Megan S. Motosue

Vitamin D and food allergies in children: A systematic review and meta-analysis

BACKGROUND Vitamin D insufficiency has been associated with immune dysfunction and linked to the epidemic of atopic diseases in the Western hemisphere, yet there are studies with conflicting results, and the risk has not been quantified uniformly across studies. OBJECTIVE To perform a systematic review and meta-analysis to evaluate and quantify if vitamin D deficiency is associated with the presence and persistence of food allergy. METHODS A systematic review was undertaken to assess for the association between food allergy and vitamin D status in children. RESULTS A total of 368 citations relevant to this systematic review were identified. In the whole review, 5105 children were included. We did not find a significant association between 25 hydroxy vitamin D (25(OH)D) status and risk of food allergy in children (odds ratio [OR] 1.35 [95% confidence interval {CI}, 0.79-2.29]; p = 0.27, I2 = 58.3%). We conducted subgroup analyses based on different cutoffs of the 25(OH)D status (20 versus 30 ng/mL). Only one study used 30 ng/mL and found that children with <30 ng/mL were more likely to report food allergy than children with a 25(OH)D status of ≥30 ng/mL (OR 2.04 [95% CI, 1.02-4.04]; p = 0.04). Four studies compared children with a 25(OH)D status of <20 ng/mL to children with a 25(OH)D status of ≥20 ng/mL and found no significant differences (OR 1.18 [95% CI, 0.62-2.27]; p = 0.62, I2 = 62.7%). CONCLUSION Based on the studies analyzed, this systematic review did not identify a significant association between vitamin D status and food allergy. Interpretation of the included studies was limited by a lack of a standard definition for vitamin D deficiency and insufficient knowledge regarding the optimal vitamin D status needed to impact immune function. Longitudinal studies are warranted to assess if vitamin D might contribute to the development of food allergy.

Risk factors for severe anaphylaxis in the United States

BACKGROUND Anaphylaxis is an acute systemic allergic reaction and may be life-threatening. OBJECTIVE To assess risk factors associated with severe and near-fatal anaphylaxis in a large observational cohort study. METHODS We analyzed administrative claims data from Medicare Advantage and privately insured enrollees in the United States from 2005 to 2014. Severe anaphylaxis was defined as anaphylaxis resulting in hospital or intensive care unit (ICU) admission, requiring endotracheal intubation, or meeting criteria for near-fatal anaphylaxis. RESULTS Of 38,695 patients seen in the emergency department for anaphylaxis during the study period, 4,431 (11.5%) required hospitalization, 2,057 (5.3%) were admitted to the ICU, 567 (1.5%) required endotracheal intubation, and 174 (0.45%) were classified as having a near-fatal episode. Multivariable analysis revealed that medication-related anaphylaxis (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.38-1.63; P < .001), age of 65 years or older (OR, 3.15; 95% CI, 2.88-3.44; P < .001), and the presence of cardiac disease (OR, 1.56; 95% CI, 1.50-1.63; P < .001) or lung disease (OR, 1.23; 95% CI, 1.16-1.30; P < .001) were associated with increased odds of severe anaphylaxis requiring any hospital admission, ICU admission, or intubation or being a near-fatal reaction. CONCLUSION In this large contemporary cohort study, 11.6% of patients had severe anaphylaxis. Age of 65 years or older, medication as a trigger, and presence of comorbid conditions (specifically cardiac and lung disease) were associated with significantly higher odds of severe anaphylaxis. Additional studies examining risk factors for severe anaphylaxis are needed to define risk assessment strategies and establish a framework for management.

Risk factors for recurrent anaphylaxis-related emergency department visits in the United States

BACKGROUND Anaphylaxis is a potentially life-threatening allergic reaction with a strong risk of recurrence. OBJECTIVE To assess risk factors associated with recurrent anaphylaxis-related emergency department (ED) visits within 1 year of an ED visit for anaphylaxis in a large observational cohort study. METHODS We used an administrative claims database to identify patients seen from 2008 through 2012 in the ED for anaphylaxis based on an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code algorithm. Patients with at least 2 years of continuous enrollment in a health plan were included. Multivariable logistic regression analysis was used to determine associations with recurrence of anaphylaxis within 1 year. RESULTS During the 5-year study period, 7,367 patients (median age, 42 years; <18 years old, 23.3%) met the inclusion criteria. The most common anaphylaxis trigger was unspecified (56.2%), followed by food (25.3%), medication (14.6%), and venom (3.9%). Overall, 3.0% of patients had an additional anaphylaxis-related ED visit within 1 year (3.61 episodes per 100 patient-years). On multivariable analysis, risk factors associated with anaphylaxis recurrence were food trigger (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.34-3.99), history of asthma (OR, 1.30; 95% CI, 1.13-1.51), and intensive care unit admission at the index anaphylaxis event (OR, 1.95; 95% CI, 1.41-2.69). CONCLUSION In this contemporary cohort study, history of asthma, food trigger, and greater index anaphylaxis severity, as measured by intensive care unit admission, were associated with a higher likelihood of a recurrent anaphylaxis-related ED visit within 1 year.