Development of food allergies in patients with gastroesophageal reflux disease treated with gastric acid suppressive medications.

BACKGROUND: The prevalence of food allergy has steadily increased, especially in children. Reflux disease, a very common problem in children, is often treated with gastric acid suppressive (GAS) medications which may alter the processing of food allergens, thereby affecting oral mucosal tolerance. OBJECTIVE: The purpose of this study was to determine if use of GAS medications is associated with the occurrence of food allergies in children. METHODS: Using a large national commercial insurance database, we identified 4724 children aged 0-18 yrs who were diagnosed with Gastroesophageal Reflux Disease (GERD) and treated with GAS medications between January 1, 2008 and September 30, 2009. We then matched 4724 children with GERD not treated with GAS medications and 4724 children without GERD and not treated with GAS medications, at a 1:1 ratio, on age, gender and number of atopic risk factors. Patients were followed for 12 months. RESULTS: In comparison to the referent (children without GERD who received no GAS medications), children with GERD who were treated with GAS were more likely to be diagnosed with a food allergy (Hazard ratio (HR): 3.67, 95% CI 2.15-6.27), as were children with GERD diagnosis but who were not treated with GAS medications (HR: 2.15, 95% CI: 1.21-3.81). A direct comparison of the two GERD cohorts showed that children with GERD who were treated with GAS had a greater risk of food allergy than those with GERD who were untreated (HR, 1.68, 95%CI, 1.15-2.46). CONCLUSION: Treatment with GAS medications is associated with the occurrence of food allergy, an effect not apparently related to a diagnosis of GERD alone.

Estrogen effects in allergy and asthma.

PURPOSE OF REVIEW: Asthma prevalence and severity are greater in women than in men, and mounting evidence suggests this is in part related to female steroid sex hormones. Of these, estrogen has been the subject of much study. This review highlights recent research exploring the effects of estrogen in allergic disease. RECENT FINDINGS: Estrogen receptors are found on numerous immunoregulatory cells and estrogen's actions skew immune responses toward allergy. It may act directly to create deleterious effects in asthma, or indirectly via modulation of various pathways including secretory leukoprotease inhibitor, transient receptor potential vanilloid type 1 ion channel and nitric oxide production to exert effects on lung mechanics and inflammation. Not only do endogenous estrogens appear to play a role, but environmental estrogens have also been implicated. Environmental estrogens (xenoestrogens) including bisphenol A and phthalates enhance allergic sensitization in animal models and may enhance development of atopic disorders like asthma in humans. SUMMARY: Estrogen's role in allergic disease remains complex. As allergic diseases continue to increase in prevalence and affect women disproportionately, gaining a fuller understanding of its effects in these disorders will be essential. Of particular importance may be effects of xenoestrogens on allergic disease.

Severe serum sickness after H1N1 influenza vaccination.

In this study, the case of a 48-year-old man with severe serum sickness reaction in response to H1N1 influenza immunization is reported. He presented with renal failure and several of the classic signs reported in early descriptions of serum sickness by Clemens von Pirquet and Bela Schick including lymphadenopathy, urticarial skin eruption and facial edema. Serum immunologic studies and tissue histology/immunohistochemistry assisted in firmly establishing the diagnosis in this case. With appropriate therapy, the patient's rash, edema and lymphadenopathy resolved and normal renal function returned. This first reported case of severe serum sickness to H1N1 vaccine is particularly important in light of the Centers for Disease Control and Prevention's recommendation for universal vaccination against influenza, including H1N1, in patients 6 months and older. With increasing numbers of patients receiving this vaccine, even rare adverse reactions may be experienced by numerous individuals. It is imperative that clinicians remain vigilant about possible reactions and quickly institute appropriate therapy.

A structural basis for food allergy: the role of cross-reactivity.

PURPOSE OF REVIEW: Immunologic cross-reactivity, which is important in many aspects of host defense and immune-mediated diseases, is a prominent feature of allergic disorders. The goal of this article is to define allergenic cross-reactivity and its role in food allergy, review current understanding of mechanisms of cross-reactivity, and consider how advances in our ability to predict cross-reactivity can impact diagnosis and treatment of food allergy. RECENT FINDINGS: Recent evidence suggests that specific T cells, in addition to IgE, developed in response to inhaled allergens can cross-react with related food allergens, leading to distinct clinical reactions. Several new cross-reactivities have been identified, including food-food, pollen-food, and latex-venom associations. Debate continues regarding prediction of allergenicity based on protein structure, and clinical relevance of in-vitro testing. Cross-reactivity is also being used to develop specific immunotherapy for treatment of food allergy. SUMMARY: A thorough understanding of immunologic cross-reactivity is essential to advancing our knowledge about food allergy. This knowledge will help elucidate the pathogenesis of the disorder and prevent exposures to allergenic, genetically engineered foods. New insight will allow for better utilization of current diagnostic tools and the development of more accurate tests and therapies for food allergy.