Role of air pollutants mediated oxidative stress in respiratory diseases.

Airborne particulate (PM) components from fossil fuel combustion can induce oxidative stress initiated by reactive oxygen species (ROS) that are strongly correlated with airway inflammation and asthma. A valid biomarker of airway inflammation is fractionated exhaled nitric oxide (FENO). The oxidative potential of PM2.5 can be evaluated with the dithiothreitol (DTT) dosage, which represents both ROS chemically produced and intracellular ROS of macrophages. This correlates with quality indicators of the internal environment and ventilation strategies such as dilution and removal of airborne contaminants.

Hypersensitivity reactions to vaccines in children: from measles to SARS-CoV-2.

Allergic individuals at risk for hypersensitivity reactions to measles vaccine marketed for a long time are well established. On the other hand, risk factors for hypersensitivity reactions to the new mRNA COVID-19 vaccines currently include a history of allergy, allergy to excipient of the vaccine, or hypersensitivity reactions to the first dose of COVID-19 vaccine. In the last two cases, the recipient should be assessed by an allergist before vaccination to share a decision on the choice of vaccination. Studies on skin testing accuracy and desensitization protocols to the COVID-19 vaccines and the efficacy of potential alternatives in patients with confirmed hypersensitivity reactions to the first COVID-19 vaccine are necessary to improve the safety of COVID-19 vaccines.

Radiocontrast Media Hypersensitivity Reactions in Children.

Hypersensitivity reactions to radiocontrast media seem to be rare in children. Furthermore, the use of radiocontrast media in children remains quite safe in terms of the severity of reactions. Since pediatric guidelines are lacking, the diagnostic workup employed in adults could be adapted to children, taking into account that results have not yet been validated in this age group. Specific protocols for risk stratification and management of severe reactions have been proposed so far.

Hypersensitivity reactions to proton pump inhibitors in childhood.

Hypersensitivity reactions (HRs) to proton pump inhibitors (PPIs) are mainly described in adults. Anyway, increased use of PPIs in childhood has been observed in recent years. In the literature, only case reports are published on children. Most of the PPI HRs are IgE-mediated. Skin test concentrations and allergy workup protocols used for adults are also applied in children. This study underlies that multicentric pediatric studies focusing on PPI reactions in children are needed.

Hypersensitivity Reactions to Monoclonal Antibodies in Children.

Biologic drugs are widely used in pediatric medicine. Monoclonal antibodies (mAbs) in particular are a therapeutic option for rheumatic, autoinflammatory and oncologic diseases. Adverse drug reactions and hypersensitivity reactions (HSR) to mAbs may occur in children. Clinical presentation of HSRs to mAbs can be classified according to phenotypes in infusion-related reactions, cytokine release syndrome, both alpha type reactions and type I (IgE/non-IgE), type III, and type IV reactions, all beta-type reactions. The aim of this review is to focus on HSRs associated with the most frequent mAbs in childhood, with particular attention to beta-type reactions. When a reaction to mAbs is suspected a diagnostic work-up including in-vivo and in-vitro testing should be performed. A drug provocation test is recommended only when no alternative drugs are available. In selected patients with immediate IgE-mediated drug allergy a desensitization protocol is indicated. Despite the heavy use of mAbs in childhood, studies evaluating the reliability of diagnostic test are lacking. Although desensitization may be effective in reducing the risk of reactions in children, standardized pediatric protocols are still not available.

Skin tests are important in children with ß-lactam hypersensitivity, but may be reduced in number.

BACKGROUND: There is no perfect agreement on how to perform an allergy workup in suspected beta-lactam (BL)-allergic children, since skin test (ST)-induced pain is often a limitation. The aim of the study was to assess the possibility of reducing the number of ST in children when performing a complete allergy workup for BL hypersensitivity reactions. METHODS: A retrospective analysis of all patients referring to the Allergy Unit of the University Hospital of Montpellier (France) with positive responses in immediateand non-immediate-reading ST to a BL over a 16-year period was performed, to determine the positive predictive value (PPV) of ST. All pediatric patients with a suspected BL hypersensitivity were skin-tested with the suspected drug only, during the following 54 months. RESULTS: A total of 319 patients reporting 328 BL reactions were included in the retrospective study. The PPV of ST for the reported drug was of 99.4%. Based on the results, the number of patients to include in the prospective study was estimated to be 101. In the prospective study, 229 children were included. We diagnosed a BL hypersensitivity in 12 children (5.2%): Diagnosis was reached in 6 (50.0%) through ST (delayed reading for all) and in 6 through drug provocation test (DPT). CONCLUSION: ST with BL should therefore be performed as a screening test, before DPT, and testing only the suspected drug may be sufficient when dealing with children.

Clinical use of basophil activation test in drug, food and hymenoptera venom allergies.

The basophil activation is emerging as a reliable and robust in vitro biomarker of in vivo allergy reactions. Basophil Activation Test (BAT), intended as in vitro stimulation of patient blood basophil with allergens, followed by flow cytometric detection and quantification of such activation, is nowadays a well-established assay in a growing number of routine diagnostic labs. The advancements in the standardization of BAT testing and first convincing clinical evidence are behind this spreading of the assay in clinical lab. BAT is essentially an assay with superior specificity compared to any other allergy testing and, if appropriately used, it can have a valuable clinical utility in different field of allergy diagnosis. In drug allergy, very few testing opportunities are available for the numbers of drugs actually in the market. Antibiotics and analgesics are just two of the categories of drugs were BAT testing can have an added value for the limited specificity of IgE testing or limited availability of other lab testing. In food allergy, BAT is emerging as the more accurate assay to predict an in vivo reaction to food, helping in the discrimination of patients that are only sensitized versus the patient really allergic to an allergen. Furthermore, BAT testing determining the basophil sensitivity can be useful for monitoring the natural resolution of allergies and clinical responses to immunomodulatory treatment for food allergies. For this characteristic, BAT has the potential to reduce the need of OFC. In the hymenoptera venom allergy, BAT is an effective tool in identifying primary sensitizing antigen and in the follow up of patient in venom immunotherapy. With this review, we want to present current state of BAT testing focusing on the clinical laboratory parameters and issue of this assay. A highlight on the standardization needs of BAT is provided, together with considerations on further developments and clinical evidences still to be achieved.

Evaluating children with suspected allergic reactions to vaccines for infectious diseases.

BACKGROUND: Vaccines often contain potentially allergenic material in addition to pathogen-specific immunogens that may induce allergic reactions. Parents and physicians often suspect that adverse reactions to vaccines are allergic in etiology. The concern that some of the substances contained in vaccines may trigger an anaphylactic reaction may lead to a low vaccination adherence with emergence of infectious disease epidemics. OBJECTIVE: To provide practical suggestions for managing children suspected to have an allergic reaction to a vaccine. METHODS: Information was obtained from a search of guidelines and relevant studies on allergic reactions to vaccines for infectious diseases. RESULTS: True allergic reactions elicited by a vaccine are rare. Skin testing to the vaccine and to its components may identify the triggering agent. Graded dosing desensitization is helpful in children sensitized to the offending vaccine. CONCLUSION: All children with a suspected allergic reaction to a vaccine should be carefully evaluated by routine allergy tests. When it is necessary, further immunization should be given under strict medical surveillance, which ensures that every child can safely complete the vaccination schedule.

A new pediatric protocol for rapid desensitization to monoclonal antibodies.

Monoclonal antibodies are important therapeutic tools, but their usefulness may be limited when patients experience acute hypersensitivity reactions. Patients reporting a history of adverse allergic reaction are likely to discontinue their therapeutic protocol or be switched to an alternative drug, which is sometimes less effective than that originally prescribed. Drug desensitization has proven to be a highly effective strategy to readminister a drug in a patient who has experienced a hypersensitivity reaction. It involves forcing the patient's immune system to accept and tolerate the allergen. Nevertheless, such a procedure is still empiric for monoclonal antibodies and not common in the pediatric population. The aim of our study is to demonstrate the clinical success of a new protocol of rapid desensitization to infliximab in a pediatric patient affected by ulcerative colitis, who developed an anaphylaxis to the drug. We used a protocol of rapid desensitization consisting of 13 steps, with the first being 1/1,000,000 of the cumulative and total dose. Such a protocol has proven to be able to induce a temporary tolerance to infliximab, allowing the patient to achieve complete control of his disease.

Adenoids in children: Advances in immunology, diagnosis, and surgery.

Adenoids are strategically located for mediating local and regional immune functions as they are exposed to antigens from both the outside air and the alimentary tract. Recurrent or chronic respiratory infections can induce histomorphological and functional changes in the adenoidal immunological barrier, sometimes making surgical treatment necessary. Our aim in this review is to summarize the crucial points about not only the immunological histopathology of adenoidal tissue, especially in patients with adenoid hypertrophy, but also the most common and useful diagnostic techniques and surgical options.

Local Anesthetic Hypersensitivity Reactions in Pediatric Patients: Recognition and Management.

Local anesthetics (LAs) are commonly used in all medical specialties, particularly in association with surgery, obstetrics, dentistry, and emergency departments. Most individuals, starting from young children, are exposed to LAs during life. LA hardly induces adverse events when used in recommended doses and with proper injection techniques. However, immediate anaphylactic reactions to LA injections may be a rare but life-threatening manifestation. A comprehensive report of the event and performing a specialist examination are crucial to prevent further episodes. The diagnosis should be based on history, medical records, skin and challenge tests.

Drug-Induced Anaphylaxis in Children.

Drug-induced anaphylaxis in children is less common than in adults and primarily involves beta-lactams and nonsteroidal anti-inflammatory drugs. Epidemiological studies show variable prevalence, influenced by age, gender, and atopic diseases. The pathophysiology includes IgE-mediated reactions and non-IgE mechanisms, like cytokine release reactions. We address drug-induced anaphylaxis in children, focusing on antibiotics, nonsteroidal anti-inflammatory drugs, neuromuscular blocking agents, and monoclonal antibodies. Diagnosis combines clinical criteria with in vitro, in vivo, and drug provocation tests. The immediate management of acute anaphylaxis primarily involves the use of adrenaline, coupled with long-term strategies, such as allergen avoidance and patient education. Desensitization protocols are crucial for children allergic to essential medications, particularly antibiotics and chemotherapy agents.

Invasive Streptococcal Infection in Children: An Italian Case Series.

Since October 2022, alerts have spread from several countries about the increase in invasive group A streptococcal (iGAS) and scarlet fever cases affecting young children. We aim to analyze the epidemiology of GAS infections in the last 12 years in our hospital and identify the clinical features of invasive cases observed in 2023. We conducted a retrospective study enrolling children and adolescents hospitalized at our pediatric clinic from January to December 2023 for a definitive diagnosis of iGAS infection. Clinical, laboratory, and imaging data were collected and analyzed. Comparing 2016 and 2023, we observed a similar number of GAS infections (65 vs. 60 cases). Five children with iGAS infection were hospitalized between March and April 2023. The median age was five years. At admission, all patients showed tachycardia disproportionate to their body temperature. Vomiting was a recurrent symptom (80%). Laboratory tests mostly showed lymphopenia, hyponatremia, and high inflammatory markers. The number of pediatric iGAS cases significantly increased in 2023. Clinical (pre-school-aged children with high fever, unexplained tachycardia, and vomiting) and laboratory parameters (high procalcitonin levels, hyponatremia, and lymphopenia) could help identify and suspect a potential iGAS infection.

Record of strep throat infections in Italy: what is needed to know about penicillin allergy? The point of view from the Italian Society of Pediatric Allergy and Immunology (SIAIP).

Notifications of invasive group A streptococcal (iGAS) infections have significantly increased in many European Countries compared to the previous season. In Italy, there has been an increase in streptococcal pharyngitis and scarlet fever cases since January 2023, which sparked concerns about a GAS epidemic in the pediatric population. This rise may be ascribed to the GAS infection season that began earlier than usual (off-season outbreak) and the increase in the spread of respiratory viruses and viral coinfections that raised the risk of iGAS disease. Moreover, this phenomenon was also facilitated by increased travel after reduced GAS circulation during the COVID-19 pandemic.The increase in cases of GAS disease has raised some critical issues regarding the potential reactions to administering amoxicillin, the first-line antibiotic therapy, many of which have been erroneously labeled as "allergy."For these reasons, the Italian Society of Pediatric Allergy and Immunology (SIAIP) intends to provide simple clinical indications to help pediatricians manage GAS pharyngitis, discerning the allergic from non-allergic drug hypersensitivity.

Diagnostic Delay of Celiac Disease in Childhood.

Importance: The extent and factors associated with risk of diagnostic delay in pediatric celiac disease (CD) are poorly understood. Objectives: To investigate the diagnostic delay of CD in childhood, and to assess factors associated with this delay. Design, Setting, and Participants: Multicenter, retrospective, cross-sectional study (2010-2019) of pediatric (aged 0-18 years) patients with CD from 13 pediatric tertiary referral centers in Italy. Data were analyzed from January to June 2023. Main Outcomes and Measures: The overall diagnostic delay (ie, the time lapse occurring from the first symptoms or clinical data indicative of CD and the definitive diagnosis), further split into preconsultation and postconsultation diagnostic delay, were described. Univariable and multivariable linear regression models for factors associated with diagnostic delay were fitted. Factors associated with extreme diagnostic delay (ie, 1.5 × 75th percentile) and misdiagnosis were assessed. Results: A total of 3171 patients with CD were included. The mean (SD) age was 6.2 (3.9) years; 2010 patients (63.4%) were female; and 10 patients (0.3%) were Asian, 41 (1.3%) were Northern African, and 3115 (98.3%) were White. The median (IQR) overall diagnostic delay was 5 (2-11) months, and preconsultation and postconsultation diagnostic delay were 2 (0-6) months and 1 (0-3) month, respectively. The median (IQR) extreme overall diagnostic delay (586 cases [18.5%]) was 11 (5-131) months, and the preconsultation and postconsultation delays were 6 (2-120) and 3 (1-131) months, respectively. Patients who had a first diagnosis when aged less than 3 years (650 patients [20.5%]) showed a shorter diagnostic delay, both overall (median [IQR], 4 [1-7] months for patients aged less than 3 years vs 5 [2-12] months for others) and postconsultation (median [IQR], 1 [0-2] month for patients aged less than 3 years vs 2 [0-4] months for others). A shorter delay was registered in male patients, both overall (median [IQR], 4 [1-10] months for male patients vs 5 [2-12] months for female patients) and preconsultation (median [IQR], 1 [0-6] month for male patients vs 2 [0-6] months for female patients). Family history of CD was associated with lower preconsultation delay (odds ratio [OR], 0.59; 95% CI, 0.47-0.74) and lower overall extreme diagnostic delay (OR, 0.75; 95% CI, 0.56-0.99). Neurological symptoms (78 patients [21.5%]; OR, 1.35; 95% CI, 1.03-1.78), gastroesophageal reflux (9 patients [28.1%]; OR, 1.87; 95% CI, 1.02-3.42), and failure to thrive (215 patients [22.6%]; OR, 1.62; 95% CI, 1.31-2.00) showed a more frequent extreme diagnostic delay. A previous misdiagnosis (124 patients [4.0%]) was more frequently associated with gastroesophageal reflux disease, diarrhea, bloating, abdominal pain, constipation, fatigue, osteopenia, and villous atrophy (Marsh 3 classification). Conclusions and Relevance: In this cross-sectional study of pediatric CD, the diagnostic delay was rather short. Some factors associated with risk for longer diagnostic delay and misdiagnosis emerged, and these should be addressed in future studies.

Endoscopic Treatment for Nonhypertrophic Idiopathic Pyloric Stenosis in an Adolescent Patient.

Nonhypertrophic idiopathic pyloric stenosis (NHIPS) is a rare occurrence in children. It could be related to peptic ulcers, but a definitive cause is yet to be found. Treatment is a matter of debate, ranging from medical to surgical. We report the case of a 15-year-old boy suffering postprandial vomiting and weight loss in the previous 3 months. NHIPS was diagnosed and successfully treated with several sessions of endoscopic pyloric dilation and jejunal feeding. In association with a multidisciplinary approach, endoscopic dilation should be considered as a first-line treatment to avoid surgery.

Eosinophilic Gastrointestinal Diseases in Inborn Errors of Immunity.

Inborn errors of immunity (IEI) are disorders mostly caused by mutations in genes involved in host defense and immune regulation. Different degrees of gastrointestinal (GI) involvement have been described in IEI, and for some IEI the GI manifestations represent the main and characteristic clinical feature. IEI also carry an increased risk for atopic manifestations. Eosinophilic gastrointestinal diseases (EGIDs) are emerging disorders characterized by a chronic/remittent and prevalent eosinophilic inflammation affecting the GI tract from the esophagus to the anus in the absence of secondary causes of intestinal eosinophilia. Data from the U.S. Immunodeficiency Network (USIDNET) reported that EGIDs are more commonly found in patients with IEI. Considering this element, it is reasonable to highlight the importance of an accurate differential diagnosis in patients with IEI associated with mucosal eosinophilia to avoid potential misdiagnosis. For this reason, we provide a potential algorithm to suspect an EGID in patients with IEI or an IEI in individuals with a diagnosis of primary EGID. The early diagnosis and detection of suspicious symptoms of both conditions are fundamental to prevent clinically relevant complications.

A Practical Update on Pediatric Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an emerging atopic disease of unknown etiology limited to the esophagus. The pathogenesis is still understood and is likely characterized by type 2 inflammation. Food allergens are the primary triggers of EoE that stimulate inflammatory cells through an impaired esophageal barrier. In children and adolescents, clinical presentation varies with age and mainly includes food refusal, recurrent vomiting, failure to thrive, abdominal/epigastric pain, dysphagia, and food impaction. Upper-gastrointestinal endoscopy is the gold standard for diagnosing and monitoring EoE. EoE therapy aims to achieve clinical, endoscopic, and histological ("deep") remission; prevent esophageal fibrosis; and improve quality of life. In pediatrics, the cornerstones of therapy are proton pump inhibitors, topical steroids (swallowed fluticasone and viscous budesonide), and food elimination diets. In recent years, much progress has been made in understanding EoE pathogenesis, characterizing the clinical and molecular heterogeneity, and identifying new therapeutic approaches. Notably, clinical, molecular, endoscopic, and histological features reflect and influence the evolution of inflammation over time and the response to currently available treatments. Therefore, different EoE phenotypes and endotypes have recently been recognized. Dupilumab recently was approved by FDA and EMA as the first biological therapy for adolescents (≥12 years) and adults with active EoE, but other biologics are still under consideration. Due to its chronic course, EoE management requires long-term therapy, a multidisciplinary approach, and regular follow-ups.

Evaluation of diagnostic time in pediatric patients with eosinophilic gastrointestinal disorders according to their clinical features.

Eosinophilic gastrointestinal disorders (EGIDs) are chronic/remittent inflammatory diseases associated with a substantial diagnostic delay, often attributable to misdiagnosis and variable clinical presentation in adults. In the pediatric population, few studies have been conducted worldwide reporting EGID diagnostic delay and its consequences on patients. This study aims to analyze and identify potential clinical factors and complications associated with a longer diagnostic time. We performed a retrospective analysis of pediatric patients with EGIDs followed at the Center for Pediatric EGIDs in Pavia, Italy. A total of 60 patients with EGIDs were enrolled. Thirty-nine (65%) patients had EoE, and 21 (35%) non-esophageal EGIDs. EGID diagnosis was achieved about 2 years after the symptom onset, and the median diagnostic time was 12 months (IQR 12-24 months). Diagnostic time was 12 months (IQR 12-69) in non-esophageal EGIDs and 12 months (IQR 4-24 months) in EoE patients. EoE patients presenting with FTT and feeding issues experienced a longer diagnostic time (p = 0.02 and p = 0.05, respectively) than children without growth and feeding impairments.In this study, symptoms appeared about 2 years before the definitive EGID diagnosis was reached, and this diagnostic time was shorter than the delay observed in other published studies. Especially in EoE children, the diagnostic time is significantly associated with impaired child growth, highlighting the importance of an early diagnosis to prevent esophageal stenosis and failure to thrive.

How can we better classify NSAID hypersensitivity reactions?--validation from a large database.

BACKGROUND: Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) is one of the most common drug hypersensitivities. Several clinical subtypes have been distinguished depending on symptomatology (respiratory, cutaneous, anaphylaxis), timing (immediate, delayed), underlying chronic disease (asthma, chronic urticaria) or putative mechanism of the reaction (allergic, nonallergic mediated). The aim of the present study was to better classify the many hypersensitivity reactions to NSAIDs. METHODS: In the present retrospective study, during an 11-year study period, we collected data from all patients with a proven NSAID hypersensitivity. Reactions were classified according to clinical patterns, chronology, underlying diseases and the results of oral provocation tests into 5 and 7 groups in line with two published classifications, respectively. RESULTS: Forty-nine and 88 out of 307 reactions (in 122 patients) could not be classified on the basis of the two previously published classifications. We created a new classification which could include all patient reactions. CONCLUSIONS: Our new classification is more suitable for clinical expression of NSAID hypersensitivity. It allows clinicians to identify patients at a high risk, based on the clinical history and clinical manifestations. Moreover, it is helpful for a better understanding and teaching of these reactions.