of ACEI-induced angioedema (ACEI-AE) or ARB-induced angioedema (ARB-AE) and controls were recruited at five different centers. Sequencing of 1,066 samples (408 ACEI-AE, ARB-AE, and 658 controls) was performed using exome-enriched sequence data. A common variant of the F5 gene that causes an increase in blood clotting (rs6025, p.Arg506Gln, also called factor V Leiden), was significantly associated with both ACEI-AE and ARB-AE (odds ratio: 2.85, 95% confidence interval (CI), 1.89-4.25). A burden test analysis of five rare missense variants in F5 was also found to be associated with ACEI-AE or ARB-AE, P = 2.09 × 10-3 . A combined gene risk score of these variants, and the common variants rs6025 and rs6020, showed that individuals carrying at least one variant had 2.21 (95% CI, 1.49-3.27, P = 6.30 × 10-9 ) times the odds of having ACEI-AE or ARB-AE. The increased risk due to the common Leiden allele was confirmed in a genome-wide association study from the United States. A high risk of angioedema was also observed for the rs6020 variant that is the main coagulation defect-causing variant in black African and Asian populations. We found that deleterious missense variants in F5 are associated with an increased risk of ACEI-AE or ARB-AE.

Genome-wide association study of angioedema induced by angiotensin-converting enzyme inhibitor and angiotensin receptor blocker treatment

Angioedema in the mouth or upper airways is a feared adverse reaction to angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) treatment, which is used for hypertension, heart failure and diabetes complications. This candidate gene and genome-wide association study aimed to identify genetic variants predisposing to angioedema induced by these drugs. The discovery cohort consisted of 173 cases and 4890 controls recruited in Sweden. In the candidate gene analysis, ETV6, BDKRB2, MME, and PRKCQ were nominally associated with angioedema (p < 0.05), but did not pass Bonferroni correction for multiple testing (p < 2.89 × 10⁻⁵). In the genome-wide analysis, intronic variants in the calcium-activated potassium channel subunit alpha-1 (KCNMA1) gene on chromosome 10 were significantly associated with angioedema (p < 5 × 10⁻⁸). Whilst the top KCNMA1 hit was not significant in the replication cohort (413 cases and 599 ACEi-exposed controls from the US and Northern Europe), a meta-analysis of the replication and discovery cohorts (in total 586 cases and 1944 ACEi-exposed controls) revealed that each variant allele increased the odds of experiencing angioedema 1.62 times (95% confidence interval 1.05–2.50, p = 0.030). Associated KCNMA1 variants are not known to be functional, but are in linkage disequilibrium with variants in transcription factor binding sites active in relevant tissues. In summary, our data suggest that common variation in KCNMA1 is associated with risk of angioedema induced by ACEi or ARB treatment. Future whole exome or genome sequencing studies will show whether rare variants in KCNMA1 or other genes contribute to the risk of ACEi- and ARB-induced angioedema.

Inhalant allergen sensitization is an independent risk factor for the development of angioedema

BACKGROUND/OBJECTIVE

The etiology and risk factors for angioedema remain poorly understood with causative triggers often going undiagnosed despite repeated reactions. The purpose of this study was to determine the relationship between inhalant allergen sensitization and angioedema.

METHODS

A retrospective review of patients who had in vitro inhalant allergy testing from 2006 to 2010 was performed. Patients with a diagnosis of angioedema who underwent inhalant allergy testing were identified. Analyses for co-morbidities, class of sensitization, seasonal timing of angioedema, and concurrent use of known hypertensive medications that can cause angioedema were performed.

RESULTS

There were 1000 patients who underwent inhalant allergy testing and qualified for the study. 37/1000 had at least one episode of angioedema and of these patients, 34 had positive inhalant sensitization testing results. Multivariate regression models showed overall sensitization status, seasonal allergen and epidermal/mite sensitization as independent risk factors (p<0.001, p=0.005, p=0.025 respectively) when controlling for ACE inhibitor use and other covariates. Tree, and epidermal/mite sensitizations were independent risk factors for angioedema in mono-sensitized subject analysis (p=0.028, p=0.029, respectively).

CONCLUSION

Both seasonal and perennial allergen sensitizations are independent risk factors for the development of angioedema. In patients with angioedema and an unknown trigger, inhalant allergen sensitization should be considered as a potential contributing factor to the development of angioedema.

Meta-analysis of genome-wide association studies on the intolerance of angiotensin-converting enzyme inhibitors

OBJECTIVES

To identify single nucleotide polymorphisms (SNPs) associated with switching from an angiotensin-converting enzyme (ACE)-inhibitor to an angiotensin receptor blocker.

METHODS

Two cohorts of patients starting ACE-inhibitors were identified within the Rotterdam Study in the Netherlands and the Genetics of Diabetes Audit and Research in Tayside Scotland study in Scotland. Cases were intolerant patients who switched from an ACE-inhibitor to an angiotensin receptor blocker and controls were individuals who used ACE-inhibitors continuously for at least 2 years and did not switch. Genome-wide association study (GWAS) using an additive model was run in these sets and the results were meta-analysed using Genome-Wide Association Meta Analysis software.

RESULTS

A total of 972 cases out of 5161 ACE-inhibitor starters were identified. Eight SNPs within four genes reached the genome-wide association study significance level (P<5×10) in the meta-analysis [RNA binding protein, Fox-1 homolog (Caenorhabditis elegans), γ-aminobutyric acid receptor subunit γ-2, sarcoma (Src) homology 2 (SH2) B adaptor protein 1 and membrane bound O-acyltransferase domain containing 1]. The strongest associated SNP was located in an intron of RNA binding protein, Fox-1 homolog (Caenorhabditis elegans), which contains an RNA binding protein [rs2061538: minor allele frequency=0.16, odds ratio=1.52 (95% confidence interval: 1.32-1.76), P=6.2×10].

CONCLUSION

These results indicate that genetic variation in the above-mentioned genes may increase the risk of ACE-inhibitor-induced adverse reactions.

Comparison of Clinical Factors Between Patients With Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema and Cough

BACKGROUND

Angioedema is a rare and serious adverse drug reaction (ADR) to angiotensin-converting enzyme (ACE) inhibitor treatment. Dry cough is a common side effect of ACE inhibitors and has been identified as a possible risk factor for angioedema.

OBJECTIVE

We compared characteristics between patients with ACE inhibitor-induced angioedema and cough with the aim of identifying risk factors that differ between these adverse events.

METHODS

Data on patients with angioedema or cough induced by ACE inhibitors were collected from the Swedish database of spontaneously reported ADRs or from collaborating clinicians. Wilcoxon rank sum test, Fisher's exact test, and odds ratios (ORs) with 95% CIs were used to test for between-group differences. The significance threshold was set to P <0.00128 to correct for multiple comparisons.

RESULTS

Clinical characteristics were compared between 168 patients with angioedema and 121 with cough only. Smoking and concomitant selective calcium channel blocker treatment were more frequent among patients with angioedema than cough: OR = 4.3, 95% CI = 2.1-8.9, P = 2.2 × 10^-5, and OR = 3.7, 95% CI = 2.0-7.0, P = 1.7 × 10^-5. Angioedema cases were seen more often in male patients (OR = 2.2, 95% CI = 1.4-3.6, P = 1.3 × 10^-4) and had longer time to onset and higher doses than those with cough ( P = 3.2 × 10^-10 and P = 2.6 × 10^-4). A multiple model containing the variables smoking, concurrent calcium channel blocker treatment, male sex, and time to onset accounted for 26% of the variance between the groups.

CONCLUSION

Smoking, comedication with selective calcium channel blockers, male sex, and longer treatment time were associated with ACE inhibitor-induced angioedema rather than cough.

Epidemiology of ACE Inhibitor Angioedema Utilizing a Large Electronic Health Record

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) are a common cause of drug-induced angioedema in the United States. Most epidemiologic ACEI angioedema data are from large multicenter clinical trials.

OBJECTIVE

The objective of this study was to identify the incidence of and risk factors for ACEI angioedema using a large integrated electronic health record (EHR).

METHODS

We conducted a retrospective cohort study of all ACEI prescriptions in the outpatient setting of a large academic center between January 1, 2000, and September 30, 2008. We determined frequency, timing, and risk factors for ACEI angioedema within 5 years of prescription. All data were derived from EHR sources, with angioedema defined by EHR reactions of angioedema, swelling, edema, or lip, eye, face, tongue, throat or mouth swelling.

RESULTS

Among 134,945 patients prescribed an ACEI, 0.7% (n = 888) developed angioedema during the subsequent 5 years. Sex was similar but patients who developed ACEI angioedema were younger (61.5 vs 62.7 years, P = .007). Patients with ACEI angioedema were more likely to have a history of nonsteroidal anti-inflammatory drug allergy compared with patients who did not develop angioedema (7.1% vs 4.2%, P < .001). We identified a 0.07% incidence of ACEI angioedema within 1 month of prescription and a 0.23% incidence during the first year. Incidence of angioedema was relatively constant annually over the subsequent 4 years (0.10% to 0.12%).

CONCLUSIONS

The incidence of ACEI angioedema within a large EHR is consistent with large clinical trial data. We observed a persistent and relatively constant annual risk; however, angioedema risk factors and underlying genetic and pathophysiological mechanisms require further study.

Assessment of 105 Patients with Angiotensin Converting Enzyme-Inhibitor Induced Angioedema

Objective. To asses a cohort of 105 consecutive patients with angiotensin converting enzyme-inhibitor induced angioedema with regard to demographics, risk factors, family history of angioedema, hospitalization, airway management, outcome, and use of diagnostic codes used for the condition. Study Design. Cohort study. Methods. This was a retrospective cohort study of 105 patients with angiotensin converting enzyme-inhibitor induced angioedema in the period 1995-2014. Results. The cohort consisted of 67 females and 38 males (F : M ratio 1.8), with a mean age of 63 [range 26-86] years. Female gender was associated with a significantly higher risk of angiotensin converting enzyme-inhibitor induced angioedema. 6.7% had a positive family history of angioedema. Diabetes seemed to be a protective factor with regard to angioedema. 95% experienced angioedema of the head and neck. 4.7% needed intubation or tracheostomy. 74 admissions took place during the study period with a total of 143 days spent in the hospital. The diagnosis codes most often used for this condition were "DT783 Quincke's oedema" and "DT78.4 Allergy unspecified". Complement C1 inhibitor was normal in all tested patients. Conclusion. Female gender predisposes to angiotensin converting enzyme-inhibitor induced angioedema, whereas diabetes seems to be a protective factor.

Angioedema: Classification, management and emerging therapies for the perioperative physician

Angioedema is a rare condition which manifests as sudden localised, non-pitting swelling of certain body parts including skin and mucous membranes. It is vital that anaesthesiologists understand this condition, as it may present suddenly in the perioperative period with airway compromise. To identify literature for this review, the authors searched the PubMed, Medline, Embase, Scopus and Web of Science databases for English language articles covering a 10-year period, 2006 through 2016. Angioedema can be either mast-cell mediated or bradykinin-induced. Older therapies for histaminergic symptoms are well known to anaesthesiologists (e.g., adrenaline, anti-histamines and steroids), whereas older therapies for bradykinin-induced symptoms include plasma and attenuated androgens. New classes of drugs for bradykinin-induced symptoms are now available, including anti-bradykinin, plasma kallikrein inhibitor and C1 esterase inhibitors. These can be used prophylactically or as rescue medications. Anaesthesiologists are in a unique position to coordinate perioperative care for this complex group of patients.

Infections and edema

Infectious and inflammatory conditions of the head and neck may present with impaired airways. An understanding of the pathophysiology will allow for accurate diagnosis and prompt intervention. Preintervention discussion and planning by members of the airway team are crucial in developing a primary and backup plans for safely securing the airway.

Angiotensin-converting Enzyme Inhibitor Angioedema Requiring Admission to an Intensive Care Unit

OBJECTIVE

The purpose of this study was to review consecutive cases of angiotensin-converting enzyme (ACE) inhibitor angioedema admitted to an intensive care unit.

METHODS

Fifty subjects with ACE-inhibitor angioedema admitted from 1998-2011 were reviewed.

RESULTS

All 50 subjects were men, 62.8 ± 8.4 years of age, 76% African Americans. Fifteen (30%) required ventilatory support and 2 (4%) required tracheostomy. Over half (56%) had taken ACE inhibitors for over a year. Logistic regression identified dyspnea and tongue involvement with the need for ventilatory support (P < .01). Hypercapnia (PaCO2 = 45.2 ± 6.7; P = 0.046) also identified patients needing ventilatory support.

CONCLUSIONS

Ventilatory support was provided for about one-third of those with ACE inhibitor-associated angioedema. Angioedema can occur even after extended use. Dyspnea and tongue involvement identified patients requiring ventilatory support.

Potentially lethal ACE-inhibitor-induced angioedema in a child

We report a case of a 9-year-old female with known end-stage kidney disease who presented with sudden onset tongue swelling. A diagnosis of angiotensin-converting enzyme inhibitor-induced angioedema related to bradykinin accumulation was made. Her symptoms resolved shortly after discontinuation of captopril. Early diagnosis can save patients from severe upper airway obstruction.

Angiotensin converting enzyme inhibitor-related angioedema: onset, presentation, and management

OBJECTIVE

This study aimed to determine the duration of use, presentation, and management of angiotensin converting enzyme (ACE) inhibitor-related angioedema patients at an urban academic medical center.

METHODS

Retrospective chart review.

RESULTS

Eighty-eight patients who presented with ACE inhibitor-related angioedema between January 1, 2012, and December 31, 2012, were identified. They presented anywhere from 1 day to 20 years after starting an ACE inhibitor. About half the patients (50.7%) presented after taking an ACE inhibitor for at least 1 year. Fifty-five patients were female (62.5%). Twenty-eight patients (31.8%) had an airway intervention with 27 intubated and 1 requiring cricothyroidotomy. Six patients were intubated after more than 1 flexible laryngoscopy. The percentage of patients with involvement of the face, lips, tongue, floor of mouth, soft palate/uvula, and larynx were 12.5%, 60.2%, 39.7%, 6.8%, 17.0%, and 29.5%, respectively. Sixty-eight percent of patients with laryngeal edema were intubated. The majority of patients were treated with a corticosteroid and H1 and H2 receptor antagonists.

CONCLUSION

Angioedema can occur at any time after starting ACE inhibitor use, with nearly half occurring after 1 year of use. Laryngeal involvement occurred in a minority of patients, but most of these patients were felt to require airway protection.

Factors affecting the development of adverse drug reactions (Review article)

OBJECTIVES

To discuss the effect of certain factors on the occurrence of Adverse Drug Reactions (ADRs).

DATA SOURCES

A systematic review of the literature in the period between 1991 and 2012 was made based on PubMed, the Cochrane database of systematic reviews, EMBASE and IDIS. Key words used were: medication error, adverse drug reaction, iatrogenic disease factors, ambulatory care, primary health care, side effects and treatment hazards.

SUMMARY

Many factors play a crucial role in the occurrence of ADRs, some of these are patient related, drug related or socially related factors. Age for instance has a very critical impact on the occurrence of ADRs, both very young and very old patients are more vulnerable to these reactions than other age groups. Alcohol intake also has a crucial impact on ADRs. Other factors are gender, race, pregnancy, breast feeding, kidney problems, liver function, drug dose and frequency and many other factors. The effect of these factors on ADRs is well documented in the medical literature. Taking these factors into consideration during medical evaluation enables medical practitioners to choose the best drug regimen.

CONCLUSION

Many factors affect the occurrence of ADRs. Some of these factors can be changed like smoking or alcohol intake others cannot be changed like age, presence of other diseases or genetic factors. Understanding the different effects of these factors on ADRs enables healthcare professionals to choose the most appropriate medication for that particular patient. It also helps the healthcare professionals to give the best advice to patients. Pharmacogenomics is the most recent science which emphasizes the genetic predisposition of ADRs. This innovative science provides a new perspective in dealing with the decision making process of drug selection.

Angioedema of the upper aerodigestive tract: risk factors associated with airway intervention and management algorithm

BACKGROUND

Angioedema of the upper aerodigestive tract can lead to significant airway obstruction. To date no articles have delineated risk factors for progression after initial evaluation.

METHODS

This article presents the results of a retrospective study of patients with angioedema at a single institution. Patients included were consecutive otolaryngology consultations for angioedema in the emergency department (ED) from 1999 to 2003. All patients were evaluated by an otolaryngologist and underwent fiber-optic laryngoscopy, which was repeated serially depending on findings. Data was collected on demographics, comorbidities, intubation, disposition, and progression of angioedema.

RESULTS

A total of 177 patients were included in the study: 32 (18%) patients required intubation; 25 (14%) on initial presentation and 7 (4%) who progressed from an initially stable airway to requiring intervention after reevaluation. Analysis of variance (ANOVA) demonstrated a statistically significant variance between location of edema and rate of intubation, with higher rates in the pharynx and larynx vs the lip and face. Patients who required intubation after progression between serial evaluations were statistically more likely to have edema that involved deeper portions of the aerodigestive tract. Patients who required intubation were statistically more likely to be older (average age 61.8 vs 55.1 years, p = 0.03).

CONCLUSION

In this large series of patients managed for aerodigestive angioedema we demonstrate risk factors associated with airway intervention, and risk factors associated with clinical progression on serial examination to airway intervention. In addition, we demonstrate a successful management algorithm for patients with aerodigestive angioedema.

Pharmacogenetics of ACE inhibitor-induced angioedema and cough: a systematic review and meta-analysis

AIM

Angioedema and cough are the two most important adverse effects of ACE inhibitors (ACEIs). Evidence exists that ACEI-related angioedema/cough is partly genetically determined and several genes have been identified to play a role in the development of ACEI-related adverse effects.

MATERIALS & METHODS

This study was performed in order to evaluate the evidence of these genetic associations and ACEIs' adverse effects. After removing duplicates and critical appraisal, 19 studies were considered to be eligible to review; 14 articles about cough and five articles about angioedema. A separate meta-analysis was performed for the most studied ACE insertion/deletion polymorphism (rs4646994) and its association with cough.

RESULTS & CONCLUSION

One gene region (XPNPEP2) was associated with ACEI-induced angioedema in three studies. In our meta-analysis we did not find a significant association between the ACE insertion/deletion polymorphism and ACEI cough.

Angioedema--assessment and treatment

BACKGROUND

Angioedema has numerous hereditary, acquired and iatrogenic causes. A number of studies show that angioedema is inadequately assessed and treated during its acute phase as well as in the follow-up period. We present an algorithm for the assessment and treatment of patients with angioedema. KNOWLEDGE BASE: The article is based on a literature search in PubMed, a review of bibliographies and the authors' clinical experience and research.

RESULTS

The majority of angioedema patients have accompanying urticaria. Pathophysiologically, angioedemas are divided into histaminergic and non-histaminergic forms. In a large group of patients no positive trigger is identified. On assessment in hospital the most frequently identified cause is drug intake, normally angiotensin-converting-enzyme inhibitors and NSAIDs , while allergic/pseudoallergic and idiopathic reactions are more commonly seen in general practice. There are a number of rare causes of angioedema, all of which are important to keep in mind. The acute and prophylactic treatment will depend on the subtype of angioedema and is best provided through cross-disciplinary collaboration.

INTERPRETATION

Angioedema is a potentially life-threatening condition and should be assessed and treated systematically. It is important to remember that angioedema is either histaminergic or non-histaminergic, as the treatment of the two types is different.

Management of angiotensin-converting enzyme inhibitor-induced angioedema

OBJECTIVES/HYPOTHESIS

To develop and validate a clinical algorithm for management of patients with angiotensin-converting enzyme inhibitor-induced angioedema (AIIA).

STUDY DESIGN

Prospective cohort observational study.

METHODS

Over 1 year, 40 patients with AIIA were evaluated by otolaryngology, underwent laryngoscopy, and were followed until disease resolution. The need for airway intervention, disposition for appropriate level of care, and other parameters were analyzed.

RESULTS

Treatment started within 61.5 minutes of presentation to the emergency department (ED). Mean duration until resolution of edema was 29 hours. Twenty (50%) patients required intensive care unit (ICU) admission, and six (15%) required intubation. Seventeen (42.5%) were monitored and discharged from the ED. Floor-of-mouth edema was present in 19 (47.5%), and massive tongue edema was found in four (10%) patients. The aryepiglottic fold was involved in 20 (50%) patients on laryngoscopy. Older patients (P = .048) with subjective dyspnea (P = .003) and dysphonia (P = .001) were most likely to require ICU admission. Upper lip swelling had a negative correlation with airway edema identifiable on laryngoscopy alone (P = .008). Dysphonia (n = 16) predicted airway edema upon laryngoscopy (P = .001). All 40 patients were triaged successfully without the need for readmission or escalation of level of care.

CONCLUSIONS

The management protocol was successful in 40 consecutive patients to the appropriate level of care. History and physical examination may predict airway findings identified on laryngoscopy and help guide management when treatment by otolaryngology is not immediately available. A subset of patients will require acute airway intervention and can be identified at initial presentation.

Angioedema: a review of 367 episodes presenting to three tertiary care hospitals

OBJECTIVES

We evaluated the clinical characteristics of patients treated for angioedema, and determined the factors associated with the clinical course.

METHODS

We performed a chart review of 367 episodes presenting from 1997 through 2008.

RESULTS

The mean (+/-SD) age was 51.8 +/- 20.1 years; 65.7% of the episodes occurred in female patients; 62.4% of the episodes were in African American patients. The patients were on angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) for 49.1% of the episodes, and an inciting factor (diet change, minor trauma, or exposure to fumes) was present for 21.5%. We found that 75.7% of the episodes were type 1 angioedema, 5.7% were type 2, 1.4% were type 3, and 17.2% involved multiple sites; 58% of the episodes required admission. For 3.3% of the episodes, the patients were intubated, and in 0.3% of the episodes, the patients required a tracheostomy. Logistic regression identified non-African American race, allergies, alcohol use, use of ACE inhibitors or ARBs, multiple sites, and age as associated with the need for admission. Bivariate analysis identified age, multiple affected sites, stridor, hoarseness, dysphagia, and drooling as associated with intubation or tracheostomy.

CONCLUSIONS

The novel findings of this study are lower rates of airway intervention than reported previously and the fact that multiple affected sites were associated with admission and intubation or tracheostomy, particularly when the edema involved the larynx or hypopharynx.

Site involvement as a predictor of airway intervention in angioedema

OBJECTIVES/HYPOTHESIS

To look for a relationship between which sites are involved in angioedema and the need for airway intervention (intubation, tracheotomy).

STUDY DESIGN

Retrospective chart review.

METHODS

Charts of 140 patients who were admitted to two hospitals at an academic medical center between July 1, 2006 and June 30, 2008 with the diagnosis of angioedema were reviewed. Charts were reviewed for pertinent data, including demographics, sites of involvement along the upper airway, medical therapy, and airway intervention. Subsites included lips, anterior tongue, floor of mouth, soft palate, base of tongue (BOT), and larynx.

RESULTS

The BOT was involved in 19 patients and the larynx was involved in 29 patients. Airway intervention was required in 21 patients (16%). Patients with laryngeal and/or BOT involvement required intervention in 38% of cases (vs. 7% in patients without involvement). Patients with more than three sites involved had a 39% rate of intervention, compared with only 12% in patients with less than three sites involved. Among those patients with laryngeal/BOT involvement, 56% with more than three sites involved required intervention, as compared to 30% of patients with less than three sites involved.

CONCLUSIONS

Site of involvement was found to correlate with airway intervention. Involvement of anterior tongue, BOT, and larynx significantly increased the likelihood of intubation or tracheostomy, as did involvement of multiple sites. Thorough evaluation, including fiberoptic laryngoscopy, can aid in determining which patients require airway intervention.

ACE Inhibitor-Induced Angioedema of the Bowel

Angiotensin converting enzyme inhibitor ACEI-induced angioedema of the intestine is a rare occurrence and often unrecognized complication of ACEI. We present a case of a 45-year-old Hispanic female with angioedema of the small bowel progressing to facial and oral pharyngeal angioedema. Patients are typically middle-aged females on ACEI therapy who present to the emergency department with abdominal pain, nausea, vomiting, and diarrhea. This is a diagnosis of exclusion, and physicians must have a high index of suspicion to make the diagnosis. Symptoms typically resolve within 24–48 hours after ACE inhibitor withdrawal. Recognizing these signs and symptoms, and discontinuing the medication, can save a patient from unnecessary, costly, and invasive procedures.

Angiotensin converting enzyme inhibitor induced angio-oedema: a review of the pathophysiology and risk factors

Angio-oedema (AE) is a known adverse effect of angiotensin converting enzyme inhibitor (ACE-I) therapy. Over the past several decades, evidence of failure to diagnose this important and potentially fatal reaction is commonly found in the literature. Because this reaction is often seen first in the primary care setting, a review was undertaken to analyse and document the keys to both diagnostic criteria as well as to investigate potential risk factors for ACE-I AE occurrence. A general review of published literature was conducted through Medline, EMBASE, and the Cochrane Database, targeting ACE-I-related AE pathomechanism, diagnosis, epidemiology, risk factors, and clinical decision making and treatment. The incidence and severity of AE appears to be on the rise and there is evidence of considerable delay in diagnosis contributing to significant morbidity and mortality for patients. The mechanism of AE due to ACE-I drugs is not fully understood, but some genomic and metabolomic information has been correlated. Additional epidemiologic data and clinical treatment outcome predictors have been evaluated, creating a basis for future work on the development of clinical prediction tools to aid in risk identification and diagnostic differentiation. Accurate recognition of AE by the primary care provider is essential to limit the rising morbidity associated with ACE-I treatment-related AE. Research findings on the phenotypic indicators relevant to this group of patients as well as basic research into the pathomechanism of AE are available, and should be used in the construction of better risk analysis and clinical diagnostic tools for ACE-I AE.