This synopsis book reports advances and key observations that will impact the care of children with allergic and immunologic diseases now and in the near future. Reviewers for the synopsis book selected many articles that have clinical “pearls” and provide insights that are applicable for daily practice, as well as ones that challenge our previous notions and provide data that may lead to new approaches for diagnosis and treatment.
Data about preventing allergies through dietary means continue to challenge our past dogma. In one large (>50 000 children) study, prolonged exclusive breastfeeding did not reduce the risk of eczema, and in another (almost 7000 children) study early introduction of allergenic foods was not associated with increased risks of wheeze or eczema. Several other studies identify various hereditary risk factors that may be more easily monitored for prediction and targeted therapy or prevention of atopic disease in the future.
A national Internet-based study of food allergy estimated that 8% of children are affected, with apparent disparities in diagnosis by racial and economic factors. The apparent increase in food allergy pressures the need for therapies, and additional studies reviewed here show that for some children with milk allergy, foods with extensively heated milk (eg, muffins) may be tolerated and ingesting them may speed tolerance to whole milk (but care is needed because some children will have anaphylaxis to the baked foods and cannot add them to their diet). Data are accumulating on oral immunotherapy, the gradual oral dosing of the causal food, but more studies on efficacy and risks are needed. Emerging diagnostic tests for food allergy may improve the ability to ascertain which children have true allergy, and our Section on Allergy and Immunology developed a clinical report on this and related allergy diagnostics topics.1 Another food allergy–related disorder is eosinophilic esophagitis. Studies reviewed here point out the most typical causal foods and the unfortunate chronic nature of the disease. A comprehensive review of this disorder was also published this year.2
Several important observations were reported for drug allergy, anaphylaxis, and skin disease. Most children with penicillin allergy tolerate cephalosporins, although referral to an allergist is often warranted (and there are now reagents available for improved testing to penicillin). Several studies on anaphylaxis underscore that teenagers are prone to underuse self-injectable epinephrine for anaphylaxis. This is clearly an area in which additional advice, education, and encouragement by pediatricians and allergists may help to save a life. In the area of allergic skin disease, a large study of children with chronic urticaria showed that autoimmune responses are the primary trigger, and prognosis is good with resolution in half of the children within 5 years.
Regarding asthma, several studies explore a relationship to obesity, indicating that it is current rather than earlier obesity that is a risk, and obesity is associated with specific immune alterations. Additional insights in asthma include that early mold exposure may be a risk factor, that sleep-disordered breathing may contribute to asthma severity apart from obesity, that parents often misperceive their child’s asthma control, that inadequate use of controller medications is a common problem, and that there appears to be an overuse of antibiotics during asthma exacerbations. Regarding medical therapies, a landmark study compared the efficacy of daily low-dose inhaled glucocorticoids versus intermittent high-dose inhaled glucocorticoids in children at risk for asthma exacerbations. The study found that a daily low-dose regimen of budesonide was not superior to an intermittent high-dose regimen in reducing asthma exacerbations, and the daily administration led to greater exposure to the drug at 1 year. The study focused on a specific clinical scenario, so be sure to read more! Given parental fear of steroids, it was helpful to see a reassuring study that 1 year of chronic use of the inhaled corticosteroid flunisolide HFA (85 μg/puff) for the treatment of mild persistent asthma did not suppress growth or bone maturation at the highest approved dose. A meta-analysis gave mixed reassurance regarding the safety of long-acting β2-adrenergic receptor antagonists. The study concluded that, although there was a higher incidence of asthma events associated with long-acting β2-adrenergic receptor antagonists use, this increased risk was not observed in a subgroup also prescribed regular inhaled corticosteroids (however, the small number of pediatric patients in this subgroup requires more study to draw strong conclusions). Although use in children needs more study, a large analysis of the potential for malignancy related to use of omalizumab failed to show a relationship. A cornerstone of respiratory allergy therapy is immunotherapy. A large meta-analysis showed that pediatric patients with allergy benefitted from treatment with subcutaneous immunotherapy by using house dust mite, Alternaria, and grass pollen. The treatment has a good safety profile, but additional approaches reviewed herein include the sublingual route.
Synopsis book reviewers selected a relatively large number of articles along 2 thematic paths related to allergy and immunology: the microbiome and vitamin D. Regarding the microbiome, insights included that dietary factors may alter intestinal cellular functions and that the types and diversity of gut bacteria affect immune response (which may alter the balance toward adverse inflammatory responses and allergy if the diversity is low, as shown in an epidemiological study). Studies reviewed here focus on the molecular mechanisms at play, suggesting potential targets for therapy given our possible current societal state of immune dysregulation caused by improved hygiene.
Vitamin D plays a role in immune regulation, and studies reviewed here suggest that deficiency is related to an increased risk for and severity of asthma and increased glucocorticoid requirements, and that the relationship is particularly important in children in comparison with adults. Vitamin D deficiency is also associated with food sensitization in individuals with specific genotypes, suggesting an interaction between these features and food sensitization. The role of sunlight and supplementation for treatment requires more study.
In the field of primary immunodeficiency and infectious diseases, studies reviewed here indicate that the easy screening methods (10 Warning Signs of Primary Immunodeficiency) that have been promulgated for many years may have low sensitivity and specificity, and so pediatricians truly need to maintain a high index of suspicion. Increasing use of neonatal screening with the T-cell receptor excision circle assay may help to identify infants at risk of significant immunodeficiencies and allow them to be “rescued” before infections occur. Those testing at risk require a comprehensive evaluation by an allergist-immunologist. Additional studies reviewed here indicate the efficacy of various regimens to treat HIV and also an important “negative” study showing that treatment with intravenous immune globulin does not have efficacy in treating infants with sepsis.
On behalf of myself and our reviewers, we hope that this supplement stimulates and informs, giving you practical information to improve the care of children with allergic and immunologic diseases now, and an exciting peek out of a window toward understanding therapies on the horizon. For additional information about our Section, please visit: http://www.aap.org/sections/allergy/.
This supplement was supported by an unrestricted educational grant from Merck. However, Merck had no role in the selection of the articles reviewed.
- Copyright © 2012 by the American Academy of Pediatrics