Kirsten M. Kloepfer

Detection of pathogenic bacteria during rhinovirus infection is associated with increased respiratory symptoms and asthma exacerbations

BACKGROUND Detection of either viral or bacterial pathogens is associated with wheezing in children; however, the influence of both bacteria and viruses on illness symptoms has not been described. OBJECTIVE We evaluated bacterial detection during the peak rhinovirus season in children with and without asthma to determine whether an association exists between bacterial infection and the severity of rhinovirus-induced illnesses. METHODS Three hundred eight children (166 with asthma and 142 without asthma) aged 4 to 12 years provided 5 consecutive weekly nasal samples during September and scored cold and asthma symptoms daily. Viral diagnostics and quantitative PCR for Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were performed on all nasal samples. RESULTS Detection rates were 53%, 17%, and 11% for H influenzae, S pneumoniae, and M catarrhalis, respectively, with detection of rhinovirus increasing the risk of detecting bacteria within the same sample (odds ratio [OR], 2.0; 95% CI, 1.4-2.7; P < .0001) or the following week (OR, 1.6; 95% CI, 1.1-2.4; P = .02). In the absence of rhinovirus, S pneumoniae was associated with increased cold symptoms (mean, 2.7 [95% CI, 2.0-3.5] vs 1.8 [95% CI, 1.5-2.2]; P = .006) and moderate asthma exacerbations (18% [95% CI, 12% to 27%] vs 9.2% [95% CI, 6.7% to 12%]; P = .006). In the presence of rhinovirus, S pneumoniae was associated with increased moderate asthma exacerbations (22% [95% CI, 16% to 29%] vs 15% [95% CI, 11% to 20%]; P = .01). Furthermore, M catarrhalis detected alongside rhinovirus increased the likelihood of experiencing cold symptoms, asthma symptoms, or both compared with isolated detection of rhinovirus (OR, 2.0 [95% CI, 1.0-4.1]; P = .04). Regardless of rhinovirus status, H influenzae was not associated with respiratory symptoms. CONCLUSION Rhinovirus infection enhances detection of specific bacterial pathogens in children with and without asthma. Furthermore, these findings suggest that M catarrhalis and S pneumoniae contribute to the severity of respiratory tract illnesses, including asthma exacerbations.

Increased H1N1 Infection Rate in Children with Asthma

RATIONALE The 2009 H1N1 flu appeared to cause more severe cold symptoms during the 2009-2010 flu season. OBJECTIVES We evaluated H1N1 infections during peak viral season in children with and without asthma to determine whether the H1N1 infectivity rate and illness severity were greater in subjects with asthma. METHODS One hundred and eighty children, 4-12 years of age, provided eight consecutive weekly nasal mucus samples from September 5 through October 24, 2009, and scored cold and asthma symptoms daily. Viral diagnostics were performed for all nasal samples. MEASUREMENTS AND MAIN RESULTS One hundred and sixty-one children (95 with asthma, 66 without asthma) completed at least 6 of the 8 nasal samples. The incidence of H1N1 infection was significantly higher in children with asthma (41%) than in children without asthma (24%; odds ratio, 4; 95% confidence interval, 1.8-9; P < 0.001), but rates of human rhinovirus infection (90% each) and other viral infections (47 vs. 41%) were similar. In children with asthma, there was a nonsignificant trend for increased loss of asthma control during H1N1 infections compared with human rhinovirus infections (38 vs. 21%; odds ratio, 2.6; 95% confidence interval, 0.9-7.2; P = 0.07). CONCLUSIONS During peak 2009 H1N1 flu season, children with asthma were infected almost twice as often with H1N1 compared with other respiratory viruses. H1N1 infection also caused increased severity of cold symptoms compared with other viral infections. Given the increased susceptibility of children with asthma to infection, these findings reinforce the need for yearly influenza vaccination to prevent infection, and raise new questions about the mechanism for enhanced susceptibility to influenza infection in asthma.

Virus/Allergen Interactions and Exacerbations of Asthma

Clinical research findings indicate that there are synergistic interactions between allergy and viral infection that cause increased severity of asthma exacerbations. This article summarizes the current literature linking these 2 risk factors for asthma exacerbation, and reviews experimental data suggesting potential mechanisms for interactions between viral infection and allergy that cause asthma exacerbations. In addition, the authors discuss clinical evidence that treatment of allergic inflammation could help to reduce the frequency and severity of virus-induced exacerbations of asthma.

In children, the microbiota of the nasopharynx and bronchoalveolar lavage fluid are both similar and different

Sputum and bronchoalveolar lavage fluid (BALF) are often obtained to elucidate the lower airway microbiota in adults. Acquiring sputum samples from children is difficult and obtaining samples via bronchoscopy in children proves challenging due to the need for anesthesia and specialized procedural expertise; therefore nasopharyngeal (NP) swabs are often used as surrogates when investigating the pediatric airway microbiota. In adults, the airway microbiota differs significantly between NP and BALF samples however, minimal data exist in children.

Peanut Allergy: An Epidemiologic Analysis of a Large Database

Objective To confirm new observations on peanut allergy and answer current concerns that families and healthcare providers have about peanut allergy. Study design Children who presented with a story of peanut allergy or peanut sensitization were asked to participate in a registry, which allowed an analysis focused on questions that a food allergy support group had about children with peanut allergy or sensitization. Results A total of 1070 children were entered into the registry over 5 years. Two‐thirds had a reaction to peanut. Children with peanut allergy were predominantly male (63%), white (78%), and with private health insurance (80%). Most reactions involved the skin (55%) and anaphylaxis occurred in 35%. The median age of a reaction was 1 year old. Atopic dermatitis was noted in 60% and asthma in 41%. Additional food allergy was noted in 58%. When second exposures occurred 28% had a more severe reaction. Skin test size did not differentiate the type of a reaction and children with anaphylaxis had slightly higher specific IgE levels. Severe reactions with inadvertent exposure in children who were peanut sensitized was rare (<1%). Conclusions The strategies for peanut allergy prevention and treatment have evolved. The data obtained in this large registry can answer many questions that families and healthcare providers have during this transition.

Serum sickness-like reaction in a pediatric patient using omalizumab for chronic spontaneous urticaria

Omalizumab has been approved for chronic idiopathic urticaria (CIU)/chronic spontaneous urticaria (CSU) in children 12 years and older. Two treatment doses of omalizumab are available: 150 mg or 300 mg every 4 weeks. While 150 mg has been shown to be effective, most patients with CIU/CSU require 300 mg every 4 weeks to achieve symptom improvement. 1,2 . Although the cost of anti-IgE treatment can be high, there are reports of successful remission in CIU/CSU for difficult-to-treat cases, with 70.4% of patients treated with omalizumab reporting resolution of symptoms (versus 4.5% of placebo-treated patients)2,3 . This article is protected by copyright. All rights reserved.

ORAL FOOD CHALLENGE FAILURES AMONG FOODS RESTRICTED DUE TO ATOPIC DERMATITIS

BACKGROUND Recent studies have suggested that removing foods from the diet to manage atopic dermatitis (AD), based on positive allergy test results, may lead to immediate allergic reactions on reintroduction of that food. OBJECTIVE To examine the frequency of oral food challenge (OFC) failures among foods removed from the diet as suspected AD triggers, focusing on the 5 major food allergens in the United States. METHODS OFCs to egg, milk, peanut, soy, and wheat, performed from 2008 to 2014, at a childrens hospitals allergy clinics, were reviewed. OFCs were offered based on history and laboratory values. Reasons for food avoidance were classified as food allergy (IgE-mediated reaction occurring within 2 hours); sensitization only (lack of introduction because of positive test results); and removal because of test results during AD evaluation. RESULTS There were 442 OFCs performed, with 89 failures (20.1%). Reasons for OFCs included a history of food allergy (320 of 442 [72.4%]), food sensitization without any introduction (77 of 442 [17.4%]), and AD (45 of 442 [10.2%]). OFC failures among those who had food allergy (70 of 320 [21.9%]), sensitization only (13 of 77 [16.9%]), and suspected AD trigger (6 of 45 [13.3%]) did not significantly differ (P = .63). Wheat was more likely to be avoided than the other 4 foods for AD concerns (P < .001). CONCLUSION The frequency of OFC failure among those who removed foods suspected as AD triggers was 13.3%, indicating a loss of tolerance. Restriction of foods to manage AD must be done with caution and close monitoring.