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.

A Specialized Therapeutic Approach to Chronic Urticaria Refractory to H1-Antihistamines Improves Disease Burden: The Spanish AWARE Experience.

OBJECTIVE: During its first year, the AWARE study assessed disease activity, patient quality of life (QOL), and treatment patterns in chronic urticaria (CU) refractory to H1-antihistamines (H1-AH) in clinical practice. METHODS: We performed an observational, prospective (24 months), international, multicenter study. The inclusion criteria were age ≥18 years and H1-AH-refractory CU (>2 months). At each visit, patients completed questionnaires to assess disease burden (Urticaria Control Test [UCT]), disease activity (7 day-Urticaria Activity Score [UAS7]), and QOL (Dermatology Life Quality index [DLQI], Chronic Urticaria Quality of Life Questionnaire [CU-Q2oL], and Angioedema Quality of Life Questionnaire [AE-QoL]). We present data for Spain. RESULTS: The study population comprised 270 evaluable patients (73.3% female, mean [SD] age, 48.9 [14.7] years). At baseline, 89.3% were prescribed a CU treatment. After 1 year, first- and second-line treatments became less frequent and third-line treatments became more frequent. At baseline, 47.0% of patients experienced angioedema; at 1 year, this percentage had fallen to 11.8%. The mean (SD) AE-QoL score decreased from 45.2 (28.7) to 24.0 (25.8). The mean (SD) UCT score decreased from 7.0 (4.5) to 12.1 (4.1). According to UAS7, 38.2% of patients reported absence of wheals and itch in the previous 7 days at 1 year compared with 8.3% at baseline. The mean (SD) DLQI score decreased from 8.0 (7.4) to 2.8 (4.6). At the 1-year visit, the percentage of patients reporting a high or very high impact on QOL fell from 29.9% to 9.6%. CONCLUSION: H1-AH-refractory CU in Spain is characterized by absence of control of symptoms and a considerable impact on QOL. Continuous follow-up of CU patients and third-line therapies reduce disease burden and improve patients' QOL.

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.

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.

Increased incidence of admissions for anaphylaxis in Spain 1998-2011.

We report on trends in anaphylaxis admissions in the Spanish hospital system during the period 1998-2011. Data on admissions for anaphylaxis were obtained from the Spanish Information System for Hospital Data for the period 1998-2011. Patients were selected using the codes for anaphylaxis in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Poisson regression models were used to estimate incidence rate ratios. We recorded a 1.89-fold increase in admissions for anaphylaxis in Spanish hospitals during the study period, particularly in patients aged 0-14 years (1.65- to 3.22-fold until 2009 and 4.09- to 12.59-fold until 2011) and in food anaphylaxis in all age groups (2.78-fold until 2009 and 8.74-fold until 2011). The incidence of anaphylaxis is perceived as having increased in recent years, especially anaphylaxis caused by food and anaphylaxis affecting the pediatric population.

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.

A Specialized Therapeutic Approach to Chronic Urticaria Refractory to H1-Antihistamines Improves Disease Burden: The Spanish AWARE Experience

Objective: During its first year, the AWARE study assessed disease activity, patient quality of life (QOL), and treatment patterns in chronic urticaria (CU) refractory to H1-antihistamines (H1-AH) in clinical practice.Methods: We performed an observational, prospective (24 months), international, multicenter study. The inclusion criteria were age ≥18 years and H1-AH–refractory CU (>2 months). At each visit, patients completed questionnaires to assess disease burden (Urticaria Control Test [UCT]), disease activity (7 day-Urticaria Activity Score [UAS7]), and QOL (Dermatology Life Quality index [DLQI], Chronic Urticaria Quality of Life Questionnaire [CU-Q2oL], and Angioedema Quality of Life Questionnaire [AE-QoL]). We present data for Spain.Results: The study population comprised 270 evaluable patients (73.3% female, mean [SD] age, 48.9 [14.7] years). At baseline, 89.3% were prescribed a CU treatment. After 1 year, first- and second-line treatments became less frequent and third-line treatments became more frequent. At baseline, 47.0% of patients experienced angioedema; at 1 year, this percentage had fallen to 11.8%. The mean (SD) AE-QoL score decreased from 45.2 (28.7) to 24.0 (25.8). The mean (SD) UCT score decreased from 7.0 (4.5) to 12.1 (4.1). According to UAS7, 38.2% of patients reported absence of wheals and itch in the previous 7 days at 1 year compared with 8.3% at baseline. The mean (SD) DLQI score decreased from 8.0 (7.4) to 2.8 (4.6). At the 1-year visit, the percentage of patients reporting a high or very high impact on QOL fell from 29.9% to 9.6%.Conclusions: H1-AH–refractory CU in Spain is characterized by absence of symptoms and a considerable impact on QOL. Continuous follow-up of CU patients and third-line therapies reduce disease burden and improve patients’ QOL (AU)

Objetivo: El estudio AWARE evalúa la actividad de la enfermedad, la calidad de vida (CV) del paciente y los patrones de tratamientoen pacientes con urticaria crónica (UC) refractarios a antihistamínicos H1 (AH-H1) en práctica clínica durante el primer año del estudio.Métodos: Estudio observacional, prospectivo (24 meses), internacional y multicéntrico. Pacientes ≥18 años con diagnóstico de UC refractariosa AH-H1 (>2 meses). En cada visita, los pacientes completaron cuestionarios para evaluar la carga de la enfermedad (Urticaria Control Test[UCT]), actividad de la enfermedad (7 day-Urticaria Activity Score [UAS7]), CV (Dermatology Life Quality index [DLQI], Chronic UrticariaQuality of Life Questionnaire [CU-Q2oL], Angioedema Quality of Life [AE-QOL]). Presentamos datos españoles.Resultados: Se incluyeron 270 pacientes evaluables (73,3% mujeres, edad media [DE] 48,9 [14,7] años). Al inicio del estudio, al 89,3%se le prescribió un tratamiento para la UC. Después de 1 año, los tratamientos de primera/segunda línea tendieron a disminuir y la tercera línea a aumentar. El 47,0% de los pacientes experimentaron angioedema al inicio del estudio, siendo del 11,8% al cabo de 1 año. Lamedia (DE) de AE-QOL pasó de 45,2 (28,7) a 24,0 (25,8). La media (DE) de UCT pasó de 7,0 (4,5) a 12,1 (4,1). Según UAS7, el 38,2% depacientes reportaron ausencia de ronchas y prurito en los últimos 7 días al año frente al 8,3% al inicio. El DLQI medio (DE) pasó de 8,0 (7,4)a 2,8 (4,6). En la visita de 1 año, el porcentaje de pacientes que reportaron un impacto en la CV alto/muy alto pasó del 29,9% al 9,6%.Conclusiones: Los pacientes españoles con UC refractarios a AH-H1 presentan una falta de control de la sintomatología con un importanteimpacto en su CV. El seguimiento continuo de los pacientes con urticaria crónica espontánea y las terapias de tercera línea han demostradouna tendencia a reducir la carga de la enfermedad y a mejorar la CV de los pacientes (AU)

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 (AU)

Antecedentes: La muerte por anafilaxia es un evento muy excepcional, con una incidencia que varía de 0,5 a 1 muerte por millón de personas/año. Objetivo: Usando las técnicas de una revisión sistemática, nuestro objetivo ha sido explicar las diferencias en la incidencia informada de la muerte por anafilaxia atendiendo a diversos factores metodológicos y demográficos empleados en los diversos estudios de la revisión. Métodos: Se realizaron búsquedas en PubMed/MEDLINE, EMBASE y Web of Science, con el fin de obtener estudios de cohortes y registros prospectivos y retrospectivos relevantes que hubieran evaluado la tasa de muerte por anafilaxia en la población de un país o una región administrativa. La estrategia de investigación se basó en combinar “anafilaxia” con “muerte”, “diseño del estudio” y “resultados principales” (incidencia). Resultados: Un total de 46 estudios cumplieron con los criterios del estudio. Los estudios incluyeron 16.541 muertes. El rango de la tasa de mortalidad por anafilaxia para todas las causas de anafilaxia fue de 0,002 a 2,51 muertes por millón de personas/año. La anafilaxia mortal debida a los alimentos (rango 0,002-0,29) fue más rara que las muertes debidas a medicamentos (rango 0,004-0,56) o veneno de himenópteros (rango 0,02-0,61). La frecuencia de muertes por anafilaxia por fármacos aumentó durante el período de estudio (IRR por año, 1,02; IC del 95%: 1,00-1,04). Se detectó una heterogeneidad considerable en casi todos los metaanálisis realizados. Conclusión: La incidencia de anafilaxia mortal es muy baja y difiere según los distintos subgrupos analizados. Los estudios fueron muy heterogéneos. La muerte por anafilaxia debida a alimentos parece ser menos común que la anafilaxia mortal debida a fármacos o por veneno de himenópteros (AU)

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

Background: 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 thatcompared 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 ofanaphylaxis (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 (adjustedand nonadjusted), COPD increased the severity of anaphylaxis (OR, 2.47; 95%CI, 1.46-4.18). In the case of asthma studies, only 1 studyassessed 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 notusually assess the importance of severity of asthma.(AU)

Antecedentes: El asma es muy frecuente en todos los grados de gravedad de la anafilaxia y así mismo el asma y la enfermedad pulmonarobstructiva crónica (EPOC) se han asociado con las anafilaxias graves.Objetivo: Realizamos una revisión sistemática y un meta-análisis para evaluar la influencia de las enfermedades respiratorias en lagravedad de la anafilaxia.Métodos: Se realizaron búsquedas en PubMed / MEDLINE, EMBASE y Web of Science de estudios observacionales, en donde se compararonla gravedad de la anafilaxia entre pacientes que tenían o no enfermedades respiratorias.Resultados: Un total de 13 estudios evaluaron la influencia de las enfermedades respiratorias en la gravedad de la anafilaxia. La enfermedadrespiratoria aumentó la gravedad de la anafilaxia (OR, 1,87; IC 95%, 1,30-2,70). En general, el asma también aumentó la gravedad dela anafilaxia (OR, 1,89; IC del 95%, 1,26-2,83). En el meta-análisis de todos los estudios con EPOC (ajustado y no ajustado), la mismaaumentó la gravedad de la anafilaxia (OR, 2,47; IC del 95%, 1,46-4,18). En los estudios con asma, solo uno evaluó la influencia de lagravedad del asma en la gravedad de la anafilaxia.Conclusiones: La evidencia que muestra que la enfermedad respiratoria aumenta la gravedad de la anafilaxia es baja a moderada, aunquelos estudios no suelen evaluar la importancia de la gravedad del asma.(AU)

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.

Clinical and functional differences among patients with idiopathic anaphylaxis.

BACKGROUND: There are no studies assesing whether patients with idiopathic anaphylaxis are a heterogenous population OBJECTIVE: A study has been carried out to assess whether clinical and functional differences (mast cell releasability) exist between two sub-types of Idiopathic Anaphylaxis (Generalized Idiopathic Anaphylaxis -IA-G- and Idiopathic Anaphylaxis with Angioedema -IA-A-). METHODS: Patients were selected from the Idiopathic Anaphylaxis (IA) patient population of Hospital General de Albacete (Albacete, Spain) and this data were collected between 1990 and 1995. This series is composed of 81 patients. In the interest of seeing whether an IA classification is warranted between IA-G and IA-A, a logistic regression model was constructed in order to know if differences exist between IA-G and IA-A. To evaluate mast cell releaseability in different groups (IA-G, IA-A, atopic patients, urticaria and healthy subjects) we analysed the log 10 wheal area produced by four consecutive concentrations of codeine (from 90 to 3,3 mg/ ml). In those patients with IA-G, the variable urticaria was controlled, but not in those with IA-A. A parallel line assay was used to study the differences arising among all groups. When the conditions of parallelism and linearity were not fulfilled, a Hotelling's T2 test was performed. RESULTS: In the logistic regression equation total IgE, with an O.R. of 1.006 (95% C.I. 1.001-1.01) favoured the presence of IA-G; whereas the presence of urticaria did not favour the presence of IA-G, with an O.R. of 0.159 (95% C.I. 0.04-0.507). IA-G and IA-A patients showed a higher cutaneous reaction to codeine than atopic patients (p=0.005 and p=0.001 respectively). However, IA-G patients had a lower reaction to codeine than those patients with urticaria (p=0.048). No differences were observed among patients with IA-A and patients with urticaria, as was the case between IA-A and IA-G patients with respect to cutaneous response to codeine. CONCLUSION: Apparently, IA-G patients appear to be closely related to the presence of atopy, while IA-A patients are closely related to the presence of urticaria. Along with other unknown factors, an enhanced mast cell releaseability may explain these episodes of Idiopathic Anaphylaxis among atopic patients.