Classification and epidemiology of hypersensitivity drug reactions

Healthcare Providers' knowledge, attitudes and practice in relation to drug hypersensitivity reactions at King Abdulaziz Medical City in Riyadh

Background

Drug hypersensitivity reactions (DHRs) are immune-mediated responses triggered by exposure to a drug. DHRs are responsible for serious adverse drug reactions (ADRs) and are considered the fifth leading cause of death. This study aims to assess and evaluate the knowledge, practice, and attitudes of healthcare providers (HCPs) towards DHRs.

Methods

A cross-sectional survey was conducted at King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia. Healthcare providers, including pharmacists, physicians, and nurses, were recruited using a convenience sampling method to complete the survey. The survey comprised three domains: knowledge (14 items), attitudes (5 items), and practices (6 items), utilizing a standardized self-administered questionnaire.

Results

The survey was completed by 373 healthcare providers. The respondents were predominantly female (72.1 %) with a mean age of 33.8 ± 7.8 years. Of the respondents, 64 % were nurses, 25 % pharmacists, and 11.3 % physicians. Educational levels varied, with 53 % holding a bachelor's degree, 22 % an associate degree, and 25 % a master's degree or higher. The median knowledge score was 48. Female healthcare providers, those with advanced levels of education, and physicians had higher knowledge scores compared to male and nurse participants (p < 0.05). One-third of the respondents (33 %) were satisfied with their knowledge of DHRs, and 42 % believed HCPs should receive more advanced training in DHR management. Less than a quarter of HCPs reported inquiring about patients' histories of hypersensitivity reactions.

Conclusions

The study revealed that healthcare workers had a relatively low level of knowledge about drug hypersensitivity reactions and lacked a consensus on DHR management. While displaying a positive attitude towards DHRs, they often did not translate this attitude into consistent clinical practice.

Drug-Induced Enterocolitis Syndrome in Children

Drug-Induced Enterocolitis Syndrome (DIES) is a drug-induced hypersensitivity reaction non-IgE mediated involving the gastrointestinal system that occurs 2 to 4 h after drug administration. Antibiotics, specifically amoxicillin or amoxicillin/clavulanate, represent the most frequent drugs involved. Symptoms include nausea, vomiting, abdominal pain, diarrhea, pallor, lethargy, and dehydration, which can be severe and result in hypovolemic shock. The main laboratory finding is neutrophilic leukocytosis. To the best of our knowledge, 12 cases of DIES (9 children-onset and 3 adult-onset cases) were described in the literature. DIES is a rare clinically well-described allergic disease; however, the pathogenetic mechanism is still unclear. It requires to be recognized early and correctly treated by physicians.

Descriptive analysis of a simplified approach to low-risk drug hypersensitivity reactions

BACKGROUND

Evaluation of drug allergy is intricate because of nonstandardized testing and challenge method variability.

OBJECTIVE

To determine the clinical and epidemiologic characteristics of a large group of patients with suspected drug allergies who underwent 1 or more provocation tests (PT), and to establish whether performing this test in fewer steps is safe and effective.

METHODS

A cross-sectional descriptive study was conducted in patients with suspected drug allergies who underwent a provocation test at the allergy service of Fundación Valle del Lili, Cali, Colombia, from January 2011 to August 2017.

RESULTS

A total of 508 patients underwent 615 PTs; the median age was 34.5 years (range, 1-87 years) and 332 were women (65.3%). The most frequently implicated drugs were nonsteroidal anti-inflammatory drugs in 362 patients (58.9%), followed by beta-lactam antibiotics in 170 (27.6%), and non-beta-lactam antibiotics in 21 (3.4%). The most typically described manifestations were cutaneous urticaria in 282 patients (45.8%) and angioedema in 220 (35.7%). Most patients underwent the PT without performing other previous tests, which were done in only 92 patients (18.3%). Skin prick tests and intradermal reaction tests were performed in 81 patients (15%); all results were negative. In 519 patients (84.3%), the PT was performed in 2 steps without a placebo. Of the PTs performed in 2 steps, 492 (94.8%) had negative results. In addition, PT was performed in 195 patients (37.6%) in whom 2 equal doses of the drug was administered; 186 patients (95.4%) had negative results.

CONCLUSION

Performing an open PT (without previous tests) in 2 steps among patients with low-risk drug reactions is safe. However, every case must be analyzed individually in terms of the risk-benefit ratio.

Attitudes of dental implantologists in Spain to prescribing antibiotics, analgesics and anti-inflammatories in healthy patients

Background

The implantologists frequently prescribe antibiotics, analgesics and anti-inflammatories in dental implant surgery. The aims of this study were to evaluate the attitudes of implantologists in Murcia (Spain) to prescribing antibiotics, analgesics and anti-inflammatories in healthy patients during different implant dentistry procedures, and to see how these are influenced by individual dentist’s academic level, professional experience, and ongoing training (attending courses or reading scientific literature on medication use)

Material and Methods

This cross-sectional study included a total of 200 implantologists from the Murcia area (Spain), who each completed a two-page questionnaire consisting of 26 questions.

Results

The implant procedure in which most dentists (n=97) prescribed antibiotics was multiple implant surgery with flap raising, in which 55.6% of these 97 respondents used a prophylactic antibiotic regime for 7 days after implant placement. All subjects (n=200) prescribed analgesics for eight out of the eleven procedures included in the survey and anti-inflammatories in six. Dentists with higher academic levels or longer professional experience prescribed more antibiotics, but those who underwent continuous training (attending courses or reading scientific literature) reduced antibiotic prescription.

Conclusions

Dentists often prescribed antibiotics, analgesics and anti-inflammatories in almost all implant procedures in healthy patients, but ongoing training reduced the frequency of antibiotic prescription in some procedures.

Key words:Antibiotics, analgesics, anti-inflammatories, dental implant, oral surgery.

Epidemiology of drug hypersensitivity reactions using 6-year national health insurance claim data from Korea

Background Drug hypersensitivity reactions (DHRs) constitute a large portion of adverse drug reactions (ADRs), but studies for DHR incidence based on national data are scarce. Objective This study aimed to estimate the incidence and patterns of DHRs in a Korean population and the associated utilization of medical resources using the national claims data. Setting The retrospective cohort study performed using the national insurance claim database of the Health Insurance Review and Assessment (HIRA) in Korea. Methods The International Classification of Disease 10th revision code was used to identify DHRs with 20 drug induced DHR codes. The claim data with a diagnosis of DHR in the 2009-2014 periods were analyzed. Main outcome and measure The annual incidence and the 6-year incidence rates were calculated. Incidence rate coefficients were analyzed by sex, age, and year. DHRs following with visits of emergency department (ED) or intensive care unit (ICU) were assessed for utilization of medical resources and risk of ER or ICU visits by sex and age Results A total of 535,049 patients with 1,083,507 claims were assessed in the HIRA database for 6 years. DHR incidence was high in the elderly. The risk of ED and ICU visit with DHR was also higher in the elderly than in the young [highest relative risk, RR of ED 2.59 (1.65-4.07), ICU 5.04 (2.50-10.18)]. DHRs related to blood were high in the young age. Conclusion Incidence of DHRs in the real-world clinical practice was higher in the elderly and female. Clinical consequence was more severe in the elderly.

Pharmacokinetics and tolerability of cinitapride in healthy Chinese volunteers: a randomized, open-label, single- and multiple-dose study

Cinitapride (CIN) is a drug for functional dyspepsia. The purpose of the study was to investigate the pharmacokinetics and tolerability of CIN in healthy Chinese volunteers. A randomized, open-label, single- and multiple-dose study was conducted in 12 healthy volunteers. Three different doses of CIN (1, 2, 4 tablets) were given to six groups in the single-dose study, and one tablet (1 mg) of CIN was administered three times a day in the multiple-dose study. Blood samples were collected at predetermined time intervals after CIN dosing and analyzed by LC-MS/MS. Eleven volunteers completed the study. After single dose, the C_max and AUC of plasma increased approximately linearly with dosage; no statistically significant differences were found in pharmacokinetic parameters between three dose groups. After multiple doses, there was no significant change in T_max and t_1/2 compared with the results from the single dose. After repeated doses, AUC_0-t and AUC_0-∞ were increased, while CLz/F slightly decreased. And no differences between male and female. The pharmacokinetic parameters of this study were consistent with study results of non-Chinese subjects. Good tolerability was demonstrated in both single- and multiple-dose studies with dosage range from 1 to 4 mg in healthy Chinese subjects.

Anxiety and Depression Effects During Drug Provocation Test

BACKGROUND

Drug provocation test (DPT) represents the gold standard for the diagnosis of drug allergy. A DPT can be performed in a single-blind placebo-controlled manner. In anxiety and depressive disorders, patients need to be evaluated to understand the nature of placebo reactions.

OBJECTIVE

The aim of this study was to evaluate the psychological profile of patients with reactions to placebo during a DPT.

METHODS

We consecutively enrolled patients with suspected drug allergy undergoing a DPT preceded by the administration of the placebo. All patients underwent the Hospital Anxiety and Depression Scale (HADS), a questionnaire aimed to identify anxiety and depression, before the challenge test.

RESULTS

A total of 196 patients were enrolled into this study: 8 (4%) patients resulted positive to the DPT, 60 (30.6%) demonstrated anxiety or depression based on the HADS, and 54 had at least 1 placebo reaction during drug provocation. There were statically significant correlations between the positivity of the HADS and the finding of a placebo reaction (Fisher's exact test: P < .001), and between the latter and a history of severe reactions to drug (Fisher's exact test: P < .001).

CONCLUSIONS

There is a significant and strong correlation between the loss of psychic equilibrium and the development of a placebo reaction during a DPT. We suggest the use the HADS or other validated questionnaire in clinical practice before a DPT to evaluate the possible psychiatric components.

"Treating Through" Decision and Follow-up in Antibiotic Therapy-Associated Exanthemas

BACKGROUND

Immediate discontinuation or replacement of suspected drugs is considered standard medical care in acute exanthematous skin reactions. In the treatment of bacterial infections, structurally different alternative antibiotics, however, are commonly second choice options due to a suboptimal antimicrobial activity or an unfavorable side effect profile. Nonetheless, "treating through," the continuation of antibiotic treatment despite an objective exanthema, is practiced only rarely.

OBJECTIVE

We aimed to assess whether "treating through" is an option for patients with severe bacterial soft tissue infections (severe cellulitis) who experience maculopapular exanthema (MPE) during antibiotic therapy.

METHODS

We retrospectively reviewed clinical data from 18 patients who developed MPE within a few days after initiation of intravenous antibiotic treatment. A decision to "treat through" was made when the suspected antibiotics (β-lactams, clindamycin, ciprofloxacin) were clinically effective and the benefits of continued treatment outweighed potential risks. Clinical and laboratory findings were closely monitored in an inpatient setting.

RESULTS

In 2 patients, a modification of antibiotic therapy was deemed necessary due to a significant increase of liver enzymes within 4 days after the initial decision to "treat through." Because of a progression of MPE under ongoing treatment with cefuroxime and clindamycin, clindamycin was discontinued in 1 patient. In another 3 patients, antibiotic treatment was modified because of insufficient improvement of the soft tissue infection. In the remaining 12 "treated through" cases, the skin symptoms improved despite unchanged continued antibiotic treatment, and relevant laboratory parameters remained within the normal range.

CONCLUSIONS

Careful risk-benefit assessment may enable the continuation of antibiotic therapy despite MPE, provided that patients are under close medical observation.

Epidemiology of anaphylaxis

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

Drug-Induced Anaphylaxis in Latin American Countries

BACKGROUND

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Drug allergy in tertiary care in Turkey: results of a national survey. The ADAPT study: adult drug allergy perception in Turkey

BACKGROUND

No data are available on the incidence of drug hypersensitivity (DH) reactions in outpatient settings of tertiary allergy/immunology clinics. Our aims were to document the frequency of outpatient hospital admissions due to DH reactions to allergy/immunology clinics in adults and the management of these reactions in real life. We also investigated whether drug allergy affected social and medical behaviours of the patients.

METHODS

This multi-centre study was performed for one year with the participation of 11 out of 16 tertiary allergy/clinical immunology clinics in Turkey. The study group consisted of the patients with DH reactions. Results of a questionnaire including drug reactions and management were recorded.

RESULTS

Among 54,863 patients, 1000 patients with DH were enrolled with a median of 2.1% of all admissions. In real life conditions, the majority of approaches were performed for finding safe alternatives (65.5%; 1102 out of 1683) with 11.7% positivity. Diagnostic procedures were positive in 27% (154/581) of the patients. The majority of the patients had higher VAS scores for anxiety. A total of 250 subjects (25%) reported that they delayed some medical procedures because of DH.

CONCLUSION

Our results documented the frequency of admissions due to DH reactions to allergy/clinical immunology clinics for the first time. Although physicians mostly preferred to perform drug tests in order to find safe alternatives, considering the fact that DH was confirmed in 27% of the patients, use of diagnostic tests should be encouraged, if no contraindication exists in order to avoid mislabelling patients as DH.

Human leukocyte antigen genotypes and trial of desensitization in patients with oxcarbazepine-induced skin rash: a pilot study

BACKGROUND

Skin rash associated with specific antiepileptic drugs occurs not infrequently and it usually necessitates discontinuation of the causative drugs. An alternative strategy is to desensitize the individual to the offending drug. We checked the human leukocyte antigen genotypes and conducted a pilot study to investigate the usefulness and safety of desensitization in pediatric patients with skin rash associated with oxcarbazepine.

METHODS

We enrolled 19 patients with epilepsy who had discontinued oxcarbazepine because of skin rash despite an initial good response and then became refractory to other antiepileptic drugs along with an individual with paroxysmal kinesigenic dyskinesia with a similar situation. High-resolution HLA-A and -B genotyping was performed to investigate the genetic risk. The desensitization began with 0.1 mg daily reaching 120 mg on the thirty-first day. Thereafter, the dose was increased at a rate of 12 mg/day.

RESULTS

Nineteen patients completed the desensitization protocol to a target dosage over 2-5 months. Five patients developed itching and erythema during desensitization, but the symptoms disappeared after withholding a dose increment transiently. There were no human leukocyte antigen genotypes relevant to aromatic antiepileptic drug-induced severe hypersensitivity reactions. The seizure frequency was reduced to less than at baseline in 18 individuals.

CONCLUSION

This study demonstrated 95% efficacy, including 42% seizure-free patients and the favorable tolerability of desensitization to oxcarbazepine in patients with intractable epilepsy and one patient with paroxysmal kinesigenic dyskinesia. Screening for sensitive human leukocyte antigen types and exclusion of severe hypersensitivity reactions should precede desensitization.

Multinational experience with hypersensitivity drug reactions in Latin America

BACKGROUND

Epidemiologic drug allergy data from Latin America are scarce, and there are no studies on specific procedures focusing on this topic in Latin America.

OBJECTIVE

To assess the clinical characteristics and management of hypersensitivity drug reactions in different Latin American countries.

METHODS

An European Network of Drug Allergy questionnaire survey was implemented in 22 allergy units in 11 Latin American countries to report on consecutive patients who presented with a suspected hypersensitivity drug reaction. Each unit used its own protocols to investigate patients.

RESULTS

Included were 868 hypersensitivity drug reactions in 862 patients (71% of adults and elderly patients were women and 51% of children were girls, P = .0001). Children presented with less severe reactions than adults and elderly patients (P < .0001). Urticaria and angioedema accounted for the most frequent clinical presentations (71%), whereas anaphylaxis was present in 27.3% of cases. There were no deaths reported. Nonsteroidal anti-inflammatory drugs (52.3%), β-lactam antibiotics (13.8%), and other antibiotics (10.1%) were the drugs used most frequently. Skin prick tests (16.7%) and provocation tests (34.2%) were the study procedures most commonly used. A large proportion of patients were treated in the emergency department (62%) with antihistamines (68%) and/or corticosteroids (53%). Only 22.8% of patients presenting with anaphylaxis received epinephrine.

CONCLUSION

Nonsteroidal anti-inflammatory drugs and antibiotics were the drugs used in at least 75% of patients. More than half the reactions were treated in the emergency department, whereas epinephrine was administered in fewer than 25% of patients with anaphylaxis. Dissemination of guidelines for anaphylaxis among primary and emergency department physicians should be encouraged.

Contributions of pharmacogenetics and transcriptomics to the understanding of the hypersensitivity drug reactions

Hypersensitivity drug reactions (HDRs) represent a large and important health problem, affecting many patients and leading to a variety of clinical entities, some of which can be life-threatening. The culprit drugs include commonly used medications including antibiotics and NSAIDs. Nontherapeutical agents, such as contrast media, are also involved. Because the pathophysiological mechanisms are not well known and the current diagnostic procedures are somewhat insufficient, new approaches are needed for understanding the complexity of HDRs. Histochemical and molecular biology studies have enabled us to classify these reactions more precisely. Pharmacogenetics has led to the identification of several genes, involved mainly in T-cell-dependent responses, with a number of markers being replicated in different studies. These markers are now being considered as potential targets for reducing the number of HDRs. Transcriptomic approaches have also been used to investigate HDRs by identifying genes that show different patterns of expression in a number of clinical entities. This information can be of value for further elucidation of the mechanisms involved. Although first studies were performed using RT-PCR analysis to monitor the acute phase of the reaction, nowadays high-density expression platforms represent a more integrative way for providing a complete view of gene expression. By combining a detailed and precise clinical description with information obtained by these approaches, we will obtain a better understanding and management of patients with HDRs.

The use of steroids to prevent cutaneous reactions to benznidazole in patients with Chagas disease

The treatment of Chagas disease is limited by the frequent cutaneous side effects of benznidazole. We tested the use of steroids plus escalating doses of benznidazole to prevent this complication in 17 adult patients with chronic Trypanosoma cruzi infection and found extremely good tolerance. A randomized trial is warranted.

Classification and practical approach to the diagnosis and management of hypersensitivity to nonsteroidal anti-inflammatory drugs

Hypersensitivity reactions to aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAIDs) constitute only a subset of all adverse reactions to these drugs, but due to their severity pose a significant burden to patients and are a challenge to the allergist. In susceptible individuals, NSAIDs induce a wide spectrum of hypersensitivity reactions with various timing, organ manifestations, and severity, involving either immunological (allergic) or nonimmunological mechanisms. Proper classification of reactions based on clinical manifestations and suspected mechanism is a prerequisite for the implementation of rational diagnostic procedures and adequate patient management. This document, prepared by a panel of experts from the European Academy of Allergy and Clinical Immunology Task Force on NSAIDs Hypersensitivity, aims at reviewing the current knowledge in the field and proposes uniform definitions and clinically useful classification of hypersensitivity reactions to NSAIDs. The document proposes also practical algorithms for the diagnosis of specific types of NSAIDs hypersensitivity (which include drug provocations, skin testing and in vitro testing) and provides, when data are available, evidence-based recommendations for the management of hypersensitive patients, including drug avoidance and drug desensitization.

Proton pump inhibitors are associated with hypersensitivity reactions to drugs in hospitalized patients: a nested case-control in a retrospective cohort study

BACKGROUND

Previous research has shown that gastric acid suppression by antacid drugs can promote allergic reactions to acid-labile food proteins. No data are available about whether antacid drugs can promote drug hypersensitivity reactions. The most potent and longer lasting inhibition of gastric secretion is provided by proton pump inhibitors (PPIs). We hypothesized that gastric acid suppression by proton pump inhibitors could be causative of drug hypersensitivity reactions during hospitalization.

OBJECTIVE

To estimate the risk of developing drug hypersensitivity reactions during the hospitalization of patients treated with proton pump inhibitors, and other associated factors.

METHODS

A nested case-control in a retrospective cohort study of hospitalized patients from September 2008 to December 2010 (70 771 admissions) was conducted using the registry of cases of interconsultations to the Allergy Department (161 confirmed cases of drug hypersensitivity reactions). A total of 318 controls were matched by first drug suspected in the hypersensitivity reaction, time of admission, age, gender and hospitalization wards.

RESULTS

The relative risk of drug hypersensitivity reaction occurrence during hospitalization of patients treated with PPIs compared with those not treated in the period of study was significant (RR: 3.97; 95% CI: 1.97-8.29). After controlling for confounders in the nested case-control cohort, the use of PPIs persists as a predisposing factor (OR: 4.35; 95% CI: 2-9.45). Personal history of drug allergy and a long hospitalization time were other predisposing factors of drug hypersensitivity reactions (DHRs). The hazard that a DHR has occurred during PPI treatment was 3.7% per day. The hazard for immediate or accelerated reactions was 1.706 (P = 0.003) times that of delayed reactions.

CONCLUSION AND CLINICAL RELEVANCE

In hospitalized patients, the use of proton pump inhibitors was associated with a significant increase risk of drug hypersensitivity reactions along with a personal history of drug allergies and long hospitalization time.

Immunologic evaluation of drug allergy

Hypersensitivity drug reactions (HDR) consist of an individual abnormal response with the involvement of the immunological system. In addition to specific immunological mechanisms where specific antibodies or sensitised T cells participate, release of inflammatory mediators by non-specific immunological recognition may also occur. Within this category are one of the most common groups of drugs, the non-steroidal anti-inflammatory drugs. In addition to chemical drugs new emerging ones with an increasing protagonism are biological agents like humanised antibodies and others. For IgE dependent reactions both in vivo and in vitro tests can be used for the immunological evaluation. Sensitivity of these is not optimal and very often a drug provocation test must be considered for knowing the mechanism involved and/or establishing the diagnosis. For non-immediate reactions also both in vivo and in vitro tests can be used. Sensitivity for in vivo tests is generally low and in vitro tests may be needed for the immunological evaluation. Immunohistochemical studies of the affected tissue enable a more precise classification of non-immediate reactions. The monitorization of the acute response of the reactions has given clues for understanding these reactions and has promising results for the future of the immunological evaluation of HDR.

Allergy to betalactam antibiotics in children: results of a 20-year study based on clinical history, skin and challenge tests

Studies based on skin and challenge tests have shown that 12-60% of children with suspected betalactam hypersensitivity were allergic to betalactams. Responses in skin and challenge tests were studied in 1865 children with suspected betalactam allergy (i) to confirm or rule out the suspected diagnosis; (ii) to evaluate diagnostic value of immediate and non-immediate responses in skin and challenge tests; (iii) to determine frequency of betalactam allergy in those children, and (iv) to determine potential risk factors for betalactam allergy. The work-up was completed in 1431 children, of whom 227 (15.9%) were diagnosed allergic to betalactams. Betalactam hypersensitivity was diagnosed in 50 of the 162 (30.9%) children reporting immediate reactions and in 177 of the 1087 (16.7%) children reporting non-immediate reactions (p<0.001). The likelihood of betalactam hypersensitivity was also significantly higher in children reporting anaphylaxis, serum sickness-like reactions, and (potentially) severe skin reactions such as acute generalized exanthematic pustulosis, Stevens-Johnson syndrome, and drug reaction with systemic symptoms than in other children (p<0.001). Skin tests diagnosed 86% of immediate and 31.6% of non-immediate sensitizations. Cross-reactivity and/or cosensitization among betalactams was diagnosed in 76% and 14.7% of the children with immediate and non-immediate hypersensitivity, respectively. The number of children diagnosed allergic to betalactams decreased with time between the reaction and the work-up, probably because the majority of children with severe and worrying reactions were referred for allergological work-up more promptly than the other children. Sex, age, and atopy were not risk factors for betalactam hypersensitivity. In conclusion, we confirm in numerous children that (i) only a few children with suspected betalactam hypersensitivity are allergic to betalactams; (ii) the likelihood of betalactam allergy increases with earliness and/or severity of the reactions; (iii) although non-immediate-reading skin tests (intradermal and patch tests) may diagnose non-immediate sensitizations in children with non-immediate reactions to betalactams (maculopapular rashes and potentially severe skin reactions especially), the diagnostic value of non-immediate-reading skin tests is far lower than the diagnostic value of immediate-reading skin tests, most non-immediate sensitizations to betalactams being diagnosed by means of challenge tests; (iv) cross-reactivity and/or cosensitizations among betalactams are much more frequent in children reporting immediate and/or anaphylactic reactions than in the other children; (v) age, sex and personal atopy are not significant risk factors for betalactam hypersensitivity; and (vi) the number of children with diagnosed allergy to betalactams (of the immediate-type hypersensitivity especially) decreases with time between the reaction and allergological work-up. Finally, based on our experience, we also propose a practical diagnostic approach in children with suspected betalactam hypersensitivity.

Midazolam hypersensitivity during the transportation to theater -A case report-

This report describes a rare case of perioperative midazolam hypersensitivity in a patient without any history of allergy. A 39-year-old man was admitted for endoscopic pansinus surgery. During transportation to the operating room after injecting antibiotic and midazolam intravenously, the patient complained of shortness of breath. At 3 months after the event, an intradermal sensitivity test for midazolam proved positive indicating the incident was caused by midazolam hypersensitivity.

Allergic and hypersensitivity reactions in the intensive care unit

Hypersensitivity reactions are defined as immunologically based adverse reactions to chemicals or medicinal agents. These reactions are common in the intensive care unit and can present as a simple, mildly symptomatic rash or as life-threatening anaphylactic reactions. Hypersensitivity reactions have traditionally been classified as types I to IV reactions based on the underlying immune mechanisms, although the clinical relevance of the classification is unclear, and new subtypes to this system have been recently proposed. Given the immunologic and often unpredictable nature of these reactions, avoidance or prevention is not a feasible option. Therefore, management has primarily consisted of withdrawal of potential offending agents, supportive therapy, symptomatic management, and, in some specific examples, targeted pharmacotherapy. This article outlines the background and types of hypersensitivity reactions and provides descriptions and management strategies when applicable to common types of hypersensitivity reactions encountered in the intensive care unit.

Delayed cutaneous manifestations of drug hypersensitivity

Drugs may elicit a considerable variety of clinical signs, often affecting the skin and the mucous membranes. The most common are maculopapular exanthemas and urticaria, more rarely pustules, bullae vasculitic lesions, and lichenoid lesions may also be observed. Apart from the morphology, the chronology of the occurrence and the evolution of single skin lesions and exanthema are also paramount in the clinical diagnosis of cutaneous drug hypersensitivity. Often, the skin represents the only organ manifestation; however, it may be the herald for a systemic involvement of internal organs, such as in severe drug-induced hypersensitivity syndromes or anaphylaxis.

Acute symptoms of drug hypersensitivity (urticaria, angioedema, anaphylaxis, anaphylactic shock)

Drug hypersensitivity reactions (HSRs) are the adverse effects of drugs which, when taken at doses generally tolerated by normal subjects, clinically resemble allergy. Immediate-reaction of drug HSRs are those that occur less than 1 hour after the last drug intake, usually in the form of urticaria, angioedema, rhinitis, conjunctivitis, bronchospasm, and anaphylaxis or anaphylactic shock. Acute urticarial and angioedema reactions are common clinical problems frequently encountered by internists and general practitioners. They are not specific to drug allergic reaction, and can be caused by various pathogenic mechanisms. Despite the benign course of urticaria and angioedema, a mucocutaneous swelling of the upper respiratory tract could be life-threatening by itself or a feature of anaphylaxis. This article reviews acute symptoms of drug HSR-related urticaria, angioedema, anaphylaxis, and anaphylactic shock, and how clinicians should approach these problems.

Role of epidermal dendritic cells in drug-induced cutaneous adverse reactions

Drug-induced adverse reactions (ADR) include any undesirable pharmacological effect that occurs following drug administration at therapeutic doses. The appearance of ADR significantly limits the use of drugs in as much as their clinical symptoms may range from very mild discomfort such as cutaneous rash, up to very severe, or even fatal tissue necrolysis such as the Stevens Johnson syndrome.One of the most frequently involved organ during ADR is the skin. Drug-induced cutaneous reactions (CDR) incidence is variable but they may appear in 2-3% of ambulatory patients, and it may increase to 10-15% when patients are hospitalized, or even be as high as 60% when co morbidity includes the presence of virus, bacteria, or parasites.Due to the fact that skin is one of the organs most frequently involved in ADR, in this work we analyze and propose a mechanism by which epidermal dendritic cells operating as the sentinels of the skin neuro-immune-endocrine system may contribute to CDR via either immunogenic or tolerogenic immune responses towards drugs, whenever they are administered topic or systemically.

Parental-reported drug allergy in 6- to 9-yr-old urban schoolchildren

Epidemiologic studies about the prevalence of adverse drug reactions in children are scarce compared to reports in adults. To assess the prevalence of parental-reported drug allergy in 6- to 9-yr-old urban school children, we performed a cross-sectional study of 6- to 9-yr-old urban children from the eastern Black Sea region of Turkey during the year 2004, using a self-administered questionnaire by parents. Response rate was 81.6% (2855/3500). The prevalence of parental-reported drug allergy was 2.8% (81/2855). The most common parental-reported drugs were penicillins and other beta-lactams (59.3%), trimethoprim-sulfamethoxazole (11.1%), and acetylsalicylic acid and other non-steroidal anti-inflammatory drugs (NSAIDs) (9.9%). The most commonly reported clinical manifestations were cutaneous (n = 76, 93.8%) followed by gastrointestinal (n = 17, 21%) symptoms. In 19 (23.5%) children, the reaction involved more than one organ system. Of these 19 children, 14 used beta-lactams. Systemic reactions were not reported with NSAIDs. Medications were taken by mouth in 88.9% of the reactions. Most of the reported allergic reactions occurred in the first day of treatment (61.7%). The reported time to reaction after the last intake of the drug was <2 h in 35 (43.2%) children and 2-24 h in 45 (55.6%). Oral reactions occurred later than reactions to parentally administered drugs. Parents of 58 children (71.6%) reported that they completely avoided the suspected culprit drug following the reaction. Relapse occurred after re-administration of the drug in 21 (25.9%) children. A diagnostic approach for drug allergy was not undertaken in any of the children. This study may provide some information about the prevalence of drug allergy, although it is based on parental perception and results are unlikely to conform well to true prevalence.

Clinical presentation and time course in hypersensitivity reactions to beta-lactams

BACKGROUND

beta-lactam hypersensitivity reactions are classified as immediate or nonimmediate. Diagnosis is usually based upon skin tests and provocation challenges.

OBJECTIVE

The time course of the reactions in proven beta-lactam hypersensitivities was studied and then correlated with the symptoms to determine the relationship between the clinical presentations and the time course.

METHOD

All of the patients who consulted between 1996 and 2004 for a suspected beta-lactam hypersensitivity reaction were studied. Two hundred and ten patients with a proven hypersensitivity reaction diagnosed according to the European Network on Drug Allergy were included in the present study.

RESULTS

Of the patients, 36.7% had urticaria as a single symptom, 19.1% anaphylaxis without shock, 17.6% anaphylactic shock and 19.1% maculopapular exanthema. Anaphylactic shock and anaphylaxis mostly occurred within 1 h after drug administration. Exanthema mainly occurred after 24 h. Urticaria as a single symptom occurred at any time. A firm diagnosis was determined using immediate-reading skin prick (10.0%) and intradermal tests (38.1%), late-reading skin tests (19.1%) or provocation tests (32.9%).

CONCLUSION AND CLINICAL IMPLICATION

Depending on the time course of the reaction, three clinical groups were identified: anaphylaxis and anaphylactic shock (immediate reaction); maculopapular exanthema (late reaction) as well as urticaria (immediate and late reaction).

Anaphylaxis and toxic epidermal necrolysis or Stevens-Johnson syndrome after nonmucosal topical drug application: fact or fiction?

BACKGROUND

Drug-induced anaphylaxis and toxic epidermal necrolysis (TEN) or Stevens-Johnson syndrome (SJS) represent severe immediate and delayed-type adverse drug reactions (ADRs), respectively. Occurrence of such reactions after topical drug application has only rarely been reported. Hence, we compiled a large number of such cases which we systematically analyzed.

METHODS

All such cases contained in the ADR database of the competent pharmacovigilance authority in Germany and cases reported in literature were identified, evaluated and analyzed with regard to potential risk factors. Since the application of drugs to mucous membranes facilitates their entry to the systemic circulation only cases occurring after non-mucosal topical drug application were considered.

RESULTS

After evaluation 28 anaphylaxis database cases and 48 anaphylaxis literature cases remained for analysis. Application to skin wounds or to skin with impaired barrier function was identified as a risk factor in 10/28 (36%) of the database cases and in 42/48 (88%) of the literature cases. In 9/28 database cases (32%), anaphylaxis was induced by drugs used for their hyperemizing effect and, in 8/28 cases (29%) by antibiotics or antiseptics. In the literature cases, anaphylaxis was induced by antibiotics or antiseptics in 35/48 cases (73%). Only one SJS database case and one TEN literature case remained after case evaluation.

CONCLUSION

Anaphylaxis does occur after non-mucosal topical drug administration. Application of drugs to skin wounds or to skin with impaired barrier function may pose a risk factor for its occurrence. TEN or SJS following non-mucosal topical drug application seems to be extremely rare.

Fluoroquinolone-Associated Anaphylaxis in Spontaneous Adverse Drug Reaction Reports in Germany

BACKGROUND

The frequency of fluoroquinolone-associated anaphylaxis has been estimated to be 1.8-23 per 10 million days of treatment based on spontaneous reports. It is unknown whether there are differences between the reporting rates of anaphylaxis with individual fluoroquinolones. According to pathophysiology, anaphylaxis may be immune mediated (anaphylactic) or not (anaphylactoid). The latter may occur after first-ever intake since no sensitisation phase is necessary.

OBJECTIVE

To analyse spontaneous reports of fluoroquinolone-associated anaphylaxis contained in the spontaneous adverse drug reaction database of the Federal Institute for Drugs and Medical Devices in Germany with regard to differences in reporting rates between various fluoroquinolones, the previous intake and the time to onset of the reaction.

METHODS

All fluoroquinolone-associated cases of anaphylaxis, anaphylactic shock, and anaphylactic/anaphylactoid reaction spontaneously reported to the Federal Institute for Drugs and Medical Devices between 1 January 1993 and 31 December 2004 were identified and assessed with regard to the correctness of the diagnosis of anaphylaxis, the causal relationship with the drug, the previous intake of fluoroquinolones and the time to onset of the reaction.

RESULTS

In 166 of 204 cases identified, the diagnosis of anaphylaxis and a causal relationship with the drug were considered at least possible. Moxifloxacin, levofloxacin, ciprofloxacin and ofloxacin accounted for 90 (54%), 25 (15%), 21 (13%) and 16 (10%) of the 166 cases, respectively. The corresponding reporting rates per 1 million defined daily doses based on crude estimates of exposure were 3.3, 0.6, 0.2 and 0.2 for moxifloxacin, levofloxacin, ciprofloxacin and ofloxacin, respectively. The occurrence of anaphylaxis after the first dose or within the first three days was reported in 71 of 166 (43%) cases, but no information on prior exposure with this or any other fluoroquinolone was provided with these reports. In 21 of 166 (13%) cases, the reaction occurred within the first 3 days and it was stated that the particular fluoroquinolone had never been taken before.

CONCLUSIONS

Anaphylaxis appears to be associated with the fluoroquinolone class of antibacterials. Observed differences in reporting rates should be further investigated. Fluoroquinolone-associated anaphylaxis may occur after first-ever intake of the agent.

Immediate-type allergy to drugs and related compounds: evaluation and management

Adverse drug reactions (ADR) constitute a major health issue in outpatient and inpatient clinical settings. An allergic drug reaction is an immunologically mediated adverse drug reaction that exhibits specificity and recurrence on re-exposure to the offending and/or cross-reactive compound(s). Diagnosis of drug allergy is difficult, as a broad spectrum of different drugs can elicit various immune-mediated diseases with distinct (sometimes unclear) pathomechanism, the exact structure (epitope) that causes the reaction is frequently unknown, the presence of an in vitro or in vivo test results might not be predictive of a clinical situation, and the gold standard or reference test for diagnosis, the drug challenge, is a complicated and sometimes dangerous endeavour. Nevertheless, during the past few years serious attempts have been made to standardise and validate in vitro and in vivo techniques for the diagnosis of drug allergy. New techniques, e.g. flow-assisted analysis of in vitro basophil activation, are replacing older ones like histamine release for immediate-type hypersensitivity reactions. However, additional comprehensive studies are required to further validate the technique and allow its entrance in mainstream diagnostic use, particularly for non-IgE-mediated hypersensitivity. This review attempts to summarize the major causes of immediate hypersensitivity reactions to drugs and related compounds. Special attention is paid to the diagnostic and therapeutic management of this common iatrogenic complication.

Elucidating mechanisms of drug-induced toxicity

The early and high-throughput application of assays for non-genetic toxicity is of great interest to the pharmaceutical industry, although few systems have been validated as being of good predictive value. New technologies could enable toxicity to be studied in the context of systems biology. An important factor to be considered is the metabolism of drugs to reactive intermediates. Chemical reactions of these with cell and tissue nucleophiles are relatively well understood, but predicting how biological modifications will affect signalling and regulatory networks remains a challenge. Some of these pathways could be useful as sentinels for toxicity. This article will cover some examples of drug toxicity and the prospects for future technology development.