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Here I present the latest published articles within the field of SHR

I
How common is SHR in a population?
6% of the adult Swedish population could be diagnosed with SHR. This estimation is based on the combination of a positive capsaicin inhalation cough test and high scoring for a questionnaire measuring the impact of scenting chemicals on daily lift activities.

Titel: Relationship between self-reported odor intolerance and sensitivity to inhaled capsaicin: proposed definition of airway sensory hyperreactivity and estimation of its prevalence

Authors: Johansson A, Millqvist E, Nordin S, Bende M

Journal: Chest. 2006 Jun;129(6):1623-8

Abstract: STUDY OBJECTIVES: The aim of this study was to investigate the relationship between the behavioral consequences of self-reported odor sensitivity with the chemical sensitivity scale for sensory hyperreactivity (CSS-SHR) and cough sensitivity to inhaled capsaicin. We also wanted to estimate the prevalence of airway sensory hyperreactivity (SHR), which was defined as a positive CSS-SHR score in combination with a positive capsaicin inhalation test result. DESIGN: A general population-based study with randomly selected individuals after stratification for age and gender. SETTING: Skovde Central Hospital , Departments of Lung Medicine and Otorhinolaryngology , Sweden . PARTICIPANTS: A total of 693 randomly selected individuals from a population-based study in which 595 persons (86%) responded to the CSS-SHR questionnaire. INTERVENTIONS: The individuals were divided into four groups with different odor sensitivity according to their CSS-SHR score. Of these, 137 individuals were randomly recruited for the capsaicin inhalation test. Capsaicin inhalation was performed with concentrations of 0.4 and 2.0 mumol/L in a randomized order. The number of coughs were registered and counted for 10 min from the start of each inhalation. MEASUREMENTS AND RESULTS: Of the 137 individuals who were recruited for the capsaicin inhalation test, 103 (75%) participated. Sixteen individuals had increased cough sensitivity and fulfilled the criteria for a positive capsaicin inhalation test result. Of the individuals with a positive capsaicin inhalation test result, > 80% also had a positive CSS-SHR score. Only 5% of the individuals with a negative CSS-SHR score had a positive capsaicin inhalation test result. The order of inhaled capsaicin concentration was found to influence the results. The prevalence of SHR with the definition given above was estimated to be 6.3% in this general population. CONCLUSIONS: A high CSS-SHR score was found to be directly related to the sensitivity for inhaled capsaicin, which made it possible to relate subjective data to objective findings.

PMID: 16778284 [PubMed - indexed for MEDLINE]

The full text is available at: http://www.chestjournal.org/

II
The connection between the upper and lower airways in SHR
In SHR it is common with symptoms from both the upper and the lower airways. This is a review article discussing the role of the upper airways in patients with chronic cough due to SHR.

Titel: Role of the upper airways in patients with chronic cough

Authors: Millqvist E, Bende M

Journal: Curr Opin Allergy Clin Immunol. 2006 Feb;6(1):7-11

Abstract: PURPOSE OF THE REVIEW: Chronic cough can be caused by a number of factors, including infections, rhinosinusitis, asthma and environmental stimuli. This paper reviews recent findings and opinions regarding the role played by the upper airways in chronic cough. RECENT FINDINGS: Chronic cough has a significant impact on quality of life, which is more pronounced in women. In Western countries, the reported occurrence of rhinosinusitis in patient groups with chronic cough ranges from 8% to 81%. Allergic rhinitis is a risk factor for later development of asthma. In children, bronchiectasis is combined with upper airway abnormalities in the majority of cases. Increased expression of the capsaicin receptor subtype named 'transient receptor potential vanilloid-1', which correlates with capsaicin cough response, has been identified in patients with chronic cough. Patients with airway chemical sensitivity and chronic cough as one symptom have augmented capsaicin cough sensitivity that is related to changed levels of nerve growth factor in nasal lavage. SUMMARY: Involvement of the upper airways in chronic cough has been confirmed in several studies. However, there are considerable differences between different health centres in the occurrence of rhinosinusitis as a cause of chronic cough. In patients with chronic cough of various causes, a neurochemical alteration in both the upper and the lower airways appears to have taken place, followed by increased cough sensitivity.

PMID: 16505605 [PubMed - indexed for MEDLINE]

The full text is available at: http://www.currentopinion.com