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Food Challenges

There are many tools that can help suggest the presence of food allergies, but, in the end, the most reliable procedure to confirm or exclude a diagnosis of food allergy remains the oral challenge.  But how should allergists perform them?  In this month’s issue of JACI, Drs. Ballmer-Weber and Beyer provide their insights on how to effectively conduct a food challenge ( J Allergy Clin Immunol 2018; 141(1): 69-71 ).   The majority of children with food allergies require such challenges to diagnose their condition, especially younger children with eczema who have skin prick or blood tests suggesting that allergic sensitization may be a trigger for eczema flares, or in whom a food allergy may no longer be present.  However, not all patients should have challenges.  The risks of a severe, life-threatening anaphylactic reaction have to be balanced with the benefits of more definitively establishing a diagnosis.  In addition, the risks of an oral challenge ma...

Food allergy: Update on prevention and tolerance

The rate of food allergies in the United States keeps on rising, but nobody really knows the exact reasons why.  In this month’s issue of the Journal of Allergy and Clinical Immunology, Du Toit and colleagues review the literature and focus on the ‘dual allergen’ hypothesis ( J Allergy Clin Immunol 2018; 141(1): 30-40 ).  Briefly, they explain that allergic sensitization may occur when there is low-level skin exposure to food allergens, while tolerance is more likely to develop in children to have early exposures to food proteins.  The data are mounting from both animal and human observational studies as well as randomized control studies.  The most notable has been the LEAP study, which showed that infants aged 4 to 11 months who consumed peanut products at least three times per week until age 60 months were far less likely to develop peanut allergies than infants who had complete avoidance.  Only 3.2% in the peanut-eating group developed peanut allergy, compar...

Can we predict fall asthma exacerbations? Validation of the seasonal asthma exacerbation index

Asthma affects about 1 in 11 American children, making it one of the most common diseases of childhood.  It carries a huge burden on families, especially during exacerbations when disease activity suddenly flares, leading to breathlessness and even death.  In this month’s issue of JACI, Hoch and colleagues discuss their research in validating the Seasonal Asthma Exacerbation Predictive Index, the saEPI ( J Allergy Clin Immunol 2017; 140(4): 1130-1137 ).  The saEPI is a score ranging from 0 to 16 that can help predict how likely a child is to have an asthma flare.  Using data from the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations (PROSE) study, they looked at 348 children randomized to two groups: one with omalizumab, and another with guideline-based therapy alone.  They then calculated and validated the saEPI, moreover the authors looked at other factors that were associated with exacerbations.  In short, they found that children who req...

Role of viral infections in the development and exacerbation of asthma in children

Wheezing is a common complaint among parents of infants.  About 1 in 5 children have acute wheezing illnesses in their first two years of life.  This is important because an overwhelming majority of these wheezing illnesses are related to viruses, and are linked to asthma development.  In this month’s issue of JACI, Jartti and Gern review the role of viral infections in the development of asthma in children ( J Allergy Clin Immunol 2017; 140(4): 895-906 ).  They survey the viruses -rhinoviruses, respiratory syncytial viruses, and others – and how they impact the developing set of lungs.  Genetic variation and low interferon responses are two factors that increase the risk of these types of infections.  In addition, increased eosinophil counts in blood and nasal mucus and atopic eczema all increase the risk of later asthma.  Additionally, viral infections can lead to exacerbations in children who already have asthma.  This may explain why the rates...

Promising approaches for the treatment and prevention of viral respiratory illnesses

There are hundreds of viruses that cause respiratory tract infections.  While most of us think about them as nuisances causing cough and wheezing, they bear a huge toll on health, especially in people who have lung diseases like asthma and COPD, as well as an economic toll in lost workdays and inappropriate use of medical resources.  In this month’s issue of JACI, Papadopoulos and colleagues look at the treatment and prevention of these diseases ( J Allergy Clin Immunol 2017; 140(4): 921-932 ).  They look at new medications that target the specific viruses in their reproductive phases.  In addition, they review how natural products like echinacea can prevent recurrent respiratory tract infections.  On the other side, there are promising insights about the use of immunostimulators in order to boost the body’s own responses to these viruses.  Vitamin D, probiotic supplements, exercise and meditation are all helpful in resolving these infections. But perhaps t...

Diagnostic accuracy of fractional exhaled nitric oxide in predicting cough variant asthma and eosinophilic bronchitis in adult patients with chronic cough: A systematic review and meta-analysis

Cough is an important reflex we need to remove irritants from the airways, but for many people, a hypersensitive cough reflex can negatively affect quality of life.  A major trigger of chronic cough is airway inflammation from immune cells including type 2 helper T-cells (T H 2), but conventional tests required for diagnosis are technically challenging and often require specialist expertise.  Fortunately, measurement of the fractional exhaled nitric oxide (FENO), a potential marker of T H 2 airway inflammation, has become much more common in allergy and pulmonary practices.  In this month’s issue of JACI, Song and colleagues review the literature on the use of FENO to diagnose Cough-Variant Asthma (CVA) and Eosinophilic Bronchitis (EB), two major causes of T H 2-mediated chronic cough ( J Allergy Clin Immunol 2017; 140(3): 701-709 ). They looked at thousands of articles from multiple databases in order to answer the question “What is the diagnostic accuracy of FENO for CV...

Identification of airway mucosal type 2 inflammation by using clinical biomarkers in asthmatic patients

Asthma is a complex disease of the airways characterized by inflammation and dynamic airway obstruction.  Despite the single, more recent evidence suggests that asthma is mediated by a set of distinct immune abnormalities.  In this month’s issue of JACI, Silkoff and colleagues report the results of the ADEPT (Airways Disease Endotyping for Personal Therapeutics) study, in which 83 patients with mild, moderate, and severe asthma as well as 25 healthy non-asthmatic subjects were examined for biomarkers of asthma ( J Allergy Clin Immunol 2017; 140(3): 710-719 ).  They underwent bronchoscopy to obtain tissue samples, and then had the biomarkers measured in the lab to characterize them as having either high or low levels of type 2 inflammatory mediators.  These were then correlated with clinical variables. They determined the presence of type 2 inflammation based on airway expression of CCL26, periostin, and IL-13 in vitro signature (IVS).  They then looked at the cl...