Anaphylactic deaths in Auckland, New Zealand: a review of coronial autopsies from 1985 to 2005

Liquid chromatography with tandem mass spectrometric method for determination of 52 antibiotics in human whole blood and urine and application to forensic cases

PURPOSE

A rapid and reliable method was developed and validated for the simultaneous analysis of 52 antibiotics (cephalosporins, penicillins, carbapenems, lincosamides, quinolones, nitroimidazoles, macrolides, sulfonamides, tetracyclines, glycopeptide) in urine and whole blood by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

METHOD

Analytes were extracted by dilution or protein precipitation and analyzed on an Agilent 1260 HPLC system coupled to an Agilent 6470 Triple Quadrupole Mass Spectrometer.

RESULTS

The method attended method validation criteria. The limits of detection were equal or lower than 2.0 ng/mL, whereas the limits of quantification ranged from 0.1 to 10.0 ng/mL, from 0.1 to 5.0 ng/mL, in urine and whole blood, respectively. For all analytes, the bias and intra- and inter-day precision values were less than 14.7%. The ranges of recovery values of all antibiotics were 76.5-124.5% in whole blood and 76.3-121.8% in urine, values of the effects were lower than 25% in two matrices. No evidence of carryover was observed. The study of sample stability showed that almost all analytes were stable at 24 °C for 24 h, all analytes were stable at -20 °C for 14 days and at -80 °C for 30 days. Freeze-thaw cycles stability showed that antibiotics were stable except for imipenem. Autosampler stability study showed that all analytes were stable for 24 h, except for imipenem and amoxicillin. Applicability was proven by analyzing authentic whole blood (n = 86) and urine (n = 79) samples from patients under antibiotics treatment. Therefore, this method was applied to the analysis 3 forensic allergy cases, which were positive for at least one analyte.

CONCLUSIONS

A simple, sensitive and high-throughput method for the simultaneous determination of different classes of antibiotics in urine and whole blood samples was developed and applied. This sensitive method was successfully applied to forensic cases.

DNA methylation profiling reveals potential biomarkers of β-lactams induced fatal anaphylactic shock

Anaphylaxis is a serious reaction of systemic hypersensitivity with that rapid onset and sudden death. Drug hypersensitivity, particularly induced by β-lactams, is one of the most frequent causes of anaphylaxis in adults. But identification of anaphylactic shock, in forensic sciences recently, is difficult, because it mainly depends on nonspecific characteristic morphological changes, as well as exclusion and circumstantial evidence. Here, we detected DNA methylation signatures of β-lactams-induced fatal anaphylactic shock with the Illumina Infinium Human Methylation EPIC BeadChip, to screen potential forensic biomarkers and reveal the molecular mechanisms of drug-induced anaphylaxis with fatal shock and sudden death. Our results indicated that DNA methylation was associated with β-lactams-induced fatal anaphylactic shock, in which the hypomethylation played a vital role. We found that 1459 differentially methylated positions (DMPs) were mainly involved in β-lactams-induced fatal anaphylactic shock by regulating MAPK and other signaling pathways. 18 DNA methylation signatures that could separate β-lactams-induced anaphylactic shock from healthy individuals were identified. The altered methylation of DMPs can affect the transcription of corresponding genes and promote β-lactams-induced fatal anaphylactic shock. The results suggest that DNA methylation can detect forensic identification markers of drug-induced anaphylaxis with fatal shock and sudden death, and it is an effective method for the forensic diagnosis.

Combined Treatment with KV Channel Inhibitor 4-Aminopyridine and either γ-Cystathionine Lyase Inhibitor β-Cyanoalanine or Epinephrine Restores Blood Pressure, and Improves Survival in the Wistar Rat Model of Anaphylactic Shock

Simple Summary

Allergic diseases are presenting a constant increase all over the world and caused by such different substances as food, drugs, and pollens. Anaphylactic shock is the more severe complication of allergy which can induce death if the treatment is not administered immediately. Some patients do not respond to the recommended treatment, intra venous or intramuscular epinephrine. The pathophysiology of anaphylactic shock is still under investigation. The mediators released after the activation of mast cells and basophiles act on endothelial cells and smooth muscle cells, inducing the vasodilation responsible for hypotension and shock. Nitric oxide and hydrogen sulphide are both intracellular mediators that induce vasodilation. The role of potassium voltage dependent channels is suspected. We aimed to demonstrate the ability of a blocker of potassium voltage dependent channels, 4-aminopyridine, alone or in combination with inhibitors of cystathionine γ-lyase to restore blood pressure and improve survival in an ovalbumin rat anaphylactic shock model. The blockade of potassium voltage dependent channels alone or combined with inhibitors of cystathionine γ-lyase, dl-propargylglycine, or β-cyanoalanine restored blood pressure and improved survival. These findings suggest possible investigative treatment pathways for research concerning epinephrine-refractory anaphylactic shock in patients.

Abstract

The mechanism of anaphylactic shock (AS) remains incompletely understood. The potassium channel blocker 4-aminopyridine (4-AP), the inhibitors of cystathionine γ-lyase (ICSE), dl-propargylglycine (DPG) or β-cyanoalanine (BCA), and the nitric oxide (NO) synthase produce vasoconstriction and could be an alternative for the treatment of AS. The aim of this study was to demonstrate the ability of L-NAME, ICSE alone or in combination with 4-AP to restore blood pressure (BP) and improve survival in ovalbumin (OVA) rats AS. Experimental groups included non-sensitized Wistar rats (n = 6); AS (n = 6); AS (n = 10 per group) treated i.v. with 4-AP (AS+4-AP), epinephrine (AS+EPI), AS+DPG, AS+BCA, or with L-NAME (AS+L-NAME); or AS treated with drug combinations 4-AP+DPG, 4-AP+BCA, 4-AP+L-NAME, or 4-AP+EPI. AS was induced by i.v. OVA (1 mg). Treatments were administered i.v. one minute after AS induction. Mean arterial BP (MAP), heart rate (HR), and survival were monitored for 60 min. Plasma levels of histamine, prostaglandin E2 (PGE2) and F2 (PGF2α), leukotriene B4 and C4, angiotensin II, vasopressin, oxidative stress markers, pH, HCO3, PaO2, PaCO2, and K+ were measured. OVA induced severe hypotension and all AS rats died. Moreover, 4-AP, 4-AP+EPI, or 4-AP+BCA normalized both MAP and HR and increased survival. All sensitized rats treated with 4-AP alone or with 4-AP+BCA survived. The time-integrated MAP “area under the curve” was significantly higher after combined 4-AP treatment with ICSE. Metabolic acidosis was not rescued and NO, ICSE, and Kv inhibitors differentially alter oxidative stress and plasma levels of anaphylactic mediators. The AS-induced reduction of serum angiotensin II levels was prevented by 4-AP treatment alone or in combination with other drugs. Further, 4-AP treatment combined with EPI or with BCA also increased serum PGF2α, whereas only the 4-AP+EPI combination increased serum LTB4. Serum vasopressin and angiotensin II levels were increased by 4-AP treatment alone or in combination with other drugs. Moreover, 4-AP alone and in combination with inhibition of cystathionine γ-lyase or EPI normalizes BP, increases serum vasoconstrictor levels, and improves survival in the Wistar rat model of AS. These findings suggest possible investigative treatment pathways for research into epinephrine-refractory anaphylactic shock in patients.

Anaphylactic cardiovascular collapse manifesting as myocardial infarction following salad consumption. A case of Kounis variant type I syndrome

Anaphylactic cardiovascular events constitute an underrated cause of medical emergencies in hospitalized patients. Coronary arteries and myocardium are targeted by anaphylactic mediators leading to acute coronary syndrome and imminent cardiovascular collapse. Early diagnosis and high clinical suspicion are required to secure prompt life-saving treatment in these cases. However, physicians of both Cardiology and Internal Medicine Departments are not familiar with this condition. Recently, we diagnosed and treated a case of anaphylactic cardiovascular collapse manifesting as acute myocardial infarction following salad consumption. Notably, Kounis anaphylaxis-associated acute coronary syndrome is a rare cause of ST segment elevation myocardial infarction with normal or diseased coronary arteries. We recommend that Kounis syndrome and its variants should be taken into consideration in the differential diagnosis of ischemic heart disease in patients with signs of allergic reaction and/or medical history of previous allergic reactions, who experience acute coronary syndrome after exposure to certain environmental stimuli. (www.actabiomedica.it)

A longitudinal study of hymenoptera stings in preschool children

BACKGROUND

Insect venom is the second most common cause of anaphylaxis outside of medical encounters. Stings cause over 20% of all anaphylactic deaths and 7% of anaphylaxis in children. To date, there have been no longitudinal studies of insect sting events or allergy in preschool children.

METHODS

A prospective longitudinal nested observational study in the BASELINE Birth Cohort Study (n = 2137). Sting-related questions were asked at 6 and 12 months and 2 and 5 years. Skin prick testing (SPT) was performed at 2 and 5 years. SpIgE testing was performed on selected cases at 2 years.

RESULTS

Seventy-seven children (6.8%) were stung by the age of 2. Of these, 25 (32.5%) reported adverse reactions (four systemic). Eleven (0.9%) had positive SPT at 2 years (eight bee, two wasp, one both). Four stung children had positive SPT. Two (one stung, one never stung) had positive spIgE to a venom component at 2 years. A total of 268 children (21.9%) were stung by 5 years, 144 (52.1%) reporting local reactions and none systemic. Four children (0.4%) had positive SPT at 5 years: one bee and three wasp. Of the 11 SPT-positive children at 2 years, none were still positive at 5 years.

CONCLUSION

This is the first longitudinal study of the natural history of hymenoptera stings and allergy in preschool children. Hymenoptera venom allergy is less common in this cohort than in adults. Systemic reactions were not medically documented in this population, in keeping with previous literature. This study confirms the poor correlation of IgE sensitization to venom with sting allergy and does not support the common parental request to screen children for sting allergy.

Death by anaphylactic shock in an institution: an accident or negligence?

This is a description of a man, institutionalised for learning difficulties, known to have an allergy to seafood. After eating a pie, the patient quickly developed dyspnoea and vomiting. The staff at the institution administered epinephrine and called the emergency services. Despite cardiopulmonary resuscitation, the patient died shortly after being admitted to the emergency department of the University Hospitals of Geneva. In the light of the circumstances of the death and of a discrepancy between the information given to the police by the staff at the institution looking after the patient on the one hand, and the preliminary elements of the investigation on the other hand, it was suspected that there was failure in care of the patient and our institute was asked to carry out an autopsy. Basing on all the investigations carried out, the cause of death was anaphylactic reaction following the ingestion of seafood, contrary to what had been alleged by the staff at the home.

Anaphylactic cardiovascular collapse and Kounis syndrome: systemic vasodilation or coronary vasoconstriction?

The first reported human anaphylactic death is considered to be the Pharaoh Menes death, caused by a wasp sting. Currently, anaphylactic cardiovascular events represent one of most frequent medical emergencies. Rapid diagnosis, prompt and appropriate treatment can be life saving. The main concept beyond anaphylaxis lies to myocardial damage and ventricular dysfunction, thus resulting in cardiovascular collapse. Cardiac output depression due to coronary hypoperfusion from systemic vasodilation, leakage of plasma and volume loss due to increased vascular permeability, as well as reduced venous return, are regarded as the main causes of cardiovascular collapse. Clinical reports and experiments indicate that the human heart, in general, and the coronary arteries, in particular, could be the primary target of the released anaphylactic mediators. Coronary vasoconstriction and thrombosis induced by the released mediators namely histamine, chymase, tryptase, cathepsin D, leukotrienes, thromboxane and platelet activating factor (PAF) can result to further myocardial damage and anaphylaxis associated acute coronary syndrome, the so-called Kounis syndrome. Kounis syndrome with increase of cardiac troponin and other cardiac biomarkers, can progress to heart failure and cardiovascular collapse. In experimental anaphylaxis, cardiac reactions caused by the intracardiac histamine and release of other anaphylactic mediators are followed by secondary cardiovascular reactions, such as cardiac arrhythmias, atrioventricular block, acute myocardial ischemia, decrease in coronary blood flow and cardiac output, cerebral blood flow, left ventricular developed pressure (LVdp/dtmax) as well as increase in portal venous and coronary vascular resistance denoting vascular spasm. Clinically, some patients with anaphylactic myocardial infarction respond satisfactorily to appropriate interventional and medical therapy, while anti-allergic treatment with antihistamines, corticosteroids and fluid replacement might be ineffective. Therefore, differentiating the decrease of cardiac output due to myocardial tissue hypoperfusion from systemic vasodilation and leakage of plasma, from myocardial tissue due to coronary vasoconstriction and thrombosis might be challenging during anaphylactic cardiac collapse. Combined antiallergic, anti-ischemic and antithrombotic treatment seems currently beneficial. Simultaneous measurements of peripheral arterial resistance and coronary blood flow with newer diagnostic techniques including cardiac magnetic resonance imaging (MRI) and myocardial scintigraphy may help elucidating the pathophysiology of anaphylactic cardiovascular collapse, thus rendering treatment more rapid and effective.

Fatal Anaphylaxis: Mortality Rate and Risk Factors

Up to 5% of the US population has suffered anaphylaxis. Fatal outcome is rare, such that even for people with known venom or food allergy, fatal anaphylaxis constitutes less than 1% of total mortality risk. The incidence of fatal anaphylaxis has not increased in line with hospital admissions for anaphylaxis. Fatal drug anaphylaxis may be increasing, but rates of fatal anaphylaxis to venom and food are stable. Risk factors for fatal anaphylaxis vary according to cause. For fatal drug anaphylaxis, previous cardiovascular morbidity and older age are risk factors, with beta-lactam antibiotics, general anesthetic agents, and radiocontrast injections the commonest triggers. Fatal food anaphylaxis most commonly occurs during the second and third decades. Delayed epinephrine administration is a risk factor; common triggers are nuts, seafood, and in children, milk. For fatal venom anaphylaxis, risk factors include middle age, male sex, white race, cardiovascular disease, and possibly mastocytosis; insect triggers vary by region. Upright posture is a feature of fatal anaphylaxis to both food and venom. The rarity of fatal anaphylaxis and the significant quality of life impact of allergic conditions suggest that quality of life impairment should be a key consideration when making treatment decisions in patients at risk for anaphylaxis.

Fatal anaphylaxis registries data support changes in the who anaphylaxis mortality coding rules

Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction. The difficulty of coding anaphylaxis fatalities under the World Health Organization (WHO) International Classification of Diseases (ICD) system is recognized as an important reason for under-notification of anaphylaxis deaths. On current death certificates, a limited number of ICD codes are valid as underlying causes of death, and death certificates do not include the word anaphylaxis per se. In this review, we provide evidences supporting the need for changes in WHO mortality coding rules and call for addition of anaphylaxis as an underlying cause of death on international death certificates. This publication will be included in support of a formal request to the WHO as a formal request for this move taking the 11^th ICD revision.

The Three-Herb Formula Shuang-Huang-Lian stabilizes mast cells through activation of mitochondrial calcium uniporter

Mast cells (MCs) are key effector cells of IgE-FcεRI- or MrgprX2-mediated signaling event. Shuang-Huang-Lian (SHL), a herbal formula from Chinese Pharmacopoeia, has been clinically used in type I hypersensitivity. Our previous study demonstrated that SHL exerted a non-negligible effect on MC stabilization. Herein, we sought to elucidate the molecular mechanisms of the prominent anti-allergic ability of SHL. MrgprX2- and IgE-FcεRI-mediated MC activation in vitro and in vivo models were developed by using compound 48/80 (C48/80) and shrimp tropomyosin (ST), respectively. Our data showed that SHL markedly dampened C48/80- or ST-induced MC degranulation in vitro and in vivo. Mechanistic study indicated that cytosolic Ca²⁺ (Ca²⁺_[c]) level decreased rapidly and sustainably after SHL treatment, and then returned to homeostasis when SHL was withdrawn. Moreover, SHL decreases Ca²⁺_[c] levels mainly through enhancing the mitochondrial Ca²⁺ (Ca²⁺_[m]) uptake. After genetically silencing or pharmacologic inhibiting mitochondrial calcium uniporter (MCU), the effect of SHL on the Ca²⁺_[c] level and MC degranulation was significantly weakened. Simultaneously, the activation of SHL on Ca²⁺_[m] uptake was completely lost. Collectively, by activating MCU, SHL decreases Ca²⁺_[c] level to stabilize MCs, thus exerting a remarkable anti-allergic activity, which could have considerable influences on clinical practice and research.

Epidemiology of anaphylaxis

Knowledge about the epidemiology of anaphylaxis is based on data from various sources: clinical practice, large secondary clinical and administrative databases of primary care or hospitalized patients, and recent surveys with representative samples of the general population. As several similar results are often reported in several publications and populations, such findings are highly like to be robust. One such finding is that the incidence and prevalence of anaphylaxis are higher than previously thought. Publications from the last 5 years reveal an incidence of between 50 and 112 episodes per 100 000 person-years; estimated prevalence is 0.3-5.1% depending on the rigour of the definitions used. Figures are higher in children, especially those aged 0-4 years. Publications from various geographical areas based on clinical and administrative data on hospitalized patients suggest that the frequency of admissions due to anaphylaxis has increased (5-7-fold in the last 10-15 years). Other publications point to a geographic gradient in the incidence of anaphylaxis, with higher frequencies recorded in areas with few hours of sunlight. However, these trends could be the result of factors other than a real change in the incidence of anaphylaxis, such as changes in disease coding and in the care provided. Based on data from the records of voluntary declarations of death by physicians and from large national databases, death from anaphylaxis remains very infrequent and stands at 0.35-1.06 deaths per million people per year, with no increases observed in the last 10-15 years. Although anaphylaxis can be fatal, recurrence of anaphylaxis--especially that associated with atopic diseases and hymenoptera stings--affects 26.5-54% of patients.

Drug-Induced Anaphylaxis in Latin American Countries

BACKGROUND

Information regarding the clinical features and management of drug-induced anaphylaxis (DIA) in Latin America is lacking.

OBJECTIVE

The objective of this study was to assess implicated medications, demographics, and treatments received for DIA in Latin American patients referred to national specialty centers for evaluation.

METHOD

A database previously used to compile information on drug-induced allergic reactions in 11 Latin American countries was used to identify and characterize patients presenting specifically with a clinical diagnosis of DIA. Information regarding clinical presentation, causative agent(s), diagnostic studies performed, treatment, and contributing factors associated with increased reaction severity was analyzed.

RESULTS

There were 1005 patients evaluated for possible drug hypersensitivity reactions during the study interval, and 264 (26.3%) met criteria for DIA. DIA was more frequent in adults and in elderly females (N = 129 [76.6%] and N = 30 [75%], respectively) compared with children and/or adolescents (N = 21 [42.9%], P < .01). Severe DIA was less frequent with underlying asthma (N = 22 vs 35 [38.6% vs 61.4%], P < .05) or atopy (N = 62 vs 71 [43% vs 59% ], P < .01). Nonsteroidal anti-inflammatory drugs (NSAIDs) (N = 178 [57.8%]), beta-lactam antibiotics (N = 44 [14.3%]), and other antibiotics (N = 16 [5.2%]) were the most frequently implicated drug classes. Anaphylaxis was rated as severe in N = 133 (50.4%) and anaphylactic shock (AS) was present in N = 90 (34.1%). Epinephrine was only used in N = 73 (27.6%) overall, but in N = 70 (77.8%) of patients with AS.

CONCLUSION

In Latin American patients referred for evaluation of DIA, NSAIDs and antibiotics were implicated in approximately 80% of cases. Most of these reactions were treated in the emergency department. Epinephrine was administered in only 27.6% of all cases, although more frequently for anaphylactic shock. Dissemination of anaphylaxis guidelines among emergency department physicians should be encouraged to improve management of DIA.

Fatal anaphylaxis in the United States, 1999-2010: temporal patterns and demographic associations

BACKGROUND

Anaphylaxis-related deaths in the United States have not been well characterized in recent years.

OBJECTIVES

We sought to define epidemiologic features and time trends of fatal anaphylaxis in the United States from 1999 to 2010.

METHODS

Anaphylaxis-related deaths were identified by using the 10th clinical modification of the International Classification of Diseases system diagnostic codes on death certificates from the US National Mortality Database. Rates were calculated by using census population estimates.

RESULTS

There were a total of 2458 anaphylaxis-related deaths in the United States from 1999 to 2010. Medications were the most common cause (58.8%), followed by "unspecified" (19.3%), venom (15.2%), and food (6.7%). There was a significant increase in fatal drug-induced anaphylaxis over 12 years: from 0.27 (95% CI, 0.23-0.30) per million in 1999 to 2001 to 0.51 (95% CI, 0.47-0.56) per million in 2008 to 2010 (P < .001). Fatal anaphylaxis caused by medications, food, and unspecified allergens was significantly associated with African American race and older age (P < .001). Fatal anaphylaxis to venom was significantly associated with white race, older age, and male sex (P < .001). The rates of fatal anaphylaxis to foods in male African American subjects increased from 0.06 (95% CI, 0.01-0.17) per million in 1999 to 2001 to 0.21 (95% CI, 0.11-0.37) per million in 2008 to 2010 (P < .001). The rates of unspecified fatal anaphylaxis decreased over time from 0.30 (95% CI, 0.26-0.34) per million in 1999 to 2001 to 0.09 (95% CI, 0.07-0.11) per million in 2008 to 2010 (P < .001).

CONCLUSION

There are strong and disparate associations between race and specific classes of anaphylaxis-related mortality in the United States. The increase in medication-related deaths caused by anaphylaxis likely relates to increased medication and radiocontrast use, enhanced diagnosis, and coding changes.

Pediatric Natural Deaths

Autopsies are important in the investigation of childhood deaths. Most natural deaths are unlikely to come to the attention of the forensic pathologist, particularly in cases where death occurs in hospital. During the neonatal period (up to 28 days of age), deaths most commonly occur as a result of prematurity and related conditions, chromosomal abnormalities, or congenital malformations. Beyond the neonatal period, trauma-related deaths and sudden infant death syndrome are more common. In terms of natural acquired diseases of childhood, certain conditions are prevalent based on age and may be encountered at autopsy. Common acquired diseases that cause death in infants and children up to 5 years of age include pneumonia and other respiratory diseases, other infectious diseases, and malignancies. In older children, mortality due to natural disease declines substantially with trauma being the major cause of death, and malignancies the major cause of acquired disease. Sudden and/or unexpected deaths in which a natural disease state was previously unknown are most likely to come under the jurisdiction of the medical examiner or coroner and may be related to an underlying natural disease. Depending on the underlying disease process, the approach can differ, and therefore familiarity with common causes of death during childhood is important in order to focus the autopsy so that special techniques can be used along with obtaining proper ancillary testing to arrive at an accurate diagnosis and cause of death.

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.

Postmortem serum tryptase levels in anaphylactic and non-anaphylactic deaths

BACKGROUND

The postmortem diagnosis of anaphylaxis remains difficult due to the lack of specific biomarkers. Mast cell tryptase (MCT) levels are used as a marker of mast cell degranulation in living patients and elevated levels have also been described in postmortem serum samples in anaphylaxis-associated deaths, although elevated levels may also be seen in non-anaphylaxis-associated deaths.

OBJECTIVE

To investigate the effects of cause of death, site of blood sampling, degree of sample haemolysis and the presence of opiates on postmortem MCT levels.

METHOD

We obtained sera from three collection sites from 189 non-suspicious coronial postmortems and aortic samples from 10 anaphylactic deaths to characterise postmortem MCT.

RESULTS

MCT were elevated (>11.4 μg/L) in 57% of aortic samples, 58% of femoral samples and 30% of subclavian samples. In aortic samples, there were significantly higher levels of MCT in anaphylaxis-associated deaths compared with other causes of death. Aortic MCT levels >110 μg/L had a sensitivity of 80% and specificity of 92.1% for anaphylaxis-associated deaths. There was a significant correlation between MCT and degree of sample haemolysis but no correlation with the presence of opiates.

CONCLUSIONS

Moderately elevated MCT levels are common in postmortem sera. Aortic values >110 μg/L may support a diagnosis of anaphylaxis-associated death, although the diagnosis should not be based on this test alone. There was significant variation between sample sites and reference ranges for individual sample sites should be established.

Management of insect sting hypersensitivity: an update

Reactions to Hymenoptera insect stings are common. While most are self-limited, some induce systemic allergic reactions or anaphylaxis. Prompt recognition, diagnosis, and treatment of these reactions are important for improving quality-of-life and reducing the risk of future sting reactions. This review summarizes the current recommendations to diagnose and treat Hymenoptera sting induced allergic reactions and highlights considerations for various populations throughout the world.

Anaphylaxis related to fentanyl citrate

Anaphylaxis is a fulminant, unexpected, immunoglobulin E-mediated allergic reaction that can be triggered by multiple agents. Common causative agents include neuromuscular blocking drugs, latex, antibiotics, colloids, hypnotics, and opioids. Fentanyl citrate, however, is an extremely unusual cause of anaphylaxis. Pulmonary edema, although uncommon in anaphylaxis, can be a prominent feature, as was in one of the patient. An adverse drug reaction is a noxious or unintended reaction to a drug that is administered in standard doses by the proper route for the purpose of prophylaxis, diagnosis, or treatment. Reactions are classified into two major subtypes: type A, which are dose dependent and predictable; and type B, which are not dose dependent and unpredictable. Unpredictable reactions include immune (allergic) or no immune drug hypersensitivity reactions and are related to genetic susceptibilities or undefined mechanisms (formally called idiosyncratic and intolerance reactions). A drug allergy is always associated with an immune mechanism for which evidence of drug-specific antibodies or activated T lymphocytes can be shown. In the last few years, many novel drugs have entered clinical practice (i.e., biologic agents) generating novel patterns of drug hypersensitivity reactions. As old drugs continue to be used, new clinical and biologic techniques enable improvement in the diagnosis of these reactions.

An update on epidemiology of anaphylaxis in children and adults

PURPOSE OF REVIEW

The purpose of the present review is to describe the epidemiology of food-induced, medication-induced, drug-induced, and insect sting-induced anaphylaxis; to summarize recent changes in the incidence of anaphylaxis internationally; and to discuss recent insights into potential risk factors for anaphylaxis.

RECENT FINDINGS

Recent studies confirm that the incidence of anaphylaxis, particularly food-induced anaphylaxis, is increasing world-wide. The rise in anaphylaxis incidence appears most pronounced in children under the age of 5 years, which is also the age group most at risk of hospitalization for food-induced anaphylaxis. Identification of factors that may increase the risk of episodes of anaphylaxis remains an important research priority. Recently, two large cohort studies using data from electronic medical records confirmed that individuals with asthma are at higher risk of anaphylaxis and those with severe asthma have the highest risk of all. With respect to modifiable lifestyle factors, several studies have demonstrated a link between latitude and anaphylaxis, with areas with less year-round sunlight reporting a higher prevalence of food-induced anaphylaxis.

SUMMARY

Reports of an increasing incidence of anaphylaxis internationally highlight the need for identification of modifiable risk factors for anaphylaxis. Emerging evidence suggests that low vitamin D levels may be associated with risk of anaphylaxis and food allergy; however, further studies are required to confirm this.

Epidemiology and risk factors for drug allergy

The aim of this review was to describe the current evidence-based knowledge of the epidemiology, prevalence, incidence, risk factors and genetic associations of drug allergy. Articles published between 1966 and 2010 were identified in MEDLINE using the key words adult, adverse drug reaction reporting systems, age factors, anaphylactoid, anaphylaxis, anaesthetics, antibiotics, child, drug allergy, drug eruptions, ethnic groups, hypersensitivity, neuromuscular depolarizing agents, neuromuscular nondepolarizing agents, sex factors, Stevens Johnson syndrome and toxic epidermal necrolysis. Additional studies were identified from article reference lists. Relevant, peer-reviewed original research articles, case series and reviews were considered for review. Current epidemiological studies on adverse drug reactions (ADRs) have used different definitions for ADR-related terminology, often do not differentiate immunologically and non-immunologically mediated drug hypersensitivity, study different study populations (different ethnicities, inpatients or outpatients, adults or children), utilize different methodologies (spontaneous vs. non-spontaneous reporting, cohort vs. case-control studies), different methods of assessing drug imputability and different methods of data analyses. Potentially life-threatening severe cutaneous adverse reactions (SCAR) are associated with a high risk of morbidity and mortality. HLA associations for SCAR associated with allopurinol, carbamazepine and abacavir have been reported with the potential for clinical use in screening prior to prescription. Identification of risk factors for drug allergy and appropriate genetic screening of at-risk ethnic groups may improve the outcomes of drug-specific SCAR. Research and collaboration are necessary for the generation of clinically-relevant, translational pharmacoepidemiological and pharmacogenomic knowledge, and success of health outcomes research and policies on drug allergies.

Usefulness of post mortem determination of serum tryptase, histamine and diamine oxidase in the diagnosis of fatal anaphylaxis

The diagnosis of fatal anaphylaxis can be difficult for clinical features may not always be evident in necropsy. Therefore post mortem determination of tryptase and other blood parameters can be helpful in verifying the diagnosis. We compared post mortem tryptase, histamine and diamine oxidase (DAO) serum levels of two patients who had died after a Hymenoptera sting and one patient who died of bronchospasm during anaesthesia with data obtained from 55 control subjects who had died from other causes than anaphylaxis. In the three anaphylactic cases, serum tryptase level was 880, 68 and 200 μg/l (normal range in living subjects: <11.4 μg/l), histamine was 37.5, 8.5 and 23.2 ng/ml (normal range: <0.3 ng/ml) and DAO was 1, 30 and 4 U/ml (normal range 10-30 U/ml), respectively. Values in the control group were as follows: tryptase 1-340 μg/l (mean 24.2 ± 58.2), histamine 5.0-22.0 ng/ml (mean 14.7 ± 3.9) and DAO 0-114 U/ml (mean 21.1 ± 27.8). 19/55 (34.5%) of the controls had elevated tryptase levels >11.4 μg/l, with four of them showing values >45 μg/ml. Significantly higher histamine levels were seen in blood samples taken more than 24h post mortem (p<0.05), whereas the timing of blood collection had no effect on tryptase and DAO levels. While moderately elevated tryptase levels are common in post mortem sera, values above 45 μg/l may support the diagnosis of fatal anaphylaxis. Strongly elevated histamine levels might give an additional clue on fatal anaphylaxis, whereas DAO does not seem to be helpful.

Recognition and management of food-induced anaphylaxis

Food-induced anaphylactic reactions are common and increasing in frequency. Despite the existence of a consensus definition of anaphylaxis, many cases are missed, recommended treatments are not given, and follow-up is inadequate. New aspects of its pathophysiology and causes, including atypical food-induced causes, are still being uncovered. Epinephrine remains the cornerstone for successfully treating anaphylaxis; H1 and H2 antihistamines, glucocorticoids, and β-agonists are ancillary medications that may be used in addition to epinephrine. Early recognition of anaphylaxis, appropriate emergency treatment, and follow up, including prescription of self-injectable epinephrine, are essential to prevent death and significant morbidity from anaphylaxis.

Successful treatment of acute systemic anaphylaxis in a western lowland gorilla (Gorilla gorilla gorilla)

This brief communication describes the successful treatment of acute systemic anaphylaxis in a wild-born but captive infant western lowland gorilla (Gorilla gorilla gorilla) in the Republic of Congo. The infant demonstrated signs of acute respiratory distress, lingual swelling, and reaction to intradermal tuberculin, given 55 hr earlier. Details of the treatment with steroids, anesthetic induction, and i.v. epinephrine are all reported, and potential antigens that may have initiated the anaphylactic shock are discussed.

Allergies in Asia: differences in prevalence and management compared with western populations

There is wide variability in the epidemiology and management of childhood asthma and related atopic diseases globally. Urbanized, affluent Western countries tend to have a higher prevalence of these diseases compared with Asian nations. However, recent studies have shown that the prevalence in Asia is increasing, although the rate of increase has slowed in the more developed Asian cities. Some possible causes for these differences are socioeconomic status, degree of urbanization, rates of infection, healthcare practices and genetic factors. Importantly, there are significant differences in the way asthma and allergic diseases are managed within Asia. This is of great concern because of the health implications, as these diseases are some of the most common chronic conditions that affect both adults and children. This review compares the differences in prevalence and management between Asia and the West, and discusses some of the possible reasons behind these variations.

Post-mortem diagnosis of anaphylaxis: A difficult task in forensic medicine

The lack of reliable laboratory biomarkers and common standard definitions of signs and symptoms represents the main problem for clinicians when a suspected anaphylactic event must be diagnosed, while a post-mortem diagnosis of anaphylaxis is often a very difficult task in forensic medicine. Significant necroscopic signs as well as the data reported from witnesses or medical records may be absent, biological fluids as blood or urine may be unavailable or under thanatological modifications. The aim of this review is to focus on the diagnostic difficulties with which coroners and forensic pathologists have to cope when a confirmation of anaphylactic death is required by judicial authorities. Investigation methods for a prudent forensic diagnosis of anaphylactic death as well as the need of new potential laboratory or histological investigation techniques coming from immunological research are discussed too.

Postmortem findings after anaphylactic reactions to drugs in Turkey

AIMS

To determine the frequency of anaphylactic deaths at autopsies performed in Turkey between January 2001 and June 2006 and to review the circumstances of death and autopsy findings.

METHODS

The Council of Forensic Medicine database in Istanbul was searched for anaphylactic deaths. Postmortem reports and medical records were reviewed to determine the circumstances of death. Data about basic demographics, medical history, drugs responsible for allergic reactions, and pathologic findings at autopsy were collected.

RESULTS

A total of 36 anaphylactic deaths from drugs were identified for the study period. Death was due to antibiotics in 26 cases, analgesics in 7 cases, an intraoperative drug in 1 case, an H2 receptor in 1 case, and intravenous contrast medium in 1 case. Out of 36 cases, 19 were male and 17 female. They were aged between 1 and 74 years with the median age of 26.7 years. Death occurred within 1 hour of the onset of anaphylaxis in 27 cases. Findings at autopsy included nonspecific pulmonary edema and congestion, upper airway edema, cerebral hypoxia, and cutaneous edema. Serum tryptase levels were not measured in all cases.

CONCLUSION

Anaphylactic reaction is an uncommon cause of sudden death. In many cases, no specific macroscopic or microscopic findings were detected at autopsy. When serum tryptase levels cannot be determined, in the presence of typical clinical records, eye witness reports and autopsy findings can be useful diagnostic aids.

Epidemiology of anaphylaxis

PURPOSE OF REVIEW

The prevalence of allergic disorders has more than doubled in the last two decades leading to increased community concern and anxiety, and unprecedented demand for allergy-specialist services. However, although allergic reactions are common, anaphylaxis is uncommon and fatal anaphylaxis is rare. This review examines recent developments in the epidemiology of anaphylaxis, focusing on new information that may assist in identifying those at increased risk of severe reactions and adverse outcomes.

RECENT FINDINGS

Recent studies suggest an increase in prevalence of anaphylaxis in industrialized countries. Examination of the demographic characteristics of anaphylaxis has revealed potential approaches to better recognize those at greatest risk. Novel laboratory approaches to identify patients at increased risk of severe reactions have been suggested.

SUMMARY

Increased knowledge of the epidemiology of anaphylaxis has provided insights into the characteristics of those patient groups most at risk of adverse outcomes. However, these characteristics have poor specificity and limited applicability for detection of at-risk individuals in the clinical setting. Further research is required to facilitate more accurate assessment of an individual's risk for anaphylaxis or fatal outcome. This would represent a major advance in clinical management and enable better allocation of existing healthcare resources.

Sudden adult death

In the investigation of sudden death in adults, channelopathies, such as long QT syndrome, have risen to the fore in the minds of forensic pathologists in recent years. Examples of these disorders are touched upon in this review as an absence of abnormal findings at postmortem examination is characteristic and the importance of considering the diagnosis lies in the heritable nature of these conditions. Typically, a diagnosis of a possible channelopathy is evoked as an explanation for a 'negative autopsy' in a case of apparent sudden natural death. However, the one potential adverse effect of this approach is that subtle causes of sudden death may be overlooked. The intention of this article is to review and discuss potential causes of sudden adult death (mostly natural) that should be considered before resorting to a diagnosis of possible channelopathy. Nonetheless, it becomes apparent that many of the potential causes of sudden death can have a genetic basis. Thus, it becomes an important consideration that there may be a genetic basis to sudden death that extends beyond the negative autopsy.

Anaphylactic deaths in Maryland (United States) and Shanghai (China): a review of forensic autopsy cases from 2004 to 2006

Anaphylaxis is a life threatening allergic reaction that is rapid in onset and may cause sudden death. A retrospective study was performed using the database from the Office of the Chief Medical Examiner (OCME) in the State of Maryland and the Department of Forensic Medicine in Shanghai Medical College (DFM-SMC) to examine the etiology and forensic investigation findings of anaphylactic deaths from 2004 to 2006. Details of the medical history, agent responsible for the allergic reaction, death scene investigation and postmortem examination findings were reviewed for all cases. A total of 28 cases of anaphylactic death were identified for the study period, 17 from Maryland and 11 from Shanghai. Of the 17 Maryland cases, 6 (35%) involved allergic reaction to food, 5 (25%) to drugs, 2 to bee stings, 1 to hair dye, and 3 to unknown allergens. Investigation revealed that 9 of 17 cases had a history of asthma and 8 had previous allergic reactions to certain foods and / or drugs. In Shanghai, all 11 deaths resulted from anaphylactic reaction to antibiotics, 10 of which occurred in clinics illegally operated by unlicensed physicians. The interval between the onset of symptoms and death ranged from less than 1 min to 3 days after initially contacting the allergen. In the majority (68%) of cases, death occurred within 8h after the onset of symptoms. Postmortem findings were relatively non-specific, and included pharyngeal/laryngeal edema 14/28 (50%), mucus plugging in the airways 11/28 (39%), and pulmonary congestion and edema 28/28 (100%). Serum tryptase concentrations were measured in 14 cases in Maryland and the concentration ranged from 3.3 ng/ml to 200 ng/ml. There were significant differences with regards to allergen type and the circumstances of death between these two regions. Inappropriate use of antibiotics and illegal medical practices were the main causes of identified anaphylactic death in Shanghai. In Maryland anaphylactic deaths were mainly caused by food reactions. This study indicates that the postmortem diagnosis of anaphylactic death is usually based on exclusion and circumstantial evidence. Knowledge of the patient's history and circumstances of death is of major importance for the forensic pathologist when investigating suspected anaphylactic death.

Sudden death by laryngeal polyp: a case report and review of the literature

Sudden unexpected death in the context of bizarre or unusual behavior usually relates to acute drug intoxication or excited delirium. We report the case of a man who died suddenly while running naked on a public street. Although the initial death investigation was indicative of excited delirium or drug intoxication, autopsy revealed glottic obstruction by an inflammatory laryngeal polyp. Toxicologic studies were negative and investigation revealed presentation at a hospital the day before death with stridor. It is believed he developed airway obstruction while dressing at home and ran out on the street to find assistance. This case illustrates the importance of a thorough death investigation and a broad differential diagnosis when approaching a forensic autopsy.