Allergic rhinitis is a symptomatic disorder of the nose induced after allergen exposure by an IgE-mediated inflammation of the membranes lining the nose. It is a global health problem that causes major illness and disability worldwide. Over 600 million patients from all countries, all ethnic groups and of all ages suffer from allergic rhinitis. It affects social life, sleep, school and work and its economic impact is substantial. Risk factors for allergic rhinitis are well identified. Indoor and outdoor allergens as well as occupational agents cause rhinitis and other allergic diseases. The role of indoor and outdoor pollution is probably very important, but has yet to be fully understood both for the occurrence of the disease and its manifestations.

In 1999, during the Allergic Rhinitis and its Impact on Asthma (ARIA) WHO workshop, the expert panel proposed a new classification for allergic rhinitis which was subdivided into 'intermittent' or 'persistent' disease.

This classification is now validated. The diagnosis of allergic rhinitis is often quite easy, but in some cases it may cause problems and many patients are still under-diagnosed, often because they do not perceive the symptoms of rhinitis as a disease impairing their social life, school and work.

The management of allergic rhinitis is well established and the ARIA expert panel based its recommendations on evidence using an extensive review of the literature available up to December 1999. The statements of evidence for the development of these guidelines followed WHO rules and were based on those of Shekelle et al. A large number of papers have been published since 2000 and are extensively reviewed in the 2008 Update using the same evidence-based system. Recommendations for the management of allergic rhinitis are similar in both the ARIA workshop report and the 2008 Update. In the future, the GRADE approach will be used, but is not yet available.

Another important aspect of the ARIA guidelines was to consider co-morbidities. Both allergic rhinitis and asthma are systemic inflammatory conditions and often co-exist in the same patients. In the 2008 Update, these links have been confirmed.

The ARIA document is not intended to be a standard-of-care document for individual countries. It is provided as a basis for physicians, health care professionals and organizations involved in the treatment of allergic rhinitis and asthma in various countries to facilitate the development of relevant local standard-of-care documents for patients.

/pdf/allergic-rhinitis-and-its-impact-on-asthma-aria-2008-update-13eqfzaw4u.pdf

Allergic rhinitis and its impact on asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen)

Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma

Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial

Background: Measurement of fractional nitric oxide (NO) concentration in exhaled breath (FeNO) is a quantitative, noninvasive, simple, and safe method of measuring airway inflammation that provides a complementary tool to other ways of assessing airways disease, including asthma. While FeNO measurement has been standardized, there is currently no reference guideline for practicing health care providers to guide them in the appropriate use and interpretation of FeNO in clinical practice.Purpose: To develop evidence-based guidelines for the interpretation of FeNO measurements that incorporate evidence that has accumulated over the past decade.Methods: We created a multidisciplinary committee with expertise in the clinical care, clinical science, or basic science of airway disease and/or NO. The committee identified important clinical questions, synthesized the evidence, and formulated recommendations. Recommendations were developed using pragmatic systematic reviews of the literature and the GRADE approach....

/pdf/an-official-ats-clinical-practice-guideline-interpretation-1iahut6ven.pdf

An official ATS clinical practice guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications.

The increase of allergic diseases in the industrialized world has often been explained by a decline in infections during childhood. The immunological explanation has been put into the context of the functional T cell subsets known as T helper 1 (TH1) and T helper 2 (TH2) that display polarized cytokine profiles. It has been argued that bacterial and viral infections during early life direct the maturing immune system toward TH1, which counterbalance proallergic responses of TH2 cells. Thus, a reduction in the overall microbial burden will result in weak TH1 imprinting and unrestrained TH2 responses that allow an increase in allergy. This notion is contradicted by observations that the prevalence of TH1-autoimmune diseases is also increasing and that TH2-skewed parasitic worm (helminth) infections are not associated with allergy. More recently, elevations of anti-inflammatory cytokines, such as interleukin-10, that occur during long-term helminth infections have been shown to be inversely correlated with allergy. The induction of a robust anti-inflammatory regulatory network by persistent immune challenge offers a unifying explanation for the observed inverse association of many infections with allergic disorders.

https://science.sciencemag.org/content/sci/296/5567/490.full.pdf

Allergy, Parasites, and the Hygiene Hypothesis

https://ftp.cdc.gov/pub/documents/oel/06. dotson/references/platts-mills_2001.pdf

Sensitisation, asthma, and a modified Th2 response in children exposed to cat allergen: a population-based cross-sectional study.

Exhaled breath condensate (EBC) pH is low in several lung diseases and it normalises with therapy. The current study examined factors relevant to EBC pH monitoring. Intraday and intraweek variability were studied in 76 subjects. The pH of EBC collected orally and from isolated lower airways was compared in an additional 32 subjects. Effects of ventilatory pattern (hyperventilation/hypoventilation), airway obstruction after methacholine, temperature (-44 to +13 degrees C) and duration of collection (2-7 min), and duration of sample storage (up to 2 yrs) were examined. All samples were collected with a disposable condensing device, and de-aerated with argon until pH measurement stabilised. Mean EBC pH (n=76 subjects, total samples=741) was 7.7+/-0.49 (mean+/-SD). Mean intraweek and intraday coefficients of variation were 4.5% and 3.5%. Control of EBC pH appears to be at the level of the lower airway. Temperature of collection, duration of collection and storage, acute airway obstruction, subject age, saliva pH, and profound hyperventilation and hypoventilation had no effect on EBC pH. The current authors conclude that in health, exhaled breath condensate pH is slightly alkaline, held in a narrow range, and is controlled by lower airway source fluid. Measurement of exhaled breath condensate pH is a simple, robust, reproducible and relevant marker of disease.

https://erj.ersjournals.com/content/erj/22/6/889.full.pdf

Exhaled breath condensate pH is a robust and reproducible assay of airway acidity

Fluid condensed from the breath of patients with acute asthma is acidic. Several features of asthma pathophysiology can be initiated by exposure of the airway to acid. In renal tubular epithelium, glutaminase produces ammonia to buffer urinary acid excretion. We hypothesized that human airway epithelium could also express glutaminase. Here, we demonstrate that human airway epithelial cells in vitro have biochemical evidence for glutaminase activity and express mRNA for two glutaminase isoforms (KGA and GAC). Glutaminase activity increased in response to acidic stress (media pH 5.8) and was associated with both increased culture medium pH and improved cell survival. In contrast, activity was inhibited by interferon-gamma and tumor necrosis factor-alpha. Glutaminase protein was expressed in the human airway in vivo. Further, ammonia levels in the breath condensate of subjects with acute asthma were low (30 microM [range: 0-233], n = 18, age 23 +/- 2.5 yr) compared with control subjects (327 microM [14-1,220], n = 24, age 24 +/- 2.4 yr, p < 0.001), and correlated with condensate pH (r = 0.58, p < 0.001). These data demonstrate that glutaminase is expressed and active in the human airway epithelium and may be relevant both to the regulation of airway pH and to the pathophysiology of acute asthmatic airway inflammation.

Expression and activity of pH-regulatory glutaminase in the human airway epithelium.

Avoidance of exposure to indoor allergens is an important element in the treatment of allergic disease. The results of several studies provide strong evidence in support of a role for allergen avoidance; however, strategies that optimize allergen reduction in houses have not been determined. Complex issues regarding the efficacy of physical and chemical measures that target house dust mite, pet, and cockroach allergens in the home are discussed. The greatest challenge is to educate allergic patients so that they can play an important role in controlling their own disease.

The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease

Iconographies supplémentaires de l'article : The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease

John W. Vaughan

Papers

Sensitisation, asthma, and a modified Th2 response in children exposed to cat allergen: a population-based cross-sectional study.

Exhaled breath condensate pH is a robust and reproducible assay of airway acidity

Expression and activity of pH-regulatory glutaminase in the human airway epithelium.

The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease

Iconographies supplémentaires de l'article : The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease