Food Allergy

Purpose of Review

The goal of this review is to present an updated summary of the natural history of major childhood and adult food allergies and report recent advances in potential treatments for food allergy.

Recent Findings

The most common childhood food allergies are typically outgrown by adolescence or adulthood. However, peanut/tree nut allergies appear to more commonly persist into adulthood. Adults can develop new IgE-mediated food allergies; the most common is oral allergy syndrome. There are multiple different approaches being tried as possible treatments for food allergy.

Summary

The prevalence of food allergy appears to be increasing but the varied approaches to treatment are being actively pursued such that an approved modality may not be too far in the future.

     

Social Media and Obesity in Adults: a Review of Recent Research and Future Directions

Purpose of Review

Social media is widely used and has potential to connect adults with obesity with information and social support for weight loss and to deliver lifestyle interventions. The purpose of this review is to summarize recent observational and intervention research on social media and obesity.

Recent Findings

Online patient communities for weight loss abound but may include misinformation. Systematic reviews and meta-analyses suggest that social media-delivered lifestyle interventions modestly impact weight, yet how social media was used and participant engagement varies widely.

Summary

The rapidly changing social media landscape poses challenges for patients, clinicians, and researchers. Research is needed on how patients can establish supportive communities for weight loss and the role of clinicians in these communities. Emerging research on meaningful engagement in, and the efficacy and cost-effectiveness of, social media-delivered lifestyle interventions should provide insights into how to leverage social media to address the obesity epidemic.

     

The Genetics of Food Allergy

Purpose of Review

Food allergy likely arises from a complex interplay between environmental triggers and genetic susceptibility. Here, we review recent studies that have investigated the genetic pathways and mechanisms that may contribute to the pathogenesis of food allergy.

Recent Findings

A heritability component of food allergy has been observed in multiple studies. A number of monogenic diseases characterized by food allergy have elucidated pathways that may be important in pathogenesis. Several population-based genetic variants associated with food allergy have also been identified.

Summary

The genetic mechanisms that play a role in the development of food allergy are heterogeneous and complex. Advances in our understanding of the genetics of food allergy, and how this predisposition interacts with environmental exposures to lead to disease, will improve our understanding of the key pathways leading to food allergy and inform more effective prevention and treatment strategies.

     

Interaction Between Allergy and Middle Ear Infection

Purpose of Review

Recent studies have attempted to identify interactions among the causes of otitis media with effusion (OME). This review discusses the interaction between allergy and infection with regard to host and environmental factors in terms of the development of OME.

Recent Findings

Protection of the upper airway against microbial invasion requires active interaction between the defense mechanisms of the respiratory epithelium, including innate and adaptive immunity, and mechanical factors. The impairment of these defenses due to allergy and/or increased bacterial resistance may lead to increased susceptibility to infectious organisms in the respiratory tract and middle ear mucosa. Recent genetic studies have provided valuable information about the association of Toll-like receptor signaling variations with clinical phenotypes and the risk of infection in the middle ear.

Summary

Among the causal factors of OME, allergy not only induces an inflammatory reaction in the middle ear cavity but also facilitates the invasion of infectious pathogens. There is also evidence that allergy can affect the susceptibility of patients to infection of the upper respiratory tract, including the middle ear cavity.

     

Cancer Risk Communication with Low Health Literacy Patients: A Continuing Medical Education Program

BACKGROUND

Low health literacy (HL) is an important risk factor for cancer health disparities.

OBJECTIVE

Describe a continuing medical education (CME) program to teach primary care physicians (PCP) cancer risk communication and shared decision-making (SDM) with low HL patients and baseline skills assessment.

DESIGN

Cluster randomized controlled trial in five primary care clinics in New Orleans, LA.

PARTICIPANTS

Eighteen PCPs and 73 low HL patients overdue for cancer screening.

INTERVENTION

Primary care physicians completed unannounced standardized patient (SP) encounters at baseline. Intervention physicians received SP verbal feedback; academic detailing to review cancer screening guidelines, red flags for identifying low HL, and strategies for effective counseling; and web-based tutorial of SP comments and checklist items hyperlinked to reference articles/websites.

MAIN MEASURES

Baseline PCP self-rated proficiency, SP ratings of physician general cancer risk communication and SDM skills, patient perceived involvement in care.

RESULTS

Baseline assessments show physicians rated their proficiency in discussing cancer risks and eliciting patient preference for treatment/decision-making as “very good”. SPs rated physician exploration of perceived cancer susceptibility, screening barriers/motivators, checking understanding, explaining screening options and associated risks/benefits, and eliciting preferences for screening as “satisfactory”. Clinic patients rated their doctor’s facilitation of involvement in care and information exchange as “good”. However, they rated their participation in decision-making as “poor”.

DISCUSSION

The baseline skills assessment suggests a need for physician training in cancer risk communication and shared decision making for patients with low HL. We are determining the effectiveness of teaching methods, required resources and long-term feasibility for a CME program.

     

Role of the Microbiome in Food Allergy

Purpose of Review

Resident microbial communities likely modify risk for allergic disorders, including food allergy. We review epidemiologic studies linking microbial exposures to food allergy risk and discuss the mechanisms by which the microbiome may modulate oral tolerance. We additionally address ongoing translational efforts in human microbiome studies.

Recent Findings

Epidemiologic studies and murine models support that altered microbial exposures and colonization in early life modify food allergy risk. Differential microbiota confer protection or susceptibility to food allergy by modulating the regulatory tone of the mucosal immune system. Recent efforts are focused on the identification of bacterial strains necessary for oral tolerance in human and microbial-based clinical trials.

Summary

Early childhood appears to be critical for the colonization of a diverse microbiota necessary for the induction and maintenance of oral tolerance. Identification and functional evaluation of protective commensal microbes will inform strategies for the prevention and treatment of food allergy.

     

Food Allergies Caused by Allergenic Lipid Transfer Proteins: What Is behind the Geographic Restriction?

Purpose of Review

To critically examine evidence suggesting that food allergy induced by lipid transfer proteins (LTPs) follows a geographic pattern.

Recent Findings

LTP syndrome remains most common in the Mediterranean basin, with a clear gradient seen in prevalence of LTP sensitization between northern and southern Europe. We hypothesize that high levels of birch pollen seem to protect against LTP allergy, as these higher levels correlate with a lower prevalence of LTP hypersensitivity. Nevertheless, LTP food allergy cases still appear in areas having a high environmental level of birch pollen.

Summary

Food allergy caused by LTP may be related to (1) primary sensitization to a food LTP allergen in the absence of pollinosis, (2) primary sensitization to LTP from a pollen source, and (3) co-sensitization to LTP from pollen and food.

     

Mast Cell Interactions and Crosstalk in Regulating Allergic Inflammation

Purpose of Review

This review summarizes recent findings on mast cell biology with a focus on IgE-independent roles of mast cells in regulating allergic responses.

Recent Findings

Recent studies have described novel mast cell-derived molecules, both secreted and membrane-bound, that facilitate cross-talk with a variety of immune effector cells to mediate type 2 inflammatory responses.

Summary

Mast cells are complex and dynamic cells that are persistent in allergy and are capable of providing signals that lead to the initiation and persistence of allergic mechanisms.

     

Applying Systems Engineering Principles in Improving Health Care Delivery

Background

In a highly publicized joint report, the National Academy of Engineering and the Institute of Medicine recently recommended the systematic application of systems engineering approaches for reforming our health care delivery system. For this to happen, medical professionals and managers need to understand and appreciate the power that systems engineering concepts and tools can bring to redesigning and improving health care environments and practices.

Objective

To present and discuss fundamental concepts and tools of systems engineering and important parallels between systems engineering, health services, and implementation research as it pertains to the care of complex patients.

Design

An exploratory, qualitative review of systems engineering concepts and overview of ongoing applications of these concepts in the areas of hemodialysis, radiation therapy, and patient flow modeling.

Results

In this paper, we describe systems engineering as the process of identifying the system of interest, choosing appropriate performance measures, selecting the best modeling tool, studying model properties and behavior under a variety of scenarios, and making design and operational decisions for implementation.

Conclusions

We discuss challenges and opportunities for bringing people with systems engineering skills into health care.

     

Multimethod Evaluation of the VA’s Peer-to-Peer Toolkit for Patient-Centered Medical Home Implementation

BACKGROUND

Effective implementation of the patient-centered medical home (PCMH) in primary care practices requires training and other resources, such as online toolkits, to share strategies and materials. The Veterans Health Administration (VA) developed an online Toolkit of user-sourced tools to support teams implementing its Patient Aligned Care Team (PACT) medical home model.

OBJECTIVE

To present findings from an evaluation of the PACT Toolkit, including use, variation across facilities, effect of social marketing, and factors influencing use.

INNOVATION

The Toolkit is an online repository of ready-to-use tools created by VA clinic staff that physicians, nurses, and other team members may share, download, and adopt in order to more effectively implement PCMH principles and improve local performance on VA metrics.

DESIGN

Multimethod evaluation using: (1) website usage analytics, (2) an online survey of the PACT community of practice’s use of the Toolkit, and (3) key informant interviews.

PARTICIPANTS

Survey respondents were PACT team members and coaches (n?=?544) at 136 VA facilities. Interview respondents were Toolkit users and non-users (n?=?32).

MEASURES

For survey data, multivariable logistic models were used to predict Toolkit awareness and use. Interviews and open-text survey comments were coded using a “common themes” framework. The Consolidated Framework for Implementation Research (CFIR) guided data collection and analyses.

KEY RESULTS

The Toolkit was used by 6,745 staff in the first 19 months of availability. Among members of the target audience, 80 % had heard of the Toolkit, and of those, 70 % had visited the website. Tools had been implemented at 65 % of facilities. Qualitative findings revealed a range of user perspectives from enthusiastic support to lack of sufficient time to browse the Toolkit.

CONCLUSIONS

An online Toolkit to support PCMH implementation was used at VA facilities nationwide. Other complex health care organizations may benefit from adopting similar online peer-to-peer resource libraries.

     

Sulfonamide Drug Allergy

Purpose of Review

We sought to review past and current literature on sulfonamide drug allergy and distill it in a practical manner to assist the clinician, specifically focusing on cross-reactivity and desensitization.

Recent Findings

There do not appear to be consistent genetic markers to reliably predict features of or the presence hypersensitivity reactions. Recent evidence continues to alleviate early concerns cross-reactivity between sulfonamide antibiotics and non-antibiotics.

Summary

Sulfonamide drug allergy is frequently encountered by the practicing clinician. For sulfonamide antibiotics, delayed rash is the most common clinical manifestation. There is no current evidence to support avoidance of all non-antibiotic sulfonamides in those with a reported allergy to sulfonamide antibiotics, although certain scenarios require caution. Available evidence supports the cautious reintroduction of sulfonamide antibiotics via desensitization, which is usually well tolerated and should be considered in those with strong indications for trimethoprim-sulfamethoxazole and a reported sulfonamide allergy.

     

Prediction Model for Two-Year Risk of Opioid Overdose Among Patients Prescribed Chronic Opioid Therapy

Background

Naloxone is a life-saving opioid antagonist. Chronic pain guidelines recommend that physicians co-prescribe naloxone to patients at high risk for opioid overdose. However, clinical tools to efficiently identify patients who could benefit from naloxone are lacking.

Objective

To develop and validate an overdose predictive model which could be used in primary care settings to assess the need for naloxone.

Design

Retrospective cohort.

Setting

Derivation site was an integrated health system in Colorado; validation site was a safety-net health system in Colorado.

Participants

We developed a predictive model in a cohort of 42,828 patients taking chronic opioid therapy and externally validated the model in 10,708 patients.

Main Measures

Potential predictors and outcomes (nonfatal pharmaceutical and heroin overdoses) were extracted from electronic health records. Fatal overdose outcomes were identified from state vital records. To match the approximate shelf-life of naloxone, we used Cox proportional hazards regression to model the 2-year risk of overdose. Calibration and discrimination were assessed.

Key Results

A five-variable predictive model showed good calibration and discrimination (bootstrap-corrected c-statistic?=?0.73, 95% confidence interval [CI] 0.69–0.78) in the derivation site, with sensitivity of 66.1% and specificity of 66.6%. In the validation site, the model showed good discrimination (c-statistic?=?0.75, 95% CI 0.70–0.80) and less than ideal calibration, with sensitivity and specificity of 82.2% and 49.5%, respectively.

Conclusions

Among patients on chronic opioid therapy, the predictive model identified 66–82% of all subsequent opioid overdoses. This model is an efficient screening tool to identify patients who could benefit from naloxone to prevent overdose deaths. Population differences across the two sites limited calibration in the validation site.

     

Defining Appropriate Use of Proton-Pump Inhibitors Among Medical Inpatients

BACKGROUND

Proton-pump inhibitors (PPIs) are commonly used among medical inpatients, both for prophylaxis against upper gastrointestinal bleeding (UGIB) and continuation of outpatient use. While PPIs reduce the risk of UGIB, they also appear to increase the risk of hospital-acquired pneumonia (HAP) and Clostridium difficile infection (CDI). Depending upon the underlying risks of these conditions and the changes in those risks with PPIs, use of proton-pump inhibitors may lead to a net benefit or net harm among medical inpatients.

OBJECTIVE

We aimed to determine the net impact of PPIs on hospital mortality among medical inpatients.

DESIGN

A microsimulation model, using literature-derived estimates of the risks of UGIB, HAP, and CDI among medical inpatients, along with the changes in risk associated with PPI use for each of these outcomes. The primary outcome was change in inpatient mortality.

PARTICIPANTS

Simulated general medical inpatients outside the intensive care unit (ICU).

MAIN MEASURE

Change in overall mortality during hospitalization.

KEY RESULTS

New initiation of PPI therapy led to an increase in hospital mortality in about 90 % of simulated patients. Continuation of outpatient PPI therapy on admission led to net increase in hospital mortality in 79 % of simulated patients. Results were robust to both one-way and multivariate sensitivity analyses, with net harm occurring in at least two-thirds of patients in all scenarios.

CONCLUSIONS

For the majority of medical inpatients outside the ICU, use of PPIs likely leads to a net increase in hospital mortality. Even in patients at particularly high risk of UGIB, only those at the very lowest risk of HCAP and CDI should be considered for prophylactic PPI use. Continuation of outpatient PPIs may also increase expected hospital mortality. Apart from patients with active UGIB, use of PPIs in hospitalized patients should be discouraged.

     

CURB-65 Score is Equal to NEWS for Identifying Mortality Risk of Pneumonia Patients: An Observational Study

Importance

The CURB-65 score is widely implemented as a prediction tool for identifying patients with community-acquired pneumonia (cap) at increased risk of 30-day mortality. However, since most ingredients of CURB-65 are used as general prediction tools, it is likely that other prediction tools, e.g. the British National Early Warning Score (NEWS), could be as good as CURB-65 at predicting the fate of CAP patients.

Objective

To determine whether NEWS is better than CURB-65 at predicting 30-day mortality of CAP patients.

Design

This was a single-centre, 6-month observational study using patients’ vital signs and demographic information registered upon admission, survival status extracted from the Danish Civil Registration System after discharge and blood test results extracted from a local database.

Setting

The study was conducted in the medical admission unit (MAU) at the Hospital of South West Jutland, a regional teaching hospital in Denmark.

Participants

The participants consisted of 570 CAP patients, 291 female and 279 male, median age 74 (20–102) years.

Results

The CURB-65 score had a discriminatory power of 0.728 (0.667–0.789) and NEWS 0.710 (0.645–0.775), both with good calibration and no statistical significant difference.

Conclusion

CURB-65 was not demonstrated to be significantly statistically better than NEWS at identifying CAP patients at risk of 30-day mortality.

     

Occupational Animal Allergy

Purpose of Review

This review explores animal allergen exposure in research laboratories and other work settings, focusing on causes and prevention.

Recent Findings

(1) Consistent with the hygiene hypothesis, there is new evidence that early childhood exposure to pets produces changes in the gut microbiome that likely lead to a lower risk of allergy. (2) Anaphylaxis from laboratory animal bites occurs more frequently than suggested by prior literature. (3) Animal allergens represent an occupational hazard in a wide variety of work settings ranging from fields that work with animals to public settings like schools and public transportation where allergens are brought into or are present in the workplace.

Summary

Exposure to animal allergens can result in allergy, asthma, and anaphylaxis. Animal allergy has been most studied in the research laboratory setting, where exposure reduction can prevent the development of allergy. Similar prevention approaches need to be considered for other animal work environments and in all settings where animal allergens are present.

     

Post-transplantation Development of Food Allergies

Purpose of Review

The development of food allergies is increasingly being recognized as a post-solid organ transplant complication. In this article, we review the spectrum of post-transplant food allergy development and the proposed mechanisms for de novo food allergies and the clinical significance they pose.

Recent Findings

The development of new food allergies is disproportionately associated with pediatric liver transplants, where it occurs in up to 38% of select populations. The mechanism of food allergy development is not completely understood; however, it is likely promoted by unbalanced immune suppression.

Summary

De novo food allergy development is a common complication of solid organ transplants with the highest risk occurring in pediatric liver transplant recipients. There are likely multiple mechanisms for food allergy development including passive transfer of membrane-bound IgE and lymphocytes from donor to recipient, as well as loss of food tolerance and active development of new food allergies. The optimal management of food allergies following organ transplants has not been well researched but may include changing the immune suppression regimen if the food allergy does not resolve without intervention.

     

Next-Generation of Allergen-Specific Immunotherapies: Molecular Approaches

Purpose of Review

The aim of this article is to discuss how allergen-specific immunotherapy (AIT) can be improved through molecular approaches. We provide a summary of next-generation molecular AIT approaches and of their clinical evaluation. Furthermore, we discuss the potential of next generation molecular AIT forms for the treatment of severe manifestations of allergy and mention possible future molecular strategies for the secondary and primary prevention of allergy.

Recent Findings

AIT has important advantages over symptomatic forms of allergy treatment but its further development is limited by the quality of the therapeutic antigen preparations which are derived from natural allergen sources. The field of allergy diagnosis is currently undergoing a dramatic improvement through the use of molecular testing with defined, mainly recombinant allergens which allows high-resolution diagnosis. Several studies demonstrate that molecular testing in early childhood can predict the development of symptomatic allergy later on in life.

Summary

Clinical studies indicate that molecular AIT approaches have the potential to improve therapy of allergic diseases and may be used as allergen-specific forms of secondary and eventually primary prevention for allergy.