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Biomedical Research

Anaphylactic patient characteristics, clinical features, and current practice in the Emergency Unit

Author(s): Shirina Alsowaidi, Amna Al Hana, Khalid M. Zarouni, Ahmed H. Al Zaabi

Vol. 21, No. 4 (2010-10 - 2010-12)

Shirina Alsowaidi1, Amna Al Hana2, Khalid M. Zarouni1, Ahmed H. Al Zaabi1, Abdishakur Abdulle1

(1) Department of Internal Medicine, Faculty of Medicine, UAE University;
(2) Tawam Hopkin’s Hospital, Al-Ain, United Arab Emirates.

Abstract

We aim to assess patient characteristics, clinical features, and the current practice in the management of anaphylaxis. We conducted a retrospective review of anaphylactic patients among emergency department visitors from January, 2007 to January 2008, in Tawam hospital, Al-Ain, United Arab Emirates (UAE). Data pertaining patient’s age, sex, clinical features, involved systems, past history of allergy, type of the allergen, treatment and outcome (death, discharge, re-admission, and follow up) was collected in a two page questionnaire. A total number of 123 patient charts were reviewed. Overall, 69.1% subjects had a known history of allergic disease out of which only 31.8% of the subjects (males and females) were aware of the nature of their allergic disease and the triggering allergen. Regarding the current episode of anaphylaxis, most of patients (98 ) and regardless of their history, reported knowledge of the triggering allergen, the overwhelming majority (77) of whom were exposed to hymenoptera (ants, wasps, and bees). Although unexpected, a considerable number of cases (21.1%) were said to have been exposed to scorpion bites. The reported symptoms and the severity of cases varied from simple itching to significant involvement of the cardiovascular system. Most of the subjects were transported to hospital by a family member as opposed to the existing ambulance services. Overall, antihistamines and oral steroids, but not adrenalin, were the treatments of choice. No prolonged hospitalization was recorded as all patients were, presumably, treated satisfactorily and discharged on the same the day. The current study reports that the vast majority of anaphylaxis cases seen in the emergency unit were due to Hymenoptera exposure. Thus, specific immunotherapy may ef-fectively minimize the risk of recurrence. However, a significant number of cases are either under-reported or under-diagnosed, and though less convincing, there were no sever cases of anaphylaxis. Prevention measures and treatment strategies should include awareness programs among health care professionals and patients to encourage follow up and targeted treatment.

Key words: Anaphylaxis, allergy, allergen, antihistamines, hymenoptera
Acceptance June 15 2010

Introduction

Anaphylaxis is a serious and potentially life threatening systemic reaction often involving two or more organs or systems particularly the respiratory and the cardiovascular systems [1]. The severity of anaphylaxis is characterized by several clinical presentations such as anaphylactic shock, acute asthma, laryngeal angio-oedema, and a sys-temic reaction often involving several organs [1]. More-over, severe anaphylaxis may also be classified according to four different grades.

Epidemiological studies identified variations in the inci-dence and prevalence of anaphylaxis worldwide. In addi-tion, differences exist in anaphylaxis risk factors includ-ing age, gender, geographic location, and socio-economic status among different populations. [i, ii, iii] Such variations including clinical presentation, risk factors, and the definition of anaphylaxis, even within the same population, affect the actual prevalence rate of anaphylaxis in various countries. In the United States, for example, approximately 1-15% of the population could be considered “at risk” for having an anaphylactic reaction depending on allergen sub-types (food, drugs, latex, and hymenoptera stings) and the frequency of exposure [4,5]. Similar data from England showed that approximately one in every 1000 individuals suffer from episodes of anaphylaxis. []iv To date, data in the literature indicates discrepancies not only in the definition of anaphylaxis, but also variations in the methods used in data collection suggesting that anaphylaxis is under-recognized and under-reported [7,8].

It is worth noting that patients experience first episodes of anaphylactic attack at a very early age and often in their homes [7]. In fact, the risk of being allergic was shown to be higher in childhood than in adulthood among male subjects, whilst women were more frequently diagnosed with anaphylaxis in a later stage of life. Whilst early sen-sitization may be of importance, the severity of anaphylaxis may also increase with age as supported by finings that most of deaths due to anaphylactic shock occur in older age population and in the emergency departments [7].

In spite of the existing evidences, limited information is available with regard to the patient characteristics, causa-tive allergens, and the current clinical practice and treat-ment of anaphylaxis in the United Arab Emirates. The current study is, therefore, was designed to retrospectively assess the clinical characteristics of anaphylactic patients among emergency departments visitors in a tertiary hospi-tal namely Tawam Hospital, Al-Ain, UAE.

Material and Methods

We collected a retrospective data from anaphylactic pa-tient charts amongst the visitors of Tawam hospital emer-gency department in the period between January 2007 to January 2008. Data pertaining patient’s age, sex, clinical features, past history of allergy, type of the allergen, treatment and outcome (death, discharge, re-admission, and follow up in allergy clinic) in a two page question-naire.

Results

Table 1: Demographic variables of the patients.

  No UAE Na-
tionals
Age SBP DBP
Group (%) ٭(%) Mean ± SD Mean ± SD Mean± SD
Females 45 (37) 38 (84) 25 ± 17 133 ± 21 82 ±2
Males 78 (63) 65 (83) 21 ± 17 131 ± 20 79 ±14

٭Within each group, SBP; systolic blood pressure, DBP; diastolic blood pressure, SD; standard deviation.

Table 2. Number and percentage of past history episodes of allergic reactions and knowledge of the triggering allergen.

  N %
Patients with no known allergy 8 6.5
Patients with known allergy 85 69.1
Type of allergen (No) 58 68.2
Type of allergen (Yes) 27 31.8
Missing data 30 24

N; number of subjects

Table 3. Patient’s report of history of allergy: distribution by gender

Gender Allergy Total
No Yes Do not Know
Female – N (%) 3 (6.7%) 31 (68.9%) 11 (24.4%) 45 (100%)
Male – N (%) 5 (6.4%) 54 (69.2%) 19 (24.4%) 78 (100%)

Figure 1

Figure 1. Self reported distribution of causative allergens (percentage) regarding the current episodes of anaphy-laxis among emergency unit patients.

A total number of 123 patients (mean age ± SD; 22.5 ± 17.0 years) were included in the final analysis. The demographic variables of the subjects are shown in table 1. 85 (69.1%) subjects indicated that they have known history of allergic disease. Of these, only 27 (31.8%) subjects indicated that they are aware of the triggering allergen (Table 2). No significant differences regarding patient’s past history of allergic diseases and knowledge of the triggering allergens were observed between females and males (Table 3). Regarding the current episode of anaphylaxis, 98 % of the total number reported knowledge of the triggering allergen, the overwhelming majority of which were exposed to hymenoptera (ants, wasps, and bees) (77%), and though surprisingly, a significant number of cases were recorded as having been exposed to scorpion bites (21.1%) (Figure 1). Symptoms varied from simple itching to significant involvement of the cardiovascular system. Most of the subjects were transported to hospital by family members rather than paramedic service. Antihistamines and oral steroids were the treatment of choice. Overall, no prolonged hospital-stay was observed as all subjects were treated satisfactorily and dis-charged on the same the day.

Discussion

The present study reports that the overwhelming majority (69.1%) of anaphylactic patients have had a known history of allergic diseases. Moreover, approximately 70% of the subjects (males and females) with “history” of allergic diseases did not know about the triggering allergens presumably in the absence of proper diagnosis and treatment follow-up. However, in the current study, patients were mostly reported the triggering agents as the overwhelming majority (77%) were exposed to hymenoptera (ants, wasps, and bees). Surprisingly, a significant number of cases (21.1%) were said to have been exposed to scorpion bites. Further, we show that anaphylactic symptoms varied from simple itching to significant involvement of the cardiovascular system. In addition, our data shows that existing ambulance services were not fully utilized, and that antihistamines and oral steroids were the treatment of choice in all cases. Finally, we observed no prolonged hospital stay as all cases were presumably treated satisfac-torily and discharged on the same the day.

Since its independence, circa 40 years ago, the UAE government has undertaken rapid development projects heav-ily investing in urbanization, education, and health ser-vices. As a result vast areas of the desert-land has been cultivated and is now significantly contributing not only to the counters’ agricultural production capacity, but also the ever changing environmental landscape in terms of forestry plantations and public gardens. [,]vvi In spite of these impressive and indeed extraordinary development programs, the increased urbanization and vast plantations may have led to a significant change in the natural desert fauna. Consequently, insect population, some of which may even pose a potential public health problem [14], may have increased substantially. In this context, existing evidences indicate that the known types of ants, for example, have increased significantly in the past decades or so [14]. Further, Pachycondyla sennaarensis or Samsum ant (SA), is known to be common in the Arabian Penin-sula and repeated stings may, in fact, cause fatal anaphylaxis [7].

We hypothesize, that possible changes in the environmental landscape of the country, may explain, in part, the apparently high number of subjects (one third) who did not report past history of anaphylaxis (incidence). This hypothesis is further supported by the high number of patients who were exposed to Hymenoptera (ants, wasps, and bees) stings as opposed to other types of triggering allergens; food and drugs. Nonetheless, this data suggests not only a significantly high number of new cases (incident), but also lack of follow up in specialized allergy clinics where patients could possibly benefit from more intense investigations and adequate treatment. This is particularly important given the high exposure Hymenoptera and the usefulness of immunotherapy.

However, while such findings may have, presumably, been expected given the circumstances, the lack of knowledge about the triggering allergen reported by a considerably number of patients in this study is of particular concern. Possibility is high that many patients do not actually seek medical help to diagnose and identify the culprit allergens and even more worrisome, they may also not know the serious consequences of reoccurring epi-sodes of anaphylaxis hence necessitating a major public health awareness campaign aimed at increasing public awareness on the subject. It should be noted however, that patients may have also visited other hospitals in the city and thus the current findings may not be indicative of the prevalence rate of anaphylaxis in the general population. Another possibility may involve the current practice in the emergency units which does not seem to take into consideration the importance of follow up and adequate treatment. This is particularly indispensable as there are evidences that vigilance to avoid the triggering allergens and to certain extent a successful immunotherapy may minimize morbidity and mortality. [] viiIt is needless to mention that there is a pressing need for better preventive measures, and treatment strategies.

Regardless of their past history, the overwhelming majority of patients (77%) were exposed to hymenoptera (ants, wasps, and bees), and though surprisingly, a significant number of cases (21.1%) were recorded as having been exposed to scorpion bites. As mentioned before, insect bites especially black samsum ant (Pachycondyla sennaarensis) are common in Arabia with significant adverse effects, and though this study may not provide further insights, it is in line with similar reports from other Gulf States [11]. Moreover, scorpion bites do not necessarily lead to anaphylaxis. However, investigators in the USA reported a significant cross-reactivity between fire ant whole-body extracts and scorpion venom in at least some individuals who experienced acute allergic reactions after a first episode of scorpion sting [11]. These allergic reactions occurred mainly in specific geographic locations where imported fire ants and the common striped scorpion are endemic [18]. Such findings highlight the pressing need to improve diagnosis, follow up and to understand the specific triggers and the consequences of insect bites particularly among the children in the Arabian Peninsula.

Limitations

The current study may have had some limitations. First, our study may have been affected by the relatively small sample size, presumably, due to under-reported and under-diagnosed cases of anaphylaxis in the emergency department. Nonetheless, although the findings of this study are important in terms of understanding the characteristics, severity, and indeed current practice in the treatment of anaphylactic patients, the findings may not be generalizable to the wider community and thus have limited clinical significance. Second, as most of the patients were discharged within the same day, one may assume a considerable number of cases being under diagnosed or otherwise under reported thus leading to discrepancies in the total number of visits that can actually be identified as anaphylaxis in the hospital records. Third, as is the case in many other studies, relying on patient charts produces several problems; under reporting, lack of consistence in coding system and indeed incomplete information. In this regard, although the study subjects were discharged on the same day as indicated in the charts, we observed a significant number of anaphylactic patients in the hospital wards. However, we could not establish, from the current study, any foreseeable reasons for such discrepancies. Nonetheless, these observations may indeed provide an opportunity to improve patient information and the cur-rent coding systems especially while coding for causative allergens, level of severity, and treatment regimens in the emergency unit. It is worth noting, however, that since the completion of this study, substantial improvements may have been made in the hospital systems and thus the present findings should be reviewed in light of these changes.

Conclusion

In this retrospective study, we report that the majority of anaphylaxis cases seen in the emergency unit are primarily due to Hymenoptera exposure, thus highlighting the importance of targeted and specific immunotherapy which may effectively minimize the risk of recurrence. Our data shows a considerable under reporting and under diagnosing of anaphylaxis in the emergency unit and though less convincing no sever cases were noted. Prevention measures and treatment strategies should include awareness programs among health care professionals and patients to encourage follow up and targeted treatment.

Acknowledgement

We gratefully acknowledge generous financial support from UAE University Research Affairs. We also wish to acknowledge support from Tawam John Hopkins Hospital, Al-Ain, UAE.

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Correspondence:
Shirina Alsowaidi

Department of Internal Medicine
Faculty of Medicine and Health sciences
UAE University
P O Box: 17666
Al-Ain, United Arab Emirates
Tel: 0097137137399, Fax: 0097137672995
E-mail: shirina.alsowaidi(at)uaeu.ac.ae

Biomedical Research Volume 21 Issue 4
Biomedical Research 2010; 21 (4): 406-410

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