Epidemiology of severe drug hypersensitivity

Severe cutaneous adverse reactions associated with immune checkpoint inhibitors therapy and anti-VEGF combination therapy: a real-world study of the FDA adverse event reporting system

BACKGROUND

Immune checkpoint inhibitors (ICIs) therapy combined with anti-vascular endothelial growth factor (anti-VEGF) regimens showed new hope for cancer patients and considered as future pillar of cancer therapy. However, severe cutaneous adverse reactions (SCARs) in patients with ICIs and anti-VEGF combined therapy raise a serious concern and remain thoroughly assessed in clinics.

RESEARCH DESIGN AND METHODS

Data retrieved from the first quarter of 2004 to the third quarter of 2022 in FAERS database underwent disproportionality analysis and Bayesian analysis were utilized to detect and assess the SCAR signals of ICIs and ICIs and anti-VEGF combined therapy for comparison.

RESULTS

In total, 854 (1.10%) and 80 (1.06%) reports on SCARs associated with ICIs and a combination of ICIs and anti-VEGF therapy, respectively, were analyzed. Most of SCARs reports were associated with the use of pembrolizumab (36.01%), nivolumab (23.97%) and a combination of ipilimumab and nivolumab (19.71%). A use of atezolizumab and bevacizumab combined therapy (60.00%) caused the most SCARs records out of ICIs and anti-VEGF combined therapies.

CONCLUSIONS

Treatment with joint therapy of ICIs and anti-VEGF agents may cause severe cutaneous adverse events. It is vital to identify ICI-related SCARs early, and to manage them appropriately.

Clozapine and Sweet's syndrome: case report

A patient developed fever, raised inflammatory markers and a maculopapular rash following commencement of clozapine for treatment of his schizoaffective disorder. Skin biopsy confirmed Sweet's syndrome. Identification of the cause was challenging, with a number of possible considerations including infection, malignancy and various potential drug triggers.This case highlights the difficulties in the diagnosis of Sweet's syndrome, as well as in identifying the original trigger, which can have significant consequences for management. Withdrawal of potentially causative drugs must be balanced with their benefits, and decisions must be made in the best interests of the patient. Following two courses of prednisolone and withdrawal of clozapine, the patient's rash and systemic symptoms resolved. This confirmed the diagnosis of drug-induced Sweet's syndrome, with clozapine as the offending agent. His mental state stabilised on an alternative antipsychotic.

Case Report of Serum Sickness-like Reaction following the First Dose of the Chimpanzee Adenovirus-Vectored AstraZeneca COVID-19 Vaccine, ChAdOx1

Serum sickness-like reaction from serum sickness is critical. Serum sickness-like reaction has comparable symptoms to serum sickness, but their underlying pathophysiology is distinct. This delayed hypersensitivity response was first characterized as a drug-induced reaction and is uncommon in adults; it is more common in children. COVID-19 vaccinations are now being routinely given in the COVID-19 period, and adverse reactions to immunization have been recorded. We present a case of COVID-19 vaccination-induced serum sickness-like reaction which developed after receiving the first dose of AstraZeneca COVID-19 vaccine.

Advances in the Understanding of Drug Hypersensitivity: 2012 Through 2022

Over the last decade there have been key advances in understanding mechanisms, risk, and consequences of both true immunological drug hypersensitivity and unverified drug allergy labels that have changed clinical practice. This has been facilitated by the widespread adoption of electronic health records (EHRs). The vast majority of EHR drug allergy labels are unverified and cause significant morbidity from unnecessary avoidance of optimal drug therapy. There has also been significant movement in our understanding of mechanisms of drug hypersensitivity that, in addition to advancing our understanding of the pathogenesis of immediate and delayed reactions, have guided preventive efforts, diagnostic procedures, and clinical management. More widespread adoption, including scale-up of "allergy" delabeling and appropriate management, specifically for antibiotics, opiates, radiocontrast, chemotherapeutics, biologics, and nonsteroidal anti-inflammatory medications, will be necessary to improve patient outcomes over the next decade. This will require further engagement and collaboration between primary care health care providers, allergists, and other specialists.

Practical Implementation of Genetics: New Concepts in Immunogenomics to Predict, Prevent, and Diagnose Drug Hypersensitivity

Delayed drug hypersensitivities are CD8⁺ T cell-mediated reactions associated with up to 50% mortality. Human leukocyte antigen (HLA) alleles are known to predispose disease and are specific to drug, reaction, and patient ethnicity. Pretreatment screening is recommended for a handful of the strongest associations to identify and prevent drug use in high-risk patients. However, an incomplete predictive value implicates other HLA-imposed risk factors, and low carriage of many identified HLA-risk alleles combined with the high cost of sequence-based typing has limited economic viability for similar recommendation of screening across drugs and health care systems. For mitigation, an expanding armory of low-cost polymerase chain reaction-based screens is being developed, and HLA-imposed risk factors are being discovered. These include (1) polymorphic variants of metabolic and endoplasmic reticulum aminopeptidase enzymes toward multiallelic screening with increased predictivity; (2) regulation by immune checkpoint inhibitors, enabling detolerized animal models of human disease; and (3) immunodominant T cell receptors (TCR) on clonally expanded CD8⁺ T cells. For the latter, HLA risk-restricted TCR provides immunogenomic strategies and samples from a single patient to identify novel HLA-risk associations in underserved minority populations, tissue-relevant effector biomarkers toward earlier diagnosis and treatment, and HLA-TCR-presented immunogenic structures to aid future drug development.

Patch testing in Drug reaction with eosinophilia and systemic symptoms (DRESS): a literature review

The literature on positive patch test results in drug reaction with eosinophilia and systemic symptoms (DRESS) is reviewed. 105 drugs were identified that have together caused 536 positive patch tests in 437 patients suffering from DRESS. By far most reactions (n=145) were caused by carbamazepine, followed by amoxicillin, isoniazid, phenytoin, ethambutol, fluindione, phenobarbital, rifampicin, and ceftriaxone; 43 drugs each caused a single case only. The drug classes causing the highest number of reactions are anticonvulsants (39%), beta-lactam antibiotics (20%), antituberculosis agents (11%), non-beta-lactam antibiotics (6%) and iodinated contrast media (5%). The sensitivity of patch testing (percentage of positive reactions) is high for anticonvulsants (notably carbamazepine), beta-lactam antibiotics (notably amoxicillin) and possibly iodinated contrast media. Allopurinol and sulfasalazine frequently cause DRESS, but never give positive patch tests. Patch testing in DRESS appears to be safe, although mild recurrence of DRESS symptoms, mostly skin reactions, may not be rare. Multiple drug hypersensitivity was found to occur in 16% of all patients, but it is argued that the true frequency is (far) higher. Clinical aspects of DRESS, including diagnosing the disease and identifying culprit drugs (patch tests, intradermal tests, in vitro tests, challenge tests) are also provided, emphasizing the role of patch testing. This article is protected by copyright. All rights reserved.

Results of patch testing in Acute generalized exanthematous pustulosis (AGEP): a literature review

The literature on positive patch test results in acute generalized exanthematous pustulosis (AGEP) is reviewed. 93 drugs were identified that have together caused 259 positive patch tests in 248 patients suffering from AGEP. The drug classes causing the highest number of reactions are beta-lactam antibiotics (25.9%), other antibiotics (20.8%), iodinated contrast media (7.3%) and corticosteroids (5.4%), together accounting for nearly 60% of all reactions. The highest number of reactions to individual drugs was to amoxicillin (n=36), followed by pristinamycin (n=25), diltiazem (n=14), amoxicillin-clavulanic acid (n=13), clindamycin (n=11) and iomeprol (n=8); 59 of the 93 drugs each caused a single case only. The "Top-10" drugs together caused over 50% of all reactions. The sensitivity of patch testing (percentage of positive reactions) in patients with AGEP is largely unknown, but may generally be around 50%, which also applies to pristinamycin. Patch testing in AGEP appears to be safe, although mild recurrence of AGEP skin symptoms or other rashes may occur occasionally. Clinical aspects of AGEP, including epidemiology, etiology and pathophysiology, clinical features, histology, treatment, and prognosis are briefly presented, as are diagnosing the disease and identifying the culprit drugs with patch tests, intradermal tests, in vitro tests, and challenge tests. This article is protected by copyright. All rights reserved.

Use of Botulism Antitoxin Heptavalent (A, B, C, D, E, F, G)-(Equine) (BAT®) in Clinical Study Subjects and Patients: A 15-Year Systematic Safety Review

Botulism is a rare, sometimes fatal paralytic illness caused by botulinum neurotoxins. BAT^® (Botulism Antitoxin Heptavalent (A, B, C, D, E, F, G)—(Equine)) is an equine-derived heptavalent botulinum antitoxin indicated for the treatment of symptomatic botulism in adult and pediatric patients. This review assesses the cumulative safety profile for BAT product from 2006 to 2020, using data received from clinical studies, an expanded-access program, a post-licensure registry, spontaneous and literature reports. The adverse event (AE) incidence rate for BAT product was calculated conservatively using only BAT product exposures for individuals with a record (512) and was alternatively estimated using all BAT product exposure data, including post-licensure deployment information (1128). The most frequently reported BAT product-related AEs occurring in greater than 1% of the 512–1128 BAT product-exposed individuals were hypersensitivity, pyrexia, tachycardia, bradycardia, anaphylaxis, and blood pressure increase reported in 2.3–5.1%, 1.8–3.9%, 1.0–2.2%, 0.89–2.0%, 0.62–1.4%, and 0.62–1.4%, respectively. For patients properly managed in an intensive care setting, the advantages of BAT product appear to outweigh potential risks in patients due to morbidity and mortality of botulism. AEs of special interest, including bradycardia, hemodynamic instability, hypersensitivity, serum sickness, and febrile reactions in the registry, were specifically solicited.

Retrospective Study of Patients With SJS/TEN Treated at a Tertiary Burn Unit in Canada: Overview of 17 Years of Treatment

BACKGROUND

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are adverse drug reactions.

OBJECTIVES

To learn about the clinical characteristics of patients with SJS/TEN including treatments provided, outcomes, and mortality.

METHODS

We conducted a retrospective chart review of patients who were hospitalized with the diagnosis of SJS/TEN at the Ross Tilley Burn Center between the years 1999 and 2015.

RESULTS

A total of 43 patients were identified with a mean age of 54 ± 19 (58, 18-85). The most common offending medications were allopurinol and carbamazepine. The overall mortality rate in our study is 21% with the most common causes of death being multiorgan failure and sepsis. The majority of our patients had oral (84%), ocular (79%), and genital (60%) involvement during hospitalization. Our data revealed that combination treatment involving oral corticosteroids with intravenous immunoglobulin (IVIG) had the highest mortality rate in our study since 55% (6/11) of patients who were treated in this manner passed away compared to 11% (2/18) of patients passing away who were treated with solely IVIG and 33% (1/3) who were treated with only supportive care. Our study also demonstrates the addition of etanercept and cyclosporine treatment in the second time period we studied: 2008-2015 versus the earlier time period of 1999-2007. None of the patients in our study who were treated with therapies including cyclosporine and/or etanercept passed away.

CONCLUSIONS

Our study sheds light on a possible beneficial role of cyclosporine and etanercept for the treatment of SJS and TEN and reinforces the necessity of a multidisciplinary care team for patients.

Practical guide for evaluation and management of beta-lactam allergy: position statement from the Canadian Society of Allergy and Clinical Immunology

The vast majority of individuals labelled as allergic are not deemed truly allergic upon appropriate assessment by an allergist. A label of beta-lactam allergy carries important risks for individual and public health. This article provides an overview of beta-lactam allergy, implications of erroneous beta-lactam allergy labels and the impact that can be provided by structured allergy assessment. We provide recommendations on how to stratify risk of beta-lactam allergy, beta lactam challenge protocols as well as management of patients at high risk of beta-lactam allergy.

Serum sickness-like reactions in Iranian children: a registry-based study in a referral center

INTRODUCTION AND OBJECTIVES

Considering that no studies have been done on a comprehensive review of Serum sickness-like reactions patients (SSLRs) at a referral center in Iran so far, this study aimed to determine the clinical and laboratory characteristics of children with SSRL in Tehran Children's Medical Center.

PATIENTS

The present study was a registry-based study in which the data of 94 SSLRs patients registered in a two-year period were investigated. Confirmation of fever, rash, urticaria, arthralgia / arthritis and history of antibiotic consumption up to three weeks before were the criteria for the diagnosis.

RESULTS

Fifty-one (54 %) patients were male with mean age of 56 ± 30 months and there was no significant difference in the age of the two genders. The mean onset of symptoms before hospitalization were 3.8 ± 2.7 days (1-14 days); this mean was significantly higher in males than in females (4.6 ± 2.9 versus 2.9 ± 1.7 days, P-value = 0.003). Among antibiotics, Co-amoxiclav and Cefixime antibiotics had the most frequency by 31 % and 33 %, respectively as the most important incidence factor of SSLRs. The mean duration of consumption of culprit medications in the incidence of SSLRs was 5.6 ± 2.9 days with a range of 1-15 days.

CONCLUSIONS

This study showed that among the antibiotics, Co-amoxiclav and Cefixime are more prevalent and a review of prescribing these two antibiotics for the treatment of the children's infections is essential if this finding is confirmed by other Iranian scholars.

Epidemiology and Risk Factors for Severe Delayed Drug Hypersensitivity Reactions

Severe delayed drug hypersensitivity reactions comprise different clinical entities and can involve different immune-mediated mechanisms. Common examples are severe cutaneous adverse reactions and druginduced internal organ injuries. The incidence of such reactions is overall low but seems to be on the rise reaching numbers as high as 9 per million individuals-years in the case of SJS/TEN and DRESS. Such conditions carry an important associated morbidity, and mortality can attain 40% in SJS/TEN patients, making these hypersensitivity reactions important targets when implementing preventive measures. Several risk factors have been identified for reaction severity; some are transverse, such as older age and underlying chronic diseases. The recent advances in pharmacogenetics allowed the identification of specific populations with higher risk and permitted strategic avoidance of certain drugs being HLA-B*57:01 screening in patients initiating abacavir the best successful example. In this work, we reviewed the epidemiology of SCARs and liver/kidney/lung drug-induced immune-mediated reactions. We focus on particular aspects such as prevalence and incidence, drugs involved, mortality and risk factors.

An Interesting Case of Carbamazepine-Induced Stevens-Johnson Syndrome

A 29-year-old Black female patient was admitted to a psychiatric ward with symptoms of major depressive disorder with psychosis. The patient was started on amitriptyline 50 mg/day and haloperidol 10 mg/day. On day 4 post-admission, the preferred first-line antidepressant, fluoxetine, became available and the patient was switched from amitriptyline to fluoxetine 20 mg/day. On the same day, the dose of haloperidol was reduced to 5 mg/day. Thirteen days post-initiation of these medications the patient became talkative, associated with emotional lability, an expansive mood, irritability and restlessness. The working diagnosis was changed to bipolar affective disorder in the manic phase. Fluoxetine was discontinued and carbamazepine 600 mg/day was added to the patient's treatment regimen. Her manic symptoms started to resolve; however, 14 days post-initiation of carbamazepine, the patient had a fever; itchy, discharging eyes; respiratory distress; generalised symmetrical erythematosus rash; buccal ulceration; and conjunctival injection with difficulty opening her eyes. Carbamazepine was immediately discontinued and the patient received intravenous fluid resuscitation. The patient recovered considerably after 12 days of symptomatic and supportive management, and was transferred back to the psychiatric ward for the continuation of bipolar disorder management. Lithium therapy was instituted and the patient was subsequently discharged. Using the Algorithm of Drug causality for Epidermal Necrolysis (ALDEN) Stevens-Johnson Syndrome/toxic epidermal necrolysis (SJS/TEN) drug causality scoring system, carbamazepine and fluoxetine were evaluated as 'very probable' and 'possible' causes of SJS, respectively, in this patient. Fluoxetine-induced SJS was considered on account of previous case reports, however no evidence of causality was found in this patient. Consecutive administration with a potential increase in carbamazepine due to inhibition of cytochrome P450 (CYP) 3A4 metabolism by fluoxetine was also not ruled out. A diagnosis of carbamazepine-induced SJS was made and was considered an idiosyncratic adverse drug reaction.

Identification of Inpatient Allergic Drug Reactions Using ICD-9-CM Codes

BACKGROUND

The study of allergic drug reactions has been limited because of challenges in identifying and confirming cases.

OBJECTIVE

To determine the utility of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for identifying inpatient allergic drug reactions and to compare findings with previous data in the emergency department.

METHODS

By reviewing medical records of inpatients with ICD-9-CM codes and E codes suggestive of allergic drug reactions at a large urban academic medical center, we determined codes that yielded the most drug allergy cases and identified culprit drugs.

RESULTS

In 2005 and 2010, 3337 and 5282 possible allergic drug reactions during hospitalization were identified and 1367 were reviewed. Allergic drug reactions were found in 409 (30.1%) of the reviewed charts, with 172 (29.7%) in 2005 and 237 (30.5%) in 2010. The codes that identified the highest percentage of true allergic drug reactions were dermatitis due to drug (693.0), allergic urticaria (708), angioneurotic edema (995.1), and anaphylaxis (995.0). Antibiotics were the most common cause (44.4%); however, multiple drug classes were often identified as likely culprit drugs.

CONCLUSION

Specific ICD-9-CM codes can identify patients with allergic drug reactions, with antibiotics accounting for almost half of true reactions. Most patients with codes 693.0, 995.1, 708, and 995.0 had allergic drug reactions, with 693.0 as the highest yield code. An aggregate of multiple specific codes consistently identifies a cohort of patients with confirmed allergic drug reactions.

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.

Stevens-Johnson Syndrome Associated With Chlordiazepoxide

Objective: To report a case of chlordiazepoxide-associated Stevens-Johnson syndrome (SJS). Case Summary: This case provides insight into a serious adverse drug reaction secondary to a drug not commonly associated with SJS. A 29-year-old female presented with a 4-day history of rash and pruritus. The rash started on her arms and spread all over her body. The patient was started on chlordiazepoxide 3½ weeks ago. On examination, there were multiple, raised, round erythematous lesions in various stages of healing. Skin erosions were noted on her lips and buccal mucosa. However, the rash did not involve the conjunctiva, inner ears, or genitalia. The patient was discharged home with a follow-up appointment with dermatology and instructions to discontinue chlordiazepoxide. Two days after her initial presentation, the patient's rash spread to her eyes and genitalia. A painful, white film developed on her tongue, and she was unable to tolerate oral intake. She was emergently sent back to hospital and transferred to a Burn Unit. The biopsy report revealed full-thickness necrotizing keratinocytes in the epidermis consistent with SJS. Discussion: To our knowledge, there is only one other case report of chlordiazepoxide-associated SJS. Chlordiazepoxide is thought to be the cause of this patient's biopsy-confirmed SJS and overall presentation. SJS is a rare but serious condition that is usually a result of drug exposure. Conclusions: The close temporal relationship between chlordiazepoxide initiation and onset of SJS provides a convincing theory as to the etiology of SJS in our patient.

Severe Cutaneous Adverse Drug Reactions: Presentation, Risk Factors, and Management

PURPOSE OF STUDY

Immune-mediated adverse drug reactions occur commonly in clinical practice and include mild, self-limited cutaneous eruptions, IgE-mediated hypersensitivity, and severe cutaneous adverse drug reactions (SCAR). SCARs represent an uncommon but potentially life-threatening form of delayed T cell-mediated reaction. The spectrum of illness ranges from acute generalized exanthematous pustulosis (AGEP) to drug reaction with eosinophilia with systemic symptoms (DRESS), to the most severe form of illness, Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

RECENT FINDINGS

There is emerging literature on the efficacy of cyclosporine in decreasing mortality in SJS/TEN. The purpose of our review is to discuss the typical presentations of these conditions, with a special focus on identifying the culprit medication. We review risk factors for developing SCAR, including HLA alleles strongly associated with drug hypersensitivity. We conclude by discussing current strategies for the management of these conditions.

SJS/TEN 2017: Building Multidisciplinary Networks to Drive Science and Translation

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a life-threatening, immunologically mediated, and usually drug-induced disease with a high burden to individuals, their families, and society with an annual incidence of 1 to 5 per 1,000,000. To effect significant reduction in short- and long-term morbidity and mortality, and advance clinical care and research, coordination of multiple medical, surgical, behavioral, and basic scientific disciplines is required. On March 2, 2017, an investigator-driven meeting was held immediately before the American Academy of Dermatology Annual meeting for the central purpose of assembling, for the first time in the United States, clinicians and scientists from multiple disciplines involved in SJS/TEN clinical care and basic science research. As a product of this meeting, this article summarizes the current state of knowledge and expert opinion related to SJS/TEN covering a broad spectrum of topics including epidemiology and pharmacogenomic networks; clinical management and complications; special populations such as pediatrics, the elderly, and pregnant women; regulatory issues and the electronic health record; new agents that cause SJS/TEN; pharmacogenomics and immunopathogenesis; and the patient perspective. Goals include the maintenance of a durable and productive multidisciplinary network that will significantly further scientific progress and translation into prevention, early diagnosis, and management of SJS/TEN.

Severe Delayed Cutaneous and Systemic Reactions to Drugs: A Global Perspective on the Science and Art of Current Practice

Most immune-mediated adverse drug reactions (IM-ADRs) involve the skin, and many have additional systemic features. Severe cutaneous adverse drug reactions (SCARs) are an uncommon, potentially life-threatening, and challenging subgroup of IM-ADRs with diverse clinical phenotypes, mechanisms, and offending drugs. T-cell-mediated immunopathology is central to these severe delayed reactions, but effector cells and cytokines differ by clinical phenotype. Strong HLA-gene associations have been elucidated for specific drug-SCAR IM-ADRs such as Stevens-Johnson syndrome/toxic epidermal necrolysis, although the mechanisms by which carriage of a specific HLA allele is necessary but not sufficient for the development of many IM-ADRs is still being defined. SCAR management is complicated by substantial short- and long-term morbidity/mortality and the potential need to treat ongoing comorbid disease with related medications. Multidisciplinary specialist teams at experienced units should care for patients. In the setting of SCAR, patient outcomes as well as preventive, diagnostic, treatment, and management approaches are often not generalizable, but rather context specific, driven by population HLA-genetics, the pharmacology and genetic risk factors of the implicated drug, severity of underlying comorbid disease necessitating ongoing treatments, and cost considerations. In this review, we update the basic and clinical science of SCAR diagnosis and management.

Stevens-Johnson syndrome and toxic epidermal necrolysis: a review

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are uncommon, acute and potentially life-threatening adverse cutaneous drug reactions. These pathologies are considered a hypersensitivity reaction and can be triggered by drugs, infections and malignancies. The drugs most often involved are allopurinol, some antibiotics, including sulfonamides, anticonvulsants such as carbamazepine, and some non-steroid anti-inflammatory drugs (NSAIDs). Necrosis of keratinocytes is manifested clinically by epidermal detachment, leading to scalded skin appearance. The rash begins on the trunk with subsequent generalization, usually sparing the palmoplantar areas. Macular lesions become purplish, and epidermal detachment occurs, resulting in flaccid blisters that converge and break, resulting in extensive sloughing of necrotic skin. Nikolsky's sign is positive in perilesional skin. SJS and TEN are considered to be two ends of the spectrum of one disease, differing only by their extent of skin detachment. Management of patients with SJS or TEN requires three measures: removal of the offending drug, particularly drugs known to be high-risk; supportive measures and active interventions. Early diagnosis of the disease, recognition of the causal agent and the immediate withdrawal of the drug are the most important actions, as the course of the disease is often rapid and fatal.

Adverse Medication Reactions

Cutaneous adverse drug reactions (ADRs) are among the most frequent adverse reactions in patients receiving drug therapy. They have a broad spectrum of clinical manifestations, are caused by various drugs, and result from different pathophysiological mechanisms. Hence, their diagnosis and management is challenging.

Severe cutaneous ADRs comprise a group of diseases with major morbidity and mortality, reaching 30 % mortality rate in cases of Toxic Epidermal Necrolysis.

This chapter covers the terminology, epidemiology, pathogenesis and classification of cutaneous ADR, describes the severe cutaneous ADRs and the clinical and laboratory approach to the patient with cutaneous ADR and presents the translation of laboratory-based discoveries on the genetic predisposition and pathogenesis of cutaneous ADRs to clinical management guidelines.

Adverse Drug Reactions of the Lower Extremities

Adverse drug reactions (ADRs) are a common cause of dermatologic consultation, involving 2 to 3 per 100 medical inpatients in the United States. Female patients are 1.3 to 1.5 times more likely to develop ADRs, except in children less than 3 years of age, among whom boys are more often affected. Certain drugs are more frequent causes, including aminopenicillins, trimethoprim-sulfamethoxazole, and nonsteroidal antiinflammatory drugs. Chemotherapeutic agents commonly cause adverse reactions to the skin and nails, with certain agents causing particular patterns of reactions. ADRs can involve any area of the skin; the appendages, including hair and nails; as well as mucosa.

CD4+ T cell responses in Balb/c mice with food allergy induced by trinitrobenzene sulfonic acid and ovalbumin

The rapid increase in atopic diseases is potentially linked to increased hapten exposure, however, the role of haptens in the pathogenesis of food allergy remains unknown. Further studies are required to elucidate the cluster of differentiation 4 positive (CD4+) T cell response to food allergy induced by haptens. Dendritic cells were primed by trinitrobenzene sulfonic acid (TNBS) as a hapten or ovalbumin (OVA) as a model antigen, in a cell culture model. BALB/c mice were sensitized using TNBS and/or OVA. Intestinal Th1/Th2 cell and ovalbumin specific CD4+ T cells proliferation, intestinal cytokines (interleukin‑4 and interferon‑γ) in CD4+ T cells were evaluated. TNBS increased the expression of T cell immunoglobulin and mucin domain‑4 and tumor necrosis factor ligand superfamily member 4 in dendritic cells. Skewed Th2 cell polarization, extensive expression of interleukin‑4, reduced expression of interferon‑γ and forkhead box protein P3 were elicited following concomitant exposure to TNBS and OVA, with reduced regulatory T cells in the mouse intestinal mucosa, whereas a Th1 response was detected when challenged by TNBS or OVA alone. This data suggests that TNBS, as a hapten, combined with food antigens may lead to a Th2 cell response in the intestinal mucosa.

Immediate and non-immediate allergic reactions to amoxicillin present a diagnostic dilemma: a case series

Background

Allergic reactions to amoxicillin are very common occurrences in the pediatric age group; however, onset of symptoms can present a diagnostic dilemma.

Case presentation

We present a case series that describes three children (8-year-old white girl, 2-year-old white boy and 14-month-old Chinese boy) who presented with varied onset of allergic reactions to amoxicillin, specifically immediate (within the first hour after exposure) and non-immediate onset. One child developed immediate onset allergy to oral challenge with amoxicillin although his clinical history was evident for non-immediate onset allergy to amoxicillin. He was the only case that had a positive skin test to penicillin. Two other children presented with reactions toward the end of their treatment course of amoxicillin, yet one patient developed immediate onset allergy while the other patient developed non-immediate onset allergy after challenge.

Conclusions

This case series demonstrates diagnostic challenges facing physicians assessing allergic reactions to amoxicillin. As onset of reactions can dictate severity and pathogenic type of allergy, a thorough clinical history and subsequent appropriate diagnostic testing including medication challenge can help establish the diagnosis.

Approach to the Patient with a Suspected Cutaneous Adverse Drug Reaction

CADRs are common and generally have a mild, self-resolving course with minimal associated morbidity and mortality. However, subsets of CARDs are more severe, require intervention, and have significant risk of associated morbidity and mortality. For this reason, it is crucial that the clinician recognize signs and symptoms worrisome for a more severe CARD so that appropriate triage, work-up, and treatment are initiated. In all CADRs the most important first step is identification and withdrawal of the culprit medications.

Stevens Johnson Syndrome and Toxic Epidermal Necrolysis: Maternal and Foetal Outcomes in Twenty-Two Consecutive Pregnant HIV Infected Women

Introduction

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) form a spectrum of a rare and life-threatening cutaneous drug reaction. SJS/TEN in pregnancy poses largely unknown risk factors and outcomes for both the mother and foetus compared to the general population.

Methods

We conducted a study of consecutive pregnant women admitted to single tertiary referral centre in South Africa with SJS/TEN over a 3 year period. They were all managed by the same medical team using the same protocols. We evaluated their underlying illnesses, offending drugs and the course of pregnancy and outcomes to determine factors influencing maternal and foetal outcomes.

Results

We identified twenty-two women who developed SJS/TEN while pregnant, all of them HIV-infected. Their median age was 29 years. The majority 16/22 (73%) had SJS, the milder variant of the disease affecting < 10% body surface area. Nevirapine was the offending drug in 21/22 (95%) cases. All 22 of the mothers survived with 3/22 (14%) developing postpartum sepsis. Pregnancy outcomes were known in 18/22 women and 9/18 (50%) babies were delivered by caesarean section. There were 2 foetal deaths at 21 and 31 weeks respectively and both were associated with post-partum sepsis. Postnatal complications occurred in 5 cases, 3 involving the respiratory system and the other two being low birth weight deliveries. Eight placentae and one foetus were sent for histology and none showed macroscopic or microscopic features of SJS/TEN. On follow-up, only 12/20 children were tested for HIV at 6 weeks post-delivery and none of them were HIV-infected. All had received prophylactic ARVs including nevirapine.

Conclusions

TEN, the severe form of the disease, was associated with poorer foetal outcomes. SJS/TEN-associated mortality is not increased in HIV-infected pregnant women. Maternal SJS/TEN does not seem to commonly manifest in the foetus.