Angioedema

Improving patient outcomes in hereditary angioedema: reducing attack frequency using routine prevention with C1 inhibitor concentrate

Hereditary angioedema (HAE) is a rare inherited disorder, characterised by recurrent oedema attacks in various regions of the body. In HAE, mutations in the C1 esterase inhibitor (C1-INH) gene result in decreased C1-INH concentrations (type I HAE) or functionally deficient C1-INH (type II HAE), leading to inappropriate activation of the kallikrein-kinin system and release of vasoactive mediators. Treatment of HAE aims to manage acute attacks (using replacement C1-INH or bradykinin B2 receptor antagonist) or prevent attacks through prophylaxis (using C1-INH or attenuated androgens). We present a case of a 67-year-old man with HAE who suffered a high number of breakthrough HAE attacks while undergoing long-term prophylaxis with attenuated androgens. Androgen therapy was safely discontinued and routine prevention therapy with C1-INH (1000 U) introduced as part of an individualised management approach, in line with published clinical trial data, which improved patient outcomes in terms of HAE attack frequency and severity.

Hereditary angioedema type III (estrogen-dependent) report of three cases and literature review

In this article, three cases of hereditary angioedema (HAE) type III (estrogen-dependent or with normal C1 inhibitor) are reported. The HAE was initially described in women of the same family in association with high-leveled estrogenic conditions such as the use of oral contraceptives and pregnancy. There is no change in the C1 inhibitor as happens in other types of hereditary angioedema, and mutations are observed in the encoding gene of the XII factor of coagulation in several patients. The current diagnosis is mainly clinical and treatment consists in the suspension of the triggering factors and control of acute symptoms. A brief review of physiopathology, clinical features, genetic alterations and treatment are also presented.

Guidance for diagnosis and treatment of acute angioedema in the emergency department: consensus statement by a panel of Italian experts

Angioedema attacks, characterized by the transient swelling of the skin and mucosae, are a frequent cause of visits to the emergency department. Swellings of the oral cavity, tongue, or larynx can result in life-threatening airway obstruction, while abdominal attacks can cause severe pain and often lead to unnecessary surgery. The underlying pathophysiologic process resulting in increased vascular permeability and plasma extravasation is mediated by vasoactive molecules, most commonly histamine and bradykinin. Based on the mediator involved, distinct angioedema forms can be recognized, calling for distinct therapeutic approaches. Prompt recognition is challenging for the emergency physician. The low awareness among physicians of the existence of rare forms of angioedema with different aetiologies and pathogenesis, considerably adds to the problem. Also poorly appreciated by emergency personnel may be the recently introduced bradykinin-targeted treatments. The main objective of this consensus statement is to provide guidance for the management of acute angioedema in the emergency department, from presentation to discharge or hospital admission, with a focus on identifying patients in whom new treatments may prevent invasive intervention.

Gastrointestinal manifestations, diagnosis, and management of hereditary angioedema

Abdominal pain is one of the most common conditions in clinical practice and yet a challenging complaint to accurately diagnose due to the vast number of possible etiologies. When other health care providers cannot identify the cause of abdominal pain, gastroenterologists are often looked upon to help solve the diagnostic dilemma. Consequently, it is incumbent upon gastroenterologists to be well versed in the diagnosis and management of not only common but also rare causes of abdominal pain. One such uncommon but well-described cause of abdominal pain is angioedema of the intestinal tract due to hereditary angioedema. Acute onset, recurrent abdominal pain of varying severity is its most common presenting symptom, and misdiagnosis can not only lead to unnecessary surgical procedures but also death. The purpose of this review is to raise awareness among gastroenterologists about hereditary angioedema as a potential cause of recurrent, unexplained abdominal pain.

Angioedema without urticaria in childhood

BACKGROUND

There has been no separate study investigating angioedema without urticaria (Aw/oU) exclusively in children so far. The purpose of this study was to investigate the frequency, clinical presentation, etiology, management and follow-up of Aw/oU in children.

METHODS

This is a prospective study that included all consecutive patients with a history of Aw/oU referred to our clinic between January 2011 and May 2012. A standard diagnostic and therapeutic algorithm was applied to all patients.

RESULTS

The frequency of Aw/oU was found to be 1.6% during the study period. An etiological factor could be found in only 45 patients (49%). The causes of Aw/oU were infection (21%), allergy (14%), thyroid autoimmunity (TA)-related (8%) and nonsteroid anti-inflammatory drug hypersensitivity (6%), and idiopathic angioedema (51%). There was no hereditary type I, II or acquired type of angioedema or rare syndromes associated with Aw/oU. The median follow-up was 16 months (range: 12-30 months). Antihistamine prophylaxis was initiated at therapeutic doses in 20 patients with frequently recurrent angioedema due to idiopathic and euthyroid TA-related Aw/oU for 3 months. These patients responded to antihistamine prophylaxis for 3 months. Four patients relapsed after cessation of prophylaxis at the end of 3 months. Antihistamine prophylaxis was prolonged to 6 months in three patients and to 9 months in one patient.

CONCLUSIONS

Angioedema without urticaria in children is a rare condition and no etiology can be identified in half of them. Antihistamine treatment alone is sufficient, and prognosis is good in recurrent non hereditary cases in a short-term follow-up period.

Retrospective study of drug-induced anaphylaxis treated in the emergency department or hospital: patient characteristics, management, and 1-year follow-up

BACKGROUND

Drugs are a common cause of anaphylaxis, which is potentially life threatening.

OBJECTIVE

We sought to describe US patients with an emergency department (ED) visit or hospitalization for drug-induced anaphylaxis (DIA), including postdischarge follow-up care.

METHODS

By using International Classification of Diseases, Ninth Revision codes in the MarketScan Database, we identified all patients with an ED visit and/or hospitalization for DIA between 2002 and 2008 (index date = initial ED visit and/or hospitalization). Inclusion required continuous full insurance coverage ≥1 year in the pre- and postindex period. We examined patient factors during the preindex period, characteristics of the index event, and outcomes during the postindex period.

RESULTS

The cohort included 716 patients with an ED visit and/or hospitalization for DIA (mean age, 48 years; 71% women). Most patients (71%) were managed in the ED, and only 8% of the patients with DIA treated in the ED received epinephrine. For those admitted, patients were hospitalized for a median of 3 days, and 41% spent time in the intensive care unit. Cardiorespiratory failure occurred in 5% of the patients in the ED and 23% of the patients who were hospitalized. The patients with a concomitant allergic condition were more likely to see an allergist/immunologist than those without a concomitant allergic condition, but 82% did not receive any subsequent care with an allergist/immunologist in the 1 year after the ED visit and/or hospitalization for DIA.

CONCLUSION

Drugs are a common, yet under-recognized, cause of anaphylaxis. Only a small number of patients with DIA received epinephrine in the ED or had subsequent care with an allergist/immunologist. These findings are novel and identify areas for improvement in the care of individuals with DIA.

Diagnosing angioedema

Angioedema usually occurs within the setting of allergic diseases or urticaria, but situations occur in which angioedema itself represents a disease, such as in hereditary angioedema. Evaluation of patients for recurrent angioedema without wheals must take into account both specific clinical signs and symptoms and specialized laboratory testing.

The impact of duration of treatment on reported time-to-onset in spontaneous reporting systems for pharmacovigilance

Within pharmacovigilance, knowledge of time-to-onset (time from start of drug administration to onset of reaction) is important in causality assessment of drugs and suspected adverse drug reactions (ADRs) and may indicate pharmacological mechanisms involved. It has been suggested that time-to-onset from individual case reports can be used for detection of safety signals. However, some ADRs only occur during treatment, while those that do occur later are less likely to be reported. The aim of this study was to investigate the impact of treatment duration on the reported time-to-onset. Case reports from the WHO Global ICSR database, VigiBase, up until February 5^th 2010 were the basis of this study. To examine the effect of duration of treatment on reported time-to-onset, angioedema and hepatitis were selected to represent short and long latency ADRs, respectively. The reported time-to-onset for each of these ADRs was contrasted for a set of drugs expected to be used short- or long-term, respectively. The study included 2,980 unique reports for angioedema and 1,159 for hepatitis. Median reported time-to-onset for angioedema in short-term treatments ranged 0-1 days (median 0.5), for angioedema in long-term treatments 0-26 days (median 8), for hepatitis in short-term treatments 4-12 days (median 7.5) and for hepatitis in long term treatments 19-73 days (median 28). Short-term treatments presented significantly shorter reported time-to-onset than long-term treatments. Of note is that reported time-to-onset for angioedema for long-term treatments (median value of medians being 8 days) was very similar to that of hepatitis for short-term treatments (median value of medians equal 7.5 days). The expected duration of treatment needs to be considered in the interpretation of reported time-to-onset and should be accounted for in signal detection method development and case evaluation.

In vitro comparison of bradykinin degradation by aliskiren, a renin inhibitor, and an inhibitor of angiotensin-converting enzyme

INTRODUCTION

Angiotensin-converting enzyme (ACE) inhibitors cause angioedema due to diminished degradation of bradykinin. Angiotensin receptor blockers may occasionally cause angioedema but the mechanism is unknown, and are generally considered safe, even in those who have reacted to ACE inhibitors. We determined whether aliskiren, a renin inhibitor, has an effect on the rate of bradykinin degradation.

METHODS

The ability of renin to metabolize bradykinin was studied and the rate of bradykinin degradation compared in the presence or absence of aliskiren. Enalapril, a known ACE inhibitor that causes angioedema served as positive control.

RESULTS

Renin was unable to digest bradykinin, indicating that a renin inhibitor is unlikely to affect the rate of bradykinin degradation. In a plasma system, aliskiren had no effect on the rate of bradykinin degradation while enalapril inhibited it appreciably. An inhibitory effect of aliskiren on the rate of bradykinin degradation by human pulmonary endothelial cells was observed, estimated to be about 5% of that of enalapril.

CONCLUSION

Aliskiren has no effect upon the rate of bradykinin degradation in plasma and a minimal effect employing vascular endothelial cells. The latter suggests inhibition of a non-renin enzyme that is a minor contributor to bradykinin degradation.

Simvastatin: A Risk Factor for Angioedema?

Objective:

To report a case of simvastatin-induced angioedema in a patient with near nightly episodes of orofacial angioedema.

Case Summary:

A 75-year-old African American female presented to the emergency department with recurrent face, lip, and tongue swelling. The patient described frequent episodes of orofacial edema, with 4 emergency department visits over the previous 6 months. Her home medications were reviewed and simvastatin was identified as a possible contributing medication. Simvastatin was discontinued with resolution of the symptoms during hospitalization and a significant reduction in episodes.

Discussion:

Drug-induced angioedema has been documented with several agents, most commonly angiotensin-converting enzyme inhibitors. The association with different drug classes has led to several postulated pathways for the development of angioedema. Notable mechanisms include mediation by bradykinin, inhibition of arachidonic acid metabolism, and complement activation. Each pathway culminates in increasing vascular permeability causing fluid accumulation in subcutaneous tissues. While statin use has been associated with drug-induced angioedema in postmarketing reports, there are no published cases involving simvastatin. Use of the Naranjo probability scale demonstrated a probable relationship between simvastatin use and the patient's recurrent angioedema.

Conclusions:

While statin use is not commonly associated with angioedema, clinicians must be aware of this possible adverse reaction. Consideration must also be given to potential drug interactions, increasing the risk of this adverse event.

Urticaria: attempts at classification

Among the many attempts to classify urticaria, 2 categories have been accepted worldwide, namely according to time course into acute (shorter than 6 weeks) and chronic urticaria (longer than 6 weeks) and a classification according to etiopathophysiology. A special subgroup is the physical urticarias where wheals are elicited via specific physical (mechanical, temperature, radiation) stimuli. In many forms of chronic urticaria, psychosomatic influences play a role. Despite great progress in modern immunology and allergology, chronic urticaria still remains a challenge for doctors and patients.

[Progress with management of hereditary angioedema]

Hereditary angioedema (HAE) is a rare type of angioedema caused by a quantitative or functional deficit of C1 inhibitor (C1 INH) that leads to excess production of bradykinin, which can result in acute localized swelling attacks in the skin or mucous membranes of the mouth, head and neck, extremities, gastrointestinal (GI) tract, genitals, trunk, and larynx. Angioedema in the respiratorytract maycause airway obstruction; severe abdominal pain, vomiting, or diarrhea may occur in the GI tract. Patients with HAE may be diagnosed and managed by HAE specialists or by primary care physicians depending on individual circumstances. Proper treatment requires differentiation from other forms of angioedema. Patients with HAE who are managed appropriately with medications that treat and prevent atttacks may have a lower risk of death from laryngeal edema and a better quality of life. Less frequent attacks may allow them to attend work, school, and leisure activities more regularlyand be free of the pain and disfigurement of HAE attacks moreoften.

WAO Guideline for the Management of Hereditary Angioedema

Hereditary Angioedema (HAE) is a rare disease and for this reason proper diagnosis and appropriate therapy are often unknown or not available for physicians and other health care providers. For this reason we convened a group of specialists that focus upon HAE from around the world to develop not only a consensus on diagnosis and management of HAE, but to also provide evidence based grades, strength of evidence and classification for the consensus. Since both consensus and evidence grading were adhered to the document meets criteria as a guideline. The outcome of the guideline is to improve diagnosis and management of patients with HAE throughout the world and to help initiate uniform care and availability of therapies to all with the diagnosis no matter where the residence of the individual with HAE exists.

Methylprednisolone sodium succinate-associated macroglossia in a critically ill patient

Allergic hypersensitivity reactions are a rare adverse effect of corticosteroids. Previous reports have identified patients who developed symptoms of urticaria, dyspnea, hypotension, bronchospasm, and angioedema occurring within minutes to an hour after corticosteroid administration. A 35-year-old woman is described who developed an atypical reaction of isolated macroglossia after receiving intravenous methylprednisolone sodium succinate for myasthenic crisis. Macroglossia was identified on day 2 of therapy and worsened through day 5. On day 5, she was transitioned to prednisone 50 mg daily administered by feeding tube. Tongue swelling improved by day 7 and on day 10, the patient was extubated. The patient required reintubation due to stridor, but received a tracheostomy and was weaned off mechanical ventilation by day 15. The reaction was not confirmed with skin-prick tests, intradermal tests, or a drug rechallenge; however, she had previously received and tolerated all other drugs administered during this time. Due to the timing of administration and onset of symptoms, we feel this adverse drug reaction was likely due to administration of methylprednisolone. Applying the Naranjo adverse drug reaction probability scale to this case, a score of six was obtained, indicating a probable association between the administration of methylprednisolone and the development of macroglossia. As intravenous corticosteroids are often used in the treatment of allergic reactions, they may be overlooked as a cause of macroglossia and other allergic reactions; therefore, practitioners need to be aware of the possibility of this adverse effect secondary to corticosteroid administration. In the event of methylprednisolone sodium succinate-induced macroglossia, alternative nonesterified corticosteroids, such as dexamethasone or prednisone, should be considered if continuation of therapy is required.

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.

Intramuscular Lipoma of the Tongue Masquerading as Angioedema

In most cases, the diagnostic evaluation of angioedema is challenging, as there are many possible etiologies. We report a case of an infiltrating lipoma of the tongue that masqueraded as angioedema. The patient, a 68-year-old man, presented with tongue swelling that had followed a waxing and waning course over a 6-month period. Physical examination showed a diffusely enlarged tongue with no discrete mass. A laboratory evaluation for angioedema was unremarkable. After the patient's condition did not respond to treatment with antihistamines and oral prednisone, a further workup was initiated. Magnetic resonance imaging of the neck and computed tomography of the oral cavity revealed only diffuse enlargement of the tongue. The patient underwent a tongue biopsy, which identified the cause of the swelling to be an infiltrating lipoma of the tongue. Clinicians should be aware that other causes of tongue swelling may mimic angioedema.

Recent advances in drug-induced angioedema

Angioedema is the end result of deep dermal, subcutaneous and/or mucosal swelling, and is potentially a life-threatening condition in cases where the pharynx or larynx is involved. Drug-induced angioedema has been reported to occur in response to a wide range of drugs and vaccines. Drug-induced angioedema, like other cutaneous drug reactions, has been reported to be most frequently elicited by beta-lactam antibiotics and non-steroidal anti-inflammatory drugs, although reliable data from epidemiologic studies are scarce. Recent reports suggested an increasing role of angiotensin-converting enzyme inhibitors (ACEIs) in the causation of life-threatening angioedema. ACEI-related angioedema is never accompanied by urticaria and occurs via a kinin-dependent mechanism. ACEI-related angioedema not only can start years after beginning the treatment, but it can then recur irregularly while under that treatment. Furthermore, allergy tests are unreliable for the diagnosis of ACEI-related angioedema, and so the relationship between angioedema and ACEIs is often missed and consequently quite underestimated. Accordingly, better understanding of the kinin-dependent mechanism, which is particular to angioedema, is necessary for the appropriate management of drug-induced angioedema.

Life-Threatening ACE Inhibitor-Induced Angioedema After Eleven Years on Lisinopril

Angiotensin-converting enzyme inhibitors (ACE-Is) are the primary medication class implicated in drug-associated angioedema. Angioedema is most common early in ACE-I therapy, yet episodes can occur late in therapy and have been reported even as late as 10 years after single treatment initiation. We present a case of a 65-year-old African American woman who experienced 2 episodes of angioedema, with the second being life threatening after receiving several concomitant agents known to cause angioedema, most notably lisinopril for 11 years.

Emerging concepts in the diagnosis and treatment of patients with undifferentiated angioedema

Angioedema is a sudden, transient swelling of well-demarcated areas of the dermis, subcutaneous tissue, mucosa, and submucosal tissues that can occur with or without urticaria. Up to 25% of people in the US will experience an episode of urticaria or angioedema during their lifetime, and many will present to the emergency department with an acute attack. Most cases of angioedema are attributable to the vasoactive mediators histamine and bradykinin. Histamine-mediated (allergic) angioedema occurs through a type I hypersensitivity reaction, whereas bradykinin-mediated (non-allergic) angioedema is iatrogenic or hereditary in origin.Although their clinical presentations bear similarities, the treatment algorithm for histamine-mediated angioedema differs significantly from that for bradykinin-mediated angioedema. Corticosteroids, and epinephrine are effective in the management of histamine-mediated angioedema but are ineffective in the management of bradykinin-mediated angioedema. Recent advancements in the understanding of angioedema have yielded pharmacologic treatment options for hereditary angioedema, a rare hereditary form of bradykinin-mediated angioedema. These novel therapies include a kallikrein inhibitor (ecallantide) and a bradykinin β2 receptor antagonist (icatibant). The physician's ability to distinguish between these types of angioedema is critical in optimizing outcomes in the acute care setting with appropriate treatment. This article reviews the pathophysiologic mechanisms, clinical presentations, and diagnostic laboratory evaluation of angioedema, along with acute management strategies for attacks.

Interaction between bradykinin and natriuretic peptides via RGS protein activation in HEK-293 cells

In this study, the interaction of natriuretic peptides (NP) and bradykinin (BK) signaling pathways was identified by measuring membrane potential (V(m)) and intracellular Ca(2+) using the patch-clamp technique and flow cytometry in HEK-293 cells. BK and NP receptor mRNA was identified using RT-PCR. BK (100 nM) depolarized cells activating bradykinin receptor type 2 (B(2)R) and Ca(2+)-dependent Cl(-) channels inhibitable by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB; 10 μM). The BK-induced Ca(2+) signal was blocked by the B(2)R inhibitor HOE 140. [Des-Arg(9)]-bradykinin, an activator of B(1)R, had no effect on intracellular Ca(2+). NP [atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and urodilatin] depolarized HEK-293 cells inhibiting K(+) channels. ANP, urodilatin, BNP [binding to natriuretic peptide receptor (NPR)-A] and 8-bromo-(8-Br)-cGMP inhibited the BK-induced depolarization while CNP (binding to NPR-Bi) failed to do so. The inhibitory effect on BK-triggered depolarization could be reversed by blocking PKG using the specific inhibitor KT 5823. BK-stimulated depolarization as well as Ca(2+) signaling was completely blocked by the phospholipase C (PLC) inhibitor U-73122 (10 nM). The inositol 1,4,5-trisphosphate receptor blocker 2-aminoethoxydiphenyl borate (2-APB; 50 μM) completely inhibited the BK-induced Ca(2+) signaling. UTP, another activator of the PLC-mediated Ca(2+) signaling pathway, was blocked by U-73122 as well but not by 8-Br-cGMP, indicating an intermediate regulatory step for NP via PKG in BK signaling such as regulators of G-protein signaling (RGS) proteins. When RGS proteins were inhibited by CCG-63802 in the presence of BK and 8-Br-cGMP, cells started to depolarize again. In conclusion, as natural antagonists of the B(2)R signaling pathway, NP may also positively interact in pathological conditions caused by BK.

Pressure-induced angioedema associated with endotracheal tube: successful treatment with epinephrine in two cases

Pressure-induced urticaria is a non-immunoglobulin E-mediated type of urticaria. Some patients only have angioedema, and the term pressure-induced angioedema (PIA) is more appropriate for them. PIA has not previously been reported in association with endotracheal tube. Here we describe two patients who developed PIA after endotracheal intubation. There were no histories of angioedema, drug and food allergy in both patients. Tests for specific aero-allergens and latex were negative. Serum total immunoglobulin E and C4 levels were in normal ranges. Antihistamines and intravenous steroid therapy were ineffective. Angioedema regressed with intravenous epinephrine infusion and did not relapse after extubation.

CONCLUSION

We suggest that endotracheal tubes can cause PIA. Epinephrine therapy should be used early at treatment, especially in the patients who are at great risk for life-threatening airway problems.

Development and construct validation of the angioedema quality of life questionnaire

BACKGROUND

Recurrent angioedema is a frequent clinical problem characterized by unpredictably and rapidly occurring cutaneous and mucosal swellings. These swellings may be painful and/or disfiguring. Upper airway involvement can also lead to dyspnea and suffocation. Although the disease burden is high, there is currently no specific instrument to measure health-related quality of life (QoL) impairment.

OBJECTIVE

To develop and validate the first symptom-specific tool to assess QoL impairment in recurrent angioedema patients, adhering to established methodological recommendations.

METHODS

During the development phase, 29 questions (items) were generated. Subsequently, item reduction was performed by means of impact analysis and factor analysis as well as by checking for content and face validity. As a result, 17 items were selected and included in the final instrument, the Angioedema QoL Questionnaire (AE-QoL). AE-QoL was then tested for its validity, reliability, and influence factors.

RESULTS

One hundred and ten angioedema patients took part in the validation of AE-QoL. AE-QoL was found to have a four-dimensional structure as well as a valid total score. All of its four domains (functioning, fatigue/mood, fears/shame, food) showed good levels of internal consistency with Cronbach's alpha > 0.8. Test-retesting revealed a good reliability of the instruments total score and domain scores. Gender as well as the patients' self-rated disease activity was found to be predictors of the AE-QoL total score.

CONCLUSIONS

Angioedema Quality of Life Questionnaire is the first angioedema-specific QoL questionnaire. It is a short, valid and reliable instrument that may serve as a valuable tool in future clinical studies and in routine patient care.

Angio-oedema induced by oestrogen contraceptives is mediated by bradykinin and is frequently associated with urticaria

BACKGROUND

Hereditary C1-inhibitor (C1-Inh) deficiency is associated with 'bradykinin-mediated angio-oedema' (BK-AO) and is believed not to be associated with urticaria. Acquired AO has been related to oestrogen contraceptives.

OBJECTIVE

To demonstrate that AO precipitated by oestrogens and characterized by nonfunctional C1-Inh is mediated by BK and to evaluate the occurrence of urticaria in these patients.

METHODS

A retrospective evaluation of patients referred for AO related to oestrogen was undertaken. Circulating C1-Inh, high molecular weight kininogen (HK) and enzymes involved in the metabolism of bradykinin were investigated.

RESULTS

Fifteen patients were included. HK cleavage concurrent to oestrogen intake was demonstrated in 10 patients with available plasma. Eight patients reported recurrent or chronic urticaria. Discontinuation of the contraceptive resulted in a return to native C1-Inh and HK in all cases studied and to normal kininogenase activity in all but one. The clinical manifestations completely disappeared in 6 patients and improved in 7 after the withdrawal of oestrogen.

CONCLUSION

Patients display extensive cleavage of HK in the plasma, which supports that AO precipitated by oestrogen contraception is BK-mediated. Recurrent urticaria may have been underestimated in this context. The presence of recurrent urticaria should not systematically rule out the diagnosis of BK-AO when the history is suggestive.

Fresh frozen plasma in the treatment of ACE inhibitor-induced angioedema

Angioedema secondary to the use of ACE-inhibitors is well recognised, with a high rate of airway intervention required. Several treatments have been described, but little evidence exists for any of them. We describe the successful use of fresh frozen plasma in two cases.

Safety of saxagliptin: rationale for and design of a series of postmarketing observational studies

PURPOSE

To describe the design and rationale of a series of postmarketing studies to examine the safety of saxagliptin, an oral dipeptidyl peptidase-4 inhibitor for the treatment of type 2 diabetes mellitus, in real-world settings.

METHODS

We are conducting a series of retrospective cohort studies using two UK (General Practice Research Database, and The Health Improvement Network) and two US (Medicare, HealthCore Integrated Research Database(SM) ) data sources. The primary outcomes of interest will include (i) hospitalization with acute liver failure, (ii) hospitalization for acute kidney injury, (iii) hospitalization for severe hypersensitivity reactions, (iv) hospitalization for severe infections, (v) hospitalization with infections associated with T-lymphocyte dysfunction (i.e., herpes zoster, tuberculosis, or nontuberculous mycobacteria), and (vi) major cardiovascular events. Diagnosis codes for the outcomes of interest will be validated by medical record review within each data source. Projected use and estimated incidence rates of outcomes of interest suggest there will be at least 80% statistical power to detect a minimum hazard ratio of 1.5 for major cardiovascular events, 2.0 for acute kidney injury and severe infections, 2.4 for acute liver failure, and 4.0 for severe hypersensitivity reactions.

RESULTS

Forthcoming.

CONCLUSIONS

This postmarketing safety assessment will provide important information regarding the safety of saxagliptin and could potentially identify important dipeptidyl peptidase-4 inhibitor class effects. The methods described may be useful to others planning similar evaluations.

The dermatology view of hereditary angio-oedema: practical diagnostic and management considerations

Hereditary angio-oedema (HAE) is characterized by recurrent, localized, non-pitting, non-pruritic, non-urticarial oedema. Nearly all patients experience skin swelling as a feature of HAE. There may be painful abdominal attacks, accompanied by nausea and vomiting. The disease is life-threatening should laryngeal oedema occur. HAE results from a deficiency or dysfunction of C1 inhibitor, a plasma protein with an important role in regulating the contact, complement and fibrinolytic systems. Effective management of HAE should include a plan for treatment of attacks, as well as routine and preprocedure prevention. Acute and prophylactic therapy with C1 inhibitor therapy for correcting the underlying deficiency in HAE is a valuable option.

Many faces of angioedema: focus on the diagnosis and management of abdominal manifestations of hereditary angioedema

Angioedema of the intestinal tract is an infrequent but well-described cause of abdominal pain that can occur because of inherited, acquired, allergic, or drug-induced causes. Hereditary angioedema (HAE) is a genetic disorder that causes recurrent attacks of severe edema of various body parts, including the intestinal tract. Moderate to severe abdominal pain occurs in 43-93% of such attacks due to intestinal edema. Laryngeal edema is a potentially life-threatening manifestation. Failure to recognize and diagnose HAE or other causes of intestinal angioedema can lead to years of delay in diagnosis, and in the case of HAE, often to unnecessary abdominal surgeries. Recognizing the typical history of recurrent attacks of abdominal pain, oropharyngeal/laryngeal angioedema or cutaneous angioedema, family history of similar symptoms, association of attacks with stress or menses, and exacerbation of attacks after administration of estrogens or angiotensin-converting enzyme inhibitors will increase diagnostic accuracy. Interdisciplinary treatment is often necessary after the diagnosis of HAE, first with acute management in the emergency room or the intensive care unit, followed by either drug prophylaxis against future attacks using a C1-esterase inhibitor concentrate or attenuated androgens and discontinuation of medications known to trigger attacks. Newer drugs approved for treatment of acute attacks may have future roles in the prevention of attacks if further studies support their efficacy. Gastroenterologists in particular should maintain a high index of suspicion for the possibility of HAE or other causes of intestinal angioedema in patients with a history of recurrent abdominal pain.

Diagnosis and management of hereditary angioedema: an emergency medicine perspective

BACKGROUND

Hereditary angioedema (HAE) is a rare and often debilitating condition associated with substantial morbidity and mortality in the absence of appropriate intervention. An underlying deficiency in functional C1-inhibitor (C1-INH) protein induces a vulnerability to unchecked activation of the complement, contact, and coagulation/fibrinolytic systems. The clinical consequence is a pattern of recurring attacks of non-pitting, non-pruritic edema, the urgency of which varies by the affected site. Laryngeal edema can escalate rapidly to asphyxiation, and severe cases of abdominal swelling can lead to hypovolemic shock.

OBJECTIVES

This report reviews the emergency diagnosis and treatment of hereditary angioedema and the impact of recently introduced treatments on treatment in the United States.

DISCUSSION

Until recently, emergency physicians in the United States were hindered by the lack of rapidly effective treatment options for HAE attacks. In this article, general clinical and laboratory diagnostic procedures are reviewed against the backdrop of two case studies: one patient presenting with a known history of HAE and one with previously undiagnosed HAE. In many countries outside the United States, plasma-derived C1-INH concentrate has for decades been the first-line treatment for acute attacks. The end of 2009 ushered in a new era in the pharmacologic management of HAE attacks in the United States with the approval of two new treatment options for acute treatment: a plasma-derived C1-INH concentrate and a kallikrein inhibitor.

CONCLUSION

With access to targeted and effective treatments, emergency physicians are now better equipped for successful and rapid intervention in urgent HAE cases.

Antihypertensive drug-induced angioedema causing upper airway obstruction in children

OBJECTIVE

Angioedema is a well-described complication arising from the use of antihypertensive agents in the adult population. However, its occurrence and potential for upper airway compromise in pediatrics has only been sporadically reported in the literature. Our objective is to report and review the occurrence of antihypertensive-induced angioedema in the pediatric population and the potential for airway compromise.

METHODS

Charts of 42 patients admitted to Cincinnati Children's Hospital Medical Center with the discharge diagnosis of angioedema (ICD-9 code 995.1) from January 2000 to January 2010 were reviewed. Of the 42 charts, 3 cases had angioedema induced by antihypertensive drugs and all 3 resulted in upper airway obstruction. Summary and findings of the data collected from the medical chart review included demographics, chief complaint(s), past medical history, hospital course, antihypertensive drugs used, diagnostic test(s), medical treatment, and time from onset of symptoms to resolution. In addition, a PubMed literature search using the terms angioedema and antihypertensive drugs was performed to review its occurrence in pediatrics. The previous literature case reports were compared to our cases to further characterize and emphasize the clinical features of this occurrence in children and adolescents.

RESULTS

Despite the well-known occurrence of antihypertensive drug-induced angioedema causing airway obstruction in adults, only 4 case reports have been previously published in children. At our institution, we describe 3 children who developed acute angioedema with upper airway obstruction after the chronic use of antihypertensive medications [2 drugs in the ACE inhibitor class (enalapril and lisinopril), and 1 drug in the calcium channel blocker class (CCB; amlodipine)]. In all 3 cases, the symptoms resolved within 1 week after the antihypertensive agent was discontinued.

CONCLUSION

Upper airway obstruction can occur at any age when taking antihypertensive drugs. Particular caution should be applied to ACE inhibitors and CCBs in this regard. With the increasing use of antihypertensive agents in the pediatric population, clinicians should be alert to the possibility of angioedema with upper airway obstruction as a potential lethal adverse effect.

Angioedema associated with dihydropyridine calcium-channel blockers in a child with Burkitt lymphoma

PURPOSE

A case of severe macroglossia and angioedema in a child with Burkitt lymphoma who was treated with two dihydropyridine calcium-channel blockers is reported.

SUMMARY

An eight-year-old white boy arrived at the pediatric emergency department with complaints of abdominal pain and distention after an episode of mild abdominal trauma. Physical examination results were significant for diffuse abdominal tenderness and distention, with a large palpable mass in the right quadrants. Computed tomography revealed a large abdominal mass, and a biopsy confirmed a diagnosis of Burkitt lymphoma. Before initiation of chemotherapy, the child developed tumor lysis syndrome, with subsequent renal failure and cardiorespiratory compromise. Once the patient was stabilized and sedated on mechanical ventilation, tumor-directed chemotherapy was initiated, and rapid tumor regression ensued. To control episodes of hypertension, nicardipine was initiated and titrated to achieve the blood pressure goals. Three days after initiation of nicardipine therapy, the child developed facial swelling and significant, protruding macroglossia. Eight days after nicardipine initiation, a tracheotomy was required due to upper airway obstruction; at that time, the patient was converted to amlodipine administered via nasogastric tube for continued blood pressure control. The boy's macroglossia persisted for another 18 days, until a multi-disciplinary drug therapy review resulted in the discontinuation of amlodipine. Within one week of the withdrawal of amlodipine, the child's macroglossia was completely resolved.

CONCLUSION

An eight-year-old boy with Burkitt lymphoma developed severe macroglossia and angioedema when treated with nicardipine. The reaction persisted throughout treatment with amlodipine and resolved quickly after amlodipine was withdrawn.

Ecallantide is a novel treatment for attacks of hereditary angioedema due to C1 inhibitor deficiency

Hereditary angioedema (HAE) resulting from the deficiency of the C1 inhibitor protein is a rare disease, characterized by paroxysms of edema formation in the subcutis and in the submucosa. Edema can cause obstruction of the upper airway, which may lead to suffocation. Prompt elimination of edema is necessary to save patients from this life-threatening condition. Essentially, these edematous attacks are related to the activation of the kinin-kallikrein system and the consequent release of bradykinin. Ecallantide (known as DX-88 previously), a potent and specific inhibitor of plasma kallikrein is an innovative medicinal product. This is the only agent approved recently by the FDA for all localizations of edematous HAE attacks. Its advantages include no risk of viral contamination, high selectivity, very rapid onset of action, good tolerability, and straightforward subcutaneous administration. Owing to the risk of anaphylaxis, ecallantide should be administered by a health care professional. A postmarketing survey to improve risk-assessment and risk-minimization has been launched. The results of these studies may lead to the approval of ecallantide for self-administration.

Prescriptions for self-injectable epinephrine in emergency department angioedema management

BACKGROUND

Angioedema is often treated in the emergency department (ED). Few studies have evaluated self-injectable epinephrine (SIE) prescribing patterns for angioedema.

OBJECTIVES

To describe presentation and management of ED patients with angioedema and determine factors associated with epinephrine administration, hospital admission and SIE prescription.

METHODS

We conducted a retrospective cohort study of all ED patients with angioedema between January 2005 and December 2006.

RESULTS

Of 63 patients, 39 (61.9%) were female. Median age was 49 years. Precipitating factors were identified in 36 (57.1%) patients. History of other allergic conditions was seen in 37 (58.7%) patients. Seventeen (27.0%) patients received epinephrine, 55 (87.3%) received antihistamines, and 51 (81.0%) received steroids. Epinephrine was administered more commonly in patients with edema of the tongue (risk ratio [RR], 5.28, 95% confidence interval [CI] 1.95-14.33, P = .0003), tightness/fullness of throat (RR, 3.31, 95% CI 1.62-6.76, P = .006), and dyspnea/wheeze (RR, 3.04, 95% CI 1.41-6.59, P = .005). Hospitalization was more common in patients with dyspnea/wheeze (P = .028) and allergic history (P = .006). Thirteen patients (22.0%) were discharged with SIE. An SIE prescription was associated with younger patients (median age, 26 years [interquartile range (IQR) 15-50] vs a median age 57.5 years [IQR 43-68], P = .004) and patients with throat tightness/fullness (RR, 4.2, 95% CI 1.8-9.8, P = .005).

CONCLUSION

Patients with respiratory symptoms and allergic history were likely to be admitted. Epinephrine use was more frequent in patients with signs and symptoms of oropharyngeal edema. Younger patients and those with tightness/fullness of throat were likely to be prescribed SIE. Further studies are needed to determine who would benefit from epinephrine use and SIE prescription.

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.

Hereditary Angioedema: A Clinical Review for the Otolaryngologist

Hereditary angioedema (HAE) is a relatively rare genetic disorder that is usually characterized by either low levels of C1 esterase inhibitor (C1-INH) or the presence of dysfunctional C1-INH. It can present with relatively mild and self-limiting symptoms, but it is also potentially fatal; the most common cause of death is asphyxiation secondary to edema of the upper airway. The diagnosis of HAE, especially in the emergency situation, is not straightforward. HAE must be distinguished from several other types of angioedema that require different management approaches. Management approaches include trigger avoidance and pharmacologic therapy; the latter has traditionally involved the administration of attenuated androgens and antifibrinolytics. Recently, a new class of agent—C1-INH—has been introduced in the United States. This article provides an update on the pathophysiology, clinical picture, diagnosis, prophylaxis, and acute treatment of HAE. We must keep HAE in mind as a possible diagnosis whenever we are faced with a case of unexplained angioedema if we are to take advantage of the effective and more specific therapies that are becoming available.

Angioedema due to C1 inhibitor deficiency in 2010

Angioedema is a recurrent, non-pitting, non-pruritic, self-limiting swelling due to transient increase of endothelial permeability in the capillaries of the deep cutaneous and mucosal layers. Two main groups of angioedema should be distinguished based on the response to treatment: those responding to antihistamine and those that do not. Among the last ones, angioedema due to inherited (hereditary angioedema) and acquired (acquired angioedema) C1 inhibitor deficiency are the best defined, and are known to be mediated by bradykinin. The clinical picture is characterized by cutaneous, abdominal, and laryngeal symptoms that are highly disabling, and can be lethal when they affect the larynx, or if they are not promptly and adequately treated. Important advances in diagnosis and treatment of C1 inhibitor deficiency have been made in recent years, and today, we can rely on different therapeutic options to prevent symptoms or to treat those already present. Because of these advances, in patients properly diagnosed and treated, the mortality for the disease has dropped close to zero, and the quality of life for patients approaches that of normal subjects.

Omalizumab therapy in three patients with chronic autoimmune urticaria

Chronic urticaria is a common skin disease. In about 45% of patients the cause is an autoantibody directed at the α-subunit of the high-affinity IgE receptor (chronic autoimmune urticaria; CAU). Omalizumab is a monoclonal anti-IgE antibody that has a proven role in the treatment of various allergic diseases. We gave omalizumab once every month for 16 weeks to three patients that were refractory to standard treatment, including high doses of antihistamines, leukotriene receptor antagonist, and corticosteroid. There was dramatic improvement in the primary efficacy variable--the change in mean urticaria activity score (UAS) from baseline (i.e., the average over the first 4-week period before omalizumab) to the final 4-week period of omalizumab treatment. There was improvement in the secondary efficacy variables, which included change from baseline in interference with sleep, interference with daily activities, daily diary record of urticaria signs and symptoms based on a scoring system, and rescue medication use. These improvements persisted for 12 weeks after discontinuation of the drug. Omalizumab may have a role in treating refractory cases of CAU.