How Far Are We From Achieving Delabeling of False Penicillin/ß-Lactam Allergy Alerts? A Population Problem.

BACKGROUND: Interest in finding efficient ways to remove penicillin allergy alerts has grown as a result of awareness of the considerable excess of false-negative diagnoses in patients with penicillin allergy labels (90%-95%), the poorer course with non-ß-lactam antibiotics, the increase in bacterial resistance, and the fact that these problems can affect up to 20% of the population in some countries. The strategies proposed have generated many publications in countries where the number of allergists to conduct such studies is low. In many cases where delabeling is performed, the risk of ß-lactam allergy is low, and a single penicillin challenge is sufficient to delabel the alert. However, other less "ultrarapid" strategies can be used to administer a ß-lactam during an admission for infection and thus postpone delabeling until traditional drug allergy consultations. However, the definitive withdrawal of ß-lactam alerts is threatened by nonremoval of alerts in electronic health records and by the reactivation or nonsynchronization of alerts between electronic systems at different levels of care. Allergy departments need to reflect on how to implement practices that enable rapid and efficient delabeling of drug allergy alerts, especially in patients with major comorbidities.

Incidence of Fatal Anaphylaxis: A Systematic Review of Observational Studies.

BACKGROUND: Fatal anaphylaxis is very rare, with an incidence ranging from 0.5 to 1 deaths per million person-years. OBJECTIVE: Based on a systematic review, we aimed to explain differences in the reported incidence of fatal anaphylaxis based on the methodological and demographic factors addressed in the various studies. METHODS: We searched PubMed/MEDLINE, EMBASE, and the Web of Science for relevant retrospective and prospective cohort studies and registry studies that had assessed the anaphylaxis mortality rate for the population of a country or for an administrative region. The research strategy was based on combining the term "anaphylaxis" with "death", "study design", and "main outcomes" (incidence). RESULTS: A total of 46 studies met the study criteria and included 16,541 deaths. The range of the anaphylaxis mortality rate for all causes of anaphylaxis was 0.002-2.51 deaths per million person-years. Fatal anaphylaxis due to food (range 0.002-0.29) was rarer than deaths due to drugs (range 0.004-0.56) or Hymenoptera venom (range 0.02-0.61). The frequency of deaths due to anaphylaxis by drugs increased during the study period (IRR per year, 1.02; 95%CI, 1.00-1.04). We detected considerable heterogeneity in almost all of the meta-analyses carried out. CONCLUSION: The incidence of fatal anaphylaxis is very low and differs according to the various subgroups analyzed. The studies were very heterogeneous. Fatal anaphylaxis due to food seems to be less common than fatal anaphylaxis due to drugs or Hymenoptera venom.

Association Between Severity of Anaphylaxis and Co-occurrence of Respiratory Diseases: A Systematic Review and Meta-analysis of Observational Studies.

BACKGROUND AND OBJECTIVE: Asthma is very prevalent in all grades of severity of anaphylaxis. Asthma and chronic obstructive pulmonary disease (COPD) have been associated with the severity of anaphylaxis. Objective: We carried out a systematic review and meta-analysis to assess the influence of respiratory diseases on the severity of anaphylaxis. METHODS: We searched PubMed/MEDLINE, EMBASE, and the Web of Science for observational studies. The target studies were those that compared the severity of anaphylaxis between patients who had or did not have respiratory diseases. RESULTS: A total of 13 studies assessed the severity of anaphylaxis in respiratory disease. Respiratory disease increased the severity of anaphylaxis (OR, 1.87; 95%CI, 1.30-2.70), as did asthma (OR, 1.89; 95%CI, 1.26-2.83). For the meta-analysis of all studies (adjusted and nonadjusted), COPD increased the severity of anaphylaxis (OR, 2.47; 95%CI, 1.46-4.18). In the case of asthma studies, only 1 study assessed the influence of severity of asthma on severity of anaphylaxis. CONCLUSIONS: Evidence showing that respiratory disease increases the severity of anaphylaxis is low to moderate, although studies do not usually assess the importance of severity of asthma.

Clinical Profile of Patients With Severe Anaphylaxis Hospitalized in the Spanish Hospital System: 1997-2011.

BACKGROUND AND OBJECTIVE: Studies assessing the severity of anaphylaxis lack a comprehensive approach to collecting data on comorbidities that may worsen prognosis. Objective: Using the Elixhauser score (a systematic index associated with longer stay, hospital charges, and mortality), we determined which comorbidities were associated with more severe anaphylaxis. METHODS: We based our study on the Spanish Ministry of Health database of hospital discharges in Spain between 1997 and 2011. We constructed logistic regression models in which the dependent variables were outcomes related to greater severity (death, cardiac arrest, need for invasive mechanical ventilation or vasopressor drugs, admission to the intensive care unit, and length of stay) and the independent variables were the 30 comorbidities that comprise the Elixhauser score, age, sex, and main causes of anaphylaxis. RESULTS: We found that a higher risk of severe anaphylaxis was associated (3 or more logistic regressions) with age >50 years or having experienced cardiac arrhythmia, coagulation disorder, associated fluid-electrolyte imbalance, chronic pulmonary disease, or Echinococcus anaphylaxis. Likewise, in the adjusted analysis, a higher Elixhauser score was associated with most of the outcomes analyzed for severity of anaphylaxis. CONCLUSIONS: Cardiovascular and respiratory diseases increase the severity of anaphylaxis, and the resulting poor health status (represented as a higher Elixhauser score) is associated with more severe anaphylaxis.

Clinical Practice Guidelines for Diagnosis and Management of Hypersensitivity Reactions to Contrast Media.

The objective of these guidelines is to ensure efficient and effective clinical practice. The panel of experts who produced this consensus document developed a research protocol based on a review of the literature. The prevalence of allergic reactions to iodinated contrast media (ICM) is estimated to be 1:170 000, that is, 0.05%-0.1% of patients undergoing radiologic studies with ICM (more than 75 million examinations per year worldwide). Hypersensitivity reactions can appear within the first hour after administration (immediate reactions) or from more than 1 hour to several days after administration (nonimmediate or delayed reactions). The risk factors for immediate reactions include poorly controlled bronchial asthma, concomitant medication (eg, angiotensin-converting enzyme inhibitors, ß-blockers, and proton-pump inhibitors), rapid administration of the ICM, mastocytosis, autoimmune diseases, and viral infections. The most common symptoms of immediate reactions are erythema and urticaria with or without angioedema, which appear in more than 70% of patients. Maculopapular rash is the most common skin feature of nonimmediate reactions (30%-90%). Skin and in vitro tests should be performed for diagnosis of both immediate and nonimmediate reactions. The ICM to be administered will therefore be chosen depending on the results of these tests, the ICM that induced the reaction (when known), the severity of the reaction, the availability of alternative ICM, and the information available on potential ICM cross-reactivity. Another type of contrast media, gadolinium derivatives, is used used for magnetic resonance imaging. Although rare, IgE-mediated reactions to gadolinium derivatives have been reported.

Self-Management of Anaphylaxis Is Not Optimal.

BACKGROUND: Our objective was to ascertain the degree of adherence to recommendations made to patients with anaphylaxis, most of whom were attended in our allergy outpatient clinic. METHODS: A questionnaire was sent to 1512 patients who had experienced anaphylaxis and completed by 887. The chosen definition of anaphylaxis was that of the National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network Symposium. We evaluated the prescription, purchase, and use of epinephrine auto-injectors and oral drugs, as well as the avoidance of allergens involved in previous anaphylaxis episodes. RESULTS: Most patients (94.53%) reported that they had received advice on avoidance of responsible allergens after their allergy workup. Epinephrine auto-injectors and oral drugs were prescribed according to the subtype of anaphylaxis. Only 30.74% of patients used the epinephrine auto-injector; 54.26% took oral medication. Most patients (88.3%) avoided the allergen. CONCLUSIONS: Despite general agreement that anaphylaxis occurring in the community should be treated with epinephrine auto-injectors, use of these devices to treat recurrences was low in our patients. Oral medication intake was more common than the epinephrine auto-injector in all subtypes. In order to increase adherence to epinephrine auto-injectors, it is necessary to think beyond the measures recommended during regular visits to allergy outpatient clinics.

Incidence of anaphylaxis in the city of Alcorcon (Spain): a population-based study.

BACKGROUND: Relatively few studies have examined the incidence of anaphylaxis in the general population. OBJECTIVE: To report the incidence of anaphylaxis among the general population of the city of Alcorcon, Spain, using various public health care databases. METHODS: Episodes of anaphylaxis were recovered using validated alphanumeric strings in different fields of electronic clinical records used in the different public health settings in the city of Alcorcon (primary care, Emergency Department, hospitalized patients and Allergy Outpatient Clinic). Patients with anaphylaxis were tracked across the different clinical settings in Alcorcon. RESULTS: The incidence of anaphylaxis in Alcorcon was 103.37 episodes per 100 000 person-years (total standardized incidence rate of 112.2). There was a peak of 313.58 episodes in the 0-4 years age group and a different distribution of incidence rates (although non-significant) among different age groups between male patients and female patients. In most age groups, incidence tended to be higher for female patients aged over 10 years. Patients were attended at two or more levels in 76.78% of episodes, and a new evaluation was often made at a primary care centre (71.43%), Allergy Outpatient Clinic (75.6%), or both after the episode (58.93%). CONCLUSION AND CLINICAL RELEVANCE: This study revealed a higher rate of anaphylaxis than that in previous studies, although this incidence rate is probably lower than the real incidence rate. Studies exploring potential methodological, genetic and environmental factors accounting for these higher rates of anaphylaxis are required.

Incidence of anaphylaxis and subtypes of anaphylaxis in a general hospital emergency department.

BACKGROUND: The absence of large-scale international studies means that data on anaphylaxis in emergency departments in different geographic areas are still necessary. OBJECTIVE: To determine the incidence of anaphylaxis and subtypes of anaphylaxis and their distribution by age group in the emergency department of Hospital Universitario Fundación Alcorcon, Alcorcon (Madrid), Spain. METHODS: Our study was performed between 2004 and 2005. We used the definition of anaphylaxis established by the NIAID-FAAN Symposium. Patient information was collected from the electronic clinical records of the emergency department using alphanumeric strings to identify acute allergic illnesses. This strategy recovered 91.7% of all anaphylaxis episodes in a pilot study. RESULTS: We observed a crude cumulative incidence of 0.9 episodes of anaphylaxis per 1000 emergency episodes (95% confidence interval [CI], 0.8-1.1), and 0.8 episodes per 1000 people (95% CI, 0.7-0.9). Standardized cumulative incidence of anaphylaxis according to the Standardized European Population was 1.1 (95% CI, 0.9-1.2). On analyzing the 213 cases of anaphylaxis, we discovered that the main cause was food (28.6%), followed by drugs (28.2%), unknown causes (27.2%), Anisakis (10.8%), Hymenoptera venom (3.3%), exercise (2.4%), and latex (0.9%). Food-induced anaphylaxis was less frequent in all groups older than the 0-4 age group in both reference populations (people who attend the emergency department and the general population). CONCLUSIONS: The cumulative incidence of anaphylaxis in our emergency department is low. Anaphylaxis by foods is more frequent in the 0-4 year group than in the other age groups. Drugs and food are the most frequent causes of anaphylaxis in our emergency department.

Thrombocytopenia and anaphylaxis secondary to heparin in a hemodialysis patient.

AIMS: We describe a rare case of anaphylaxis and thrombocytopenia whose cause was heparin used during hemodialysis sessions. CASE REPORT: A 77-year-old woman suffered five consecutive episodes of vomiting, tachypnea, wheezing or rales, immediately after initiating hemodialysis. In the first of these episodes, arterial pressure was undetectable. In all of the episodes there was evidence of the presence of hypoxia (always below 60 mmHg) and thrombocytopenia (always below l00,000/microl,, with partial platelets recovery among episodes. The episodes started immediately after hemodialysis sessions and heparin infusion; either sodium heparin or enoxaparin was used. Utilization of different filters was not able to stop the episodes. These were stopped when a switch from heparin to hirudin was tested. Tryptase levels, as a marker of mast cells activation and anaphylaxis, were not increased in two of the episodes which were assessed. IgG antibodies against heparin-PF4 complex was detected at high levels. DISCUSSION: A diagnosis of concomitant anaphylaxis and thrombocytopenia caused by sodium heparin and a low-molecular weight heparin (enoxaparin) were assumed.