Acute urticaria presenting in the emergency room of a general hospital

Acute urticaria and cardiovascular diseases

BACKGROUND

Acute urticaria (AU), characterized by sudden skin wheals, has been associated with various triggers. While chronic urticaria's cardiovascular comorbidities have been studied, AU's associations remain largely unexplored.

OBJECTIVE

This study aimed to identify prevalent cardiovascular comorbidities in AU patients and assess their clinical significance.

METHODS

A retrospective cohort study used data from Leumit Health Services, matching AU patients with controls. Demographic, clinical, and laboratory data were analyzed. Statistical analyses included Fisher's Exact Test and Mann-Whitney U test.

RESULTS

The AU group (72,851 individuals) showed no sex/ethnic distribution differences from controls (291,404 individuals). Systolic blood pressure, weight, BMI, glucose, hemoglobin A1c, C-reactive protein, eosinophil counts, total IgE levels were higher in AU (p < 0.001). Several cardiovascular comorbidities showed significant associations with AU, including valvular heart diseases (aortic regurgitation, mitral regurgitation, and pulmonary valve stenosis), cardiac arrhythmias (atrial fibrillation and others), deep vein thrombosis, diseases of capillaries, peripheral artery disease, cerebrovascular disease, coronary artery disease, and inflammatory heart diseases (pericarditis, heart failure, and hypertension) (p < 0.05). Medications, including antihistamines and glucocorticoids, were more prevalent in the AU group (p < 0.001).

CONCLUSION

This study's findings underscore the importance of recognizing cardiovascular comorbidities in AU patients and considering their implications for management. The observed associations provide insight into potential shared mechanisms between AU and cardiovascular diseases, though further research is needed to validate and expand upon these findings.

Treatment of acute urticaria: A systematic review

There are only a few clinical trials which address the treatment of acute urticaria (AU). Especially, the added value of systemic corticosteroids to antihistamines is unclear in treatment of severe AU. To review the existing evidence-based approaches for AU treatment. A systematic electronic search was done in PubMed and Web of Science to retrieve all studies on the treatment of patients with AU. A descriptive synthesis was conducted based on the PRISMA statement. Quality assessment was independently performed by both reviewers ('Cochrane risk-of-bias tool' for RCTs). Ten randomized controlled trials (RCTs) (n = 857 participants) were included. Four studies assessed corticosteroid effectiveness added to antihistamines and six studies compared the efficacy of H1 and/ or H2 -antihistamines. The addition of corticosteroid (prednisone) to an antihistamine (levo)cetirizine did not improve symptoms of AU compared to antihistamine alone in two out of three RCTs. The combination of diphenhydramine (50 mg, IV) and ranitidine (50 mg, IV) or cimetidine (300 mg, IV) was most efficient for relief of urticaria in two out of five studies. Most frequent adverse effects were sedation and drowsiness. Recent guidelines on urticaria treatment mainly focus on chronic urticaria rather than on AU. Moreover, only few, small RCTs provide evidence for the management of AU. Thus, the state-of-the-art management of this frequent condition remains unclear. The addition of corticosteroids to an antihistamine as treatment for AU needs to be further investigated. Well-designed, high-quality interventional trials are needed to establish evidence-based treatment guidelines for AU.

The impact of meteorological parameters on the number of applications to the emergency department with acute urticaria: A retrospective study

The study aimed to investigate the relationship between the patients who applied to the emergency department with acute urticarial and meteorological factors and determine the associated weather conditions. The relationship between acute urticaria patients who applied to the emergency department of a training and research hospital in a city with high altitude and continental climate characteristics in the eastern part of Turkey between January 2019 and December 2019 and meteorological data was evaluated retrospectively. The necessary data for the weather were obtained from the data of the Erzurum Meteorology Directorate, and the patient data were obtained from the hospital information management system and patient files. The meteorological data of the patients at the date of admission and the characteristics of the patients at that date were compared. The study identified 691 patients who applied to the emergency department diagnosed with urticaria in 2019. According to the seasons, it was observed that the patients applied most frequently in the summer months [n = 239; 34.6%]. In the univariable regression model, which was created by taking the values of weather events as a reference on the days when the urticaria presentation was not observed (Group I), it was determined that every 1-hour increase in the sunshine hour increased the probability of urticaria by 7.4% (p = 0.018). When the meteorological parameters on the days without urticaria (Group I) and the days with urticaria presentation (Group II) were compared, the sunshine hours were 7.9 (4.0-10.6) hours in Group II and 6.65 (3.3-8.85) hours in Group I (p = 0.001). Regarding relative humidity, higher humidity rates were observed in Group I compared to Group II (p = 0.009). In terms of mean temperature, daily maximum, and minimum temperature, higher temperature rates were detected in Group II (p<0.001). A relationship was determined between urticaria attacks and relative humidity and daily maximum and minimum temperature in patients who applied to the emergency department with acute urticaria.

Etiological causes in patients with acute urticaria and angioedema: A cross-sectional study

BACKGROUND

Acute urticaria and angioedema are emergency dermatological conditions associated with various etiologic factors.

OBJECTIVE

To determine the etiological causes in patients with acute urticaria and angioedema, and to investigate whether more than one etiological cause was present, along with the patients' laboratory values.

METHODS

The study was conducted in a tertiary hospital with one center. Etiological causes and laboratory parameters in 284 patients diagnosed with acute urticaria and angioedema were retrospectively studied.

RESULTS

A total of 284 patients were included in the study. The mean age of the patients was 42.7 ± 15.6 years, where 163 (57.4%) were women and 121 (42.6%) were men. Acute urticaria and angioedema occurred together in 149 (52.5%) patients. At least one precipitating factor among the predisposing risk factors was present in 220 (77.5%) patients, and more than one precipitating factor was found in 51 (18%) patients. Medication use was found in 157 (55.3%) patients and infection in 54 (19%). The development of urticaria after food consumption was noted in nine (3.2%) individuals. A history of infection and medication intake was present in 50 (17.6%) patients. A joint history of food consumption and medication intake was present in only one patient. Elevated C-reactive protein level was found in 178 (62.7%) patients and elevated anti-streptolysin O titer in 41 (14.4%) patients. Vitamin B12 deficiency was found in 116 (40.8%) patients and vitamin D deficiency in 254 (89.4%).

CONCLUSION

Acute urticaria and angioedema may occur as a result of multiple etiological factors, in which different triggers may be present simultaneously.

The common triggers of urticaria in children admitted to the pediatric emergency room

BACKGROUND

Urticaria frequently causes pediatric emergency department (PED) admissions. Children with urticaria may unnecessarily avoid suspected allergens. We aimed to investigate the possible and exact triggers of urticaria in children admitted to the PED.

METHODS

Medical records of children admitted to the PED within a 1-year period were evaluated for the International Classification of Diseases 10 (ICD-10) L50 urticaria code, noting symptoms, and possible triggers of urticaria. We performed telephone interviews to complete the missing data and further diagnostic tests for IgE-mediated allergies to identify the exact triggers of urticaria.

RESULTS

Among 60,142 children, 462 (0.8%) with the L50 code were evaluated. Possible triggers based on the history and physical examination could be identified in 46%: infections (18%), drugs (11%), foods (8%), infections and drugs (3%), insects (3%), pollen (1%), blood products (0.4%), and vaccines (0.4%). The most frequent infections related to urticaria were upper respiratory tract infections (74.5%), urinary tract infections (13.2%), gastroenteritis (8.2%), and otitis media (4.1%). After a diagnostic workup, IgE-mediated allergic diseases were diagnosed in 6% of patients. Twenty-two percent of the patients had multiple PED admission for the same urticaria flare. Urticaria severity was found to be the most important risk factor for readmissions to the PED (odds ratio: 3.86; 95% confidence interval: 2.39-6.23; p < .001). No relationship between urticaria severity, duration, and the triggers was present.

CONCLUSIONS

Despite detailed diagnostic tests, IgE-mediated allergic triggers were rarely the cause of urticaria in children admitted to the PED. Infections are the most frequent trigger. Severe urticaria causes more frequent readmissions to the PED.

Drug-Related Hypersensitivity Reactions Leading to Emergency Department: Original Data and Systematic Review

The aim of the present study is to describe pharmacological characteristics of drug-related allergies and anaphylaxis leading to the emergency department (ED). An 8-year post hoc analysis on the MEREAFaPS Study database was performed (2012−2019). Subjects who experienced drug-related hypersensitivity leading to an ED visit were selected. Logistic regression analyses were used to estimate the reporting odds ratios (RORs) of drug-related allergies and anaphylaxis adjusting for sex, age classes, and ethnicity. In addition, a systematic review of observational studies evaluating drug-related hypersensitivity reactions leading to ED visits in outpatients was performed. Out of 94,073 ED visits, 14.4% cases were drug-related allergies and 0.6% were anaphylaxis. Females accounted for 56%. Multivariate logistic regression showed a higher risk of drug-related allergy among males and all age classes < 65 years, while a higher risk of anaphylaxis was observed for females (ROR 1.20 [1.01−1.42]) and adults (ROR 2.63 [2.21−3.14]). The systematic review included 37 studies. ED visits related to allergy and anaphylaxis ranged from 0.004% to 88%, and drug-related allergies and anaphylaxis ranged from 0.007% to 88%. Both in our analysis and in primary studies, antibacterials, analgesics, and radiocontrast agents were identified as the most common triggers of hypersensitivity.

Acute Urticaria and Anaphylaxis: Differences and Similarities in Clinical Management

Acute urticaria is a common condition that presents with wheals and/or angioedema. However, these symptoms are also frequent in anaphylaxis, a life-threatening reaction that should be immediately diagnosed and treated. In both, mast cells play a central role in the physiopathology. Causes and triggers of acute urticaria and anaphylaxis are similar in general, but some peculiarities can be observed. The diagnostic approach may differ, accordingly to the condition, suspicious causes, age groups and regions. Adrenaline is the first-line treatment for anaphylaxis, but not for acute urticaria, where H1-antihistamines are the first choice. In this paper, we review the main aspects, similarities and differences regarding definitions, mechanisms, causes, diagnosis and treatment of acute urticaria and anaphylaxis.

The Role of Bloodletting and Cupping in Severe Acute Urticaria and Angioedema as Skin Emergencies in Persian Medicine

Objectives

Some dermatological diseases can be life-threatening. Urticaria and angioedema are common reasons for patients to seek treatment at an emergency department. Severe, generalized urticaria and angioedema can endanger patients’ lives by involving the airways and causing anaphylactic shock. The humor-based Persian Medicine (PM) concepts of Shara and Mashara, referring to two kinds of skin lesions, have similarities to urticaria and angioedema, respectively. This article aims to provide scientific evidence regarding the application of PM as an early intervention strategy in the emergency management of urticaria and angioedema.

Methods

This was a narrative review of PM studies identified by searching medical databases using search terms related to these diseases, as well as risk-associated keywords such as “fatal”, “death”, “life-threatening”, “emergency”, “cupping”, and “bloodletting”. Data were then compared, interpreted, and analyzed.

Results

PM scholars consider the human body as a unified whole and believe in an inner power (Nature) which stems from the body. When the presence of excessive hot substances cause an imbalance of bodily humors, Nature directs their heated vapors sharply toward the skin, thus causing Shara and Mashara. If there is a high risk of inflammation spreading to vital organs under severe conditions, urgent manual interventions are crucial.

Conclusion

In serious conditions of urticaria and angioedema, Fasd or bloodletting and Hijama can be effective in speeding up the control of lesions and reducing morbidity and mortality. Consequently, the development of integrated Persian and conventional medicines may provide new therapeutic pathways for skin emergencies.

Angioedèmes et médecine d’urgence

Les angioedèmes (AE) sont un motif de recours fréquent aux urgences. Leur morbimortalité n’est pas négligeable compte tenu de l’atteinte fréquente des voies aériennes supérieures. On distingue les AE histaminiques et bradykiniques. Aux urgences, la démarche diagnostique et la conduite à tenir doit être systématique et standardisée afin de ne pas méconnaître un potentiel AE bradykinique. Les AE histaminiques, accompagnés dans la plupart des cas d’une urticaire superficielle, sont de loin les plus fréquents et sont associés parfois à une anaphylaxie, ce qui nécessite alors un traitement par adrénaline immédiat. Ils peuvent être allergiques (médiés par les IgE) et sont alors associés à une anaphylaxie ou non allergiques, et se traduisent cliniquement par une urticaire aiguë ou chronique associée à l’AE. Les AE bradykiniques, d’incidence plus rare, sont également pourvoyeurs de recours aux urgences et particulièrement les AE secondaires aux inhibiteurs de l’enzyme de conversion de l’angiotensine compte tenu de leur importante prescription et de leurs atteintes cliniques de la face, de la langue et du larynx, elles-mêmes pourvoyeuses de recours aux urgences. Les traitements spécifiques d’urgence comprennent principalement l’icatibant et le concentré de C1-inhibiteur. Ils doivent être administrés le plus tôt possible devant l’inefficacité des traitements antiallergiques. Un avis auprès d’un expert du centre de référence pour les AE à kinines peut améliorer les prises en charge en aidant à la démarche diagnostique et en organisant la mise à disposition des traitements spécifiques d’urgence.

Glucocorticoid-induced Changes in the Transcriptional Activity of Genes of the Innate and Adaptive Immune System in the Blood of Patients with Acute Urticaria

Background: A number of the main effects of glucocorticoids (GCs) are their direct action on T cells, mainly through the transcriptional regulation: elevated expression of immune-regulatory proteins, inhibitory receptors, and reduced expression of pro-inflammatory cytokines, co-stimulatory molecules, and cell cycle mediators. But controversies arise due to the clinical effectiveness of GCs in the treatment of acute urticaria. Methods: In our research, we applied a pathway-specific PCR array (Human Innate & Adaptive Immune Responses RT2 Profiler PCR Array, QIAGEN, Germany) to detect and verify innate & adaptive immune responses pathway-focused genes expression in the blood of patients with acute urticaria who received treatment with glucocorticoids in addition to standard therapy. Results: Adding glucocorticoids to standard therapy did not notably affect the nature of the clinical presentation of acute urticaria, which was assessed according to the UAS scale (urticaria activity score). Analysis of the transcriptional profile of peripheral blood mononuclear cells in patients with acute urticaria against the background of glucocorticoid therapy showed the induction expression of the FOXP3 and IL10 genes against the background of repression of the transcriptional activity of the genes for chemokines and cytokines CCL5, CXCL8, IFNG, IL2, IL5, IL17A, IL1B, and TNF. Glucocorticoid-induced changes in the transcriptome also manifested by pronounced repression in genes of CD40 and CD80 (B7-1) co-stimulatory molecules, transcriptional regulators of Th1-cells differentiation - TBX21 and STAT1, Th17 cells - RORC, NLRP3-inflammasome genes, and the transcription factor NFKB1 compared with the control group. Conclusions: Adding glucocorticoids to the standard therapy of acute urticaria has a pronounced immunosuppressive potential at the transcriptome level of immune response genes in the blood; however, it does not have any noticeable clinical effect.

Do Pediatric Emergency Physicians Comply With Guideline Recommendations in Management of Patients With Acute Urticaria?

OBJECTIVES

To determine the level of knowledge and practical preferences of pediatricians regarding acute urticaria (AU) management and to assess the effects of training provided in accordance with the current urticaria guideline recommendations on pediatricians who work in the pediatric emergency department (PED).

METHODS

A theoretical training was provided to pediatricians regarding the diagnosis and treatment of AU in line with current urticaria guideline recommendations. Before the training, pediatricians completed a 10-item questionnaire. This prospective study assesses their treatment approaches in patients admitted to PED because of AU during the 6-month period before and the 1-year period after training.

RESULTS

Four hundred seventeen children in the pretraining and 1085 children in the posttraining periods were treated for AU in PED. Forty-eight pediatricians participated in the training. According to their questionnaire responses, 35% of them used only H1 antihistamine (AH) treatment, 50% used second-generation H1 AH (2nd-GAH) as AHs, 75% preferred the oral route of administration, and 85.4% did not administer systemic corticosteroid (sCS) to all patients. Comparing the practice approaches of the pediatricians in the pretraining and posttraining periods, first-generation H1 antihistamine (1st-GAH) preference rate decreased from 68.4% to 30.3% and the sCS preference rate decreased from 58.5% to 25.7%, while the 2nd-GAH preference rate increased from 31.7% to 69.7% (P < 0.001 for all). No treatments were prescribed for 10.8% of patients before the training and 3% after the training during discharge at home (P < 0.05). Comparing the home treatment choices of the pediatricians in the pretraining and posttraining periods, 1st-GAH preference rate decreased from 11.5% to 5%, while the 2nd-GAH preference rate increased from 78.7% to 91.5% (for both parameters, P < 0.001).

CONCLUSIONS

Practical treatment preferences of pediatricians in the treatment of children with AU differ considerably from both current guideline recommendations and their own theoretical knowledge, and training can enhance pediatricians' compliance with current guideline recommendations.

Acute Urticaria in Inpatients Undergoing Non-emergent Coronary Angiography With Corticosteroid Prophylaxis: A Retrospective Study

Background and Aims: Acute urticaria (AU) is the most frequently reported immediate hypersensitivity reaction in skin by administration of iodinated contrast media (ICM). We aimed to establish the pattern and identify the risk factors of AU among inpatients undergoing non-emergent coronary angiography (CAG) with prophylactic corticosteroids in China.

Methods: Medical records of 19,326 adult inpatients undergoing non-emergent CAG with prophylactic methylprednisolone in 2013–2019 were retrospectively investigated. AU was identified within 1 h post-ICM administration, and diffuse involvement was defined when wheals occur in two or more body parts, including the back, abdomen, chest, and extremities. Age- and sex-matched inpatients (1:4) without AU were randomly selected for assessment of risk factors.

Results: Approximately 0.8% of CAG inpatients had AU, including 101 diffuse and 64 limited form. The diffuse AU was more common in settings of non-diagnostic CAG, iohexol used, average ICM injection≥3 ml/min, recurrent CAG, and past history of immediate hypersensitivity to ICM. Inpatients with preexisting allergies, decreased evaluated glomerular filtration rate, and increased high sensitivity C reactive protein or neutrophil-to-lymphocyte ratio prior to CAG had a higher probability of AU (odds ratio >1, P < 0.05 for all variables). All AU inpatients complained of pruritus, and mild itching predominated. AU dissipated in several days under treatment of ebastine or levocetirizine 10 mg/daily, but ebastine showed superiority.

Conclusions: ICM-induced AU is not uncommon in non-emergent CAG inpatients with prophylactic methylprednisolone. Preexisting allergies, renal dysfunction, and mild inflammation are high-risk factors, and antihistamine monotherapy is a favorable candidate for ICM-related AU.

Risk Factors for Acute Urticaria in Central California

At least 15–20% of the population in the world suffers from urticaria. Allergy triggers contribute to the development of urticaria. Not much is known about the demographic and environmental risk factors that contribute to the occurrence of acute urticaria. Methods: We utilized emergency department data on acute urticaria-related visits managed by the California Office of Statewide Planning and Operations for 201 zip codes located in southern central California (San Joaquin Valley) collected during the years 2016 and 2017. Census data from the same zip codes were considered as a population at risk. Socioeconomic and environmental parameters using CalEnviroScreen (Office of Environmental Health Hazard Assessment, Sacramento, CA, USA) database for the zip codes were evaluated as risk factors. Results: The incidence rate of acute urticaria in San Joaquin Valley during 2016–2017 was 1.56/1000 persons (n = 14,417 cases). Multivariate Poisson analysis revealed that zip codes with high population density (RR = 2.81), high percentage of farm workers (RR = 1.49), and the composite of those with high and medium percentage of poverty and those with high and medium percentage of non-white residents (RR = 1.59) increased the likelihood of the occurrence of acute urticaria. Conclusion: High population density, farm work, poverty and minority status is associated with a high risk of having acute urticaria.

A randomized controlled trial of adding intravenous corticosteroids to H1 antihistamines in patients with acute urticaria

BACKGROUND

Acute urticaria is a common dermatological condition in emergency departments (EDs). The main therapy involves controlling pruritus with antihistamines. Although guidelines have promoted the use of corticosteroids in addition to H1 antihistamines, well-designed clinical trials evaluating this approach are scarce.

METHODS

Adult ED patients with acute urticaria and a pruritus score > 5 on a visual analog scale (VAS) were randomized into three groups: (i) IV chlorpheniramine (CPM) treatment, (ii) IV CPM and IV dexamethasone (CPM/Dex) and (iii) IV CPM and IV dexamethasone with oral prednisolone as discharge medication for 5 days (CPM/Dex/Pred). The primary outcomes were self-reported pruritus VAS scores at 60 min after treatment. We also evaluated 1-week and 1-month urticaria activity scores for 7 days and adverse events.

RESULTS

Seventy-five patients (25 per group) were enrolled. The VAS scores of all groups decreased, but no significant difference was found in the VAS scores at 60 min after treatment between patients in the CPM group (n = 25) and those who received both CPM and dexamethasone (n = 50). At the 1-week and 1-month follow-ups, active urticaria (indicated by the urticaria activity score at 7 days) was more prevalent in the CPM/Dex/Pred group (n = 25) than in the control group.

CONCLUSIONS

The present study did not find evidence that adding IV dexamethasone improves the treatment of severe pruritus from uncomplicated acute urticaria. Oral corticosteroid therapy may be associated with persistent urticaria activity. Due to the lack of clinical benefits and the potential for side effects, using corticosteroids as an adjunctive treatment is discouraged.

Glucocorticoids for acute urticaria: study protocol for a double-blind non-inferiority randomised controlled trial

INTRODUCTION

This study protocol describes a trial designed to investigate whether antihistamine alone in patients with acute urticaria does not increase the 7-day Urticaria Activity Score (UAS7) in comparison with an association of antihistamine and glucocorticoids and reduces short-term relapses and chronic-induced urticaria.

METHODS AND ANALYSIS

This is a prospective, double-blind, parallel-group, multicentre non-inferiority randomised controlled trial. Two-hundred and forty patients with acute urticaria admitted to emergency department will be randomised in a 1:1 ratio to receive levocetirizine or an association of levocetirizine and prednisone. Randomisation will be stratified by centre. The primary outcome will be the UAS7 at day 7. The secondary outcomes will encompass recurrence of hives and/or itch at day 7; occurrence of spontaneous hives or itch for >6 weeks; patients with angioedema at day 7, and 2, 6, 12 and 24 weeks; new emergency visits for acute urticaria recurrences at days 7 and 14, and 3 months; Dermatology Life Quality Index at days 7 and 14, and 3 and 6 months; and Chronic Urticaria Quality of Life Questionnaire at 6 weeks.

ETHICS AND DISSEMINATION

The protocol has been approved by the Comité de Protection des PersonnesSud-Méditerranée II and will be carried out in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. A steering committee will oversee the progress of the study. Findings will be disseminated through national and international scientific conferences and publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03545464.

Levocetirizine and Prednisone Are Not Superior to Levocetirizine Alone for the Treatment of Acute Urticaria: A Randomized Double-Blind Clinical Trial

STUDY OBJECTIVE

We evaluate the efficacy of a 4-day course of prednisone added to antihistamine for the management of acute urticaria in an emergency department (ED).

METHODS

In this double-blind randomized clinical trial, patients were eligible for inclusion if aged 18 years or older and with acute urticaria of no more than 24 hours' duration. Patients with anaphylaxis or who had received antihistamines or glucocorticoids during the previous 5 days were not included. In addition to levocetirizine (5 mg orally for 5 days), patients were assigned to receive prednisone (40 mg orally for 4 days) or placebo. The primary endpoint of the study was itching relief 2 days after the ED visit, rated on a numeric scale of 0 to 10. Secondary endpoints were rash resolution, relapses, and adverse events.

RESULTS

A total of 100 patients were included, 50 in each group. Seven patients in the prednisone group and 8 in the placebo group discontinued treatment. At 2-day follow-up, 62% of patients in the prednisone group had an itch score of 0 versus 76% of those in the placebo group (Δ 14%; 95% confidence interval -31% to 4%). Thirty percent of patients in the prednisone group and 24% in the placebo group reported relapses (Δ 6%; 95% confidence interval -23% to 11%). Mild adverse events were reported by 12% of patients in the prednisone group and 14% in the placebo group.

CONCLUSION

The addition of a prednisone burst did not improve the symptomatic and clinical response of acute urticaria to levocetirizine. This study does not support the addition of corticosteroid to H₁ antihistamine as first-line treatment of acute urticaria without angioedema.

Spring season birth is associated with higher emergency department admission for acute allergic reactions

BACKGROUND

Acute allergic reactions are important causes of emergency department (ED) admission, imposing a significant clinical and organizational burden. Since the season of birth is linked with early exposure to allergens, this study was aimed to establish whether an association exists between season of birth and incidence and severity of acute allergic reactions in the ED.

METHODS

The electronic hospital database was searched to identify all consecutive adult patients who were admitted to the ED for acute allergic reactions (acute urticaria, acute angioedema, urticaria-angioedema and anaphylaxis) during a 1-year period.

RESULTS

The final study population consisted in 588 patients (328 women and 260 men; mean age 43 ± 18 years, range 16-96 years). Increased frequency of ED admission was observed for patients born in spring, whereas the lowest frequency was found for those born in autumn. Patients born in spring exhibited 1.19 and 1.12 higher risk of ED admission for acute allergic reactions compared to those born in autumn and in all other seasons, respectively. This difference remained significant in patients with allergic reaction attributable to drugs and in those with unknown triggers, whereas no pattern of seasonality was observed in patients with allergic reactions attributable to aliments, hymenoptera, chemicals or inhalants. Patients born in spring also exhibited 1.86 and 1.52 higher risk of being admitted to the ED for severe acute allergic reactions compared to those born in autumn and in all other seasons, respectively.

CONCLUSIONS

Patients born in spring appear particularly vulnerable to allergic reactions requiring ED visit.

Utility of ICD-9-CM Codes for Identification of Allergic Drug Reactions

BACKGROUND

The epidemiology of allergic drug reactions is poorly understood due, in large part, to difficulty in identifying true cases in population data sets. Use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes is a potentially valuable approach that requires formal evaluation.

OBJECTIVE

To better understand the utility of ICD-9-CM codes for identification of allergic drug reactions, including the validation of specific codes by chart review.

METHODS

We reviewed randomly sampled medical records of patients treated in the emergency department (ED) between January 1, 2001, and December 31, 2006, with ICD-9-CM codes for drug allergy and E codes (E930-949) for adverse drug reactions.

RESULTS

During the 6-year period, 11,130 charts were identified by ICD-9-CM and E codes and 1,634 were reviewed. Allergic drug reactions were found in 444 (27%) of the reviewed ED visits. The codes that identified the highest percentage of true allergic drug reactions were dermatitis due to drug (693.0; 87%), adverse reaction to drug (995.2; 52%), and anaphylaxis (995.0; 38%). Patients with both an ICD-9-CM code and an E code had a high likelihood of having an allergic drug reaction (76%). Most allergic drug reactions were attributed to antibiotics (42%), intravenous contrast (7%), and nonsteroidal anti-inflammatory drugs (6%). The estimated frequency of allergic drug reactions increased from 0.49% of ED visits in 2001 to 0.94% in 2012.

CONCLUSIONS

Specific ICD-9-CM and E codes can be used in combination to identify allergic drug reactions. Further study of these codes in the inpatient and outpatient settings is necessary to better understand the utility of diagnosis codes for improving epidemiologic research on drug allergy.