O. Löwhagen

Sensory hyperreactivity--a possible mechanism underlying cough and asthma-like symptoms.

Background Investigations of patients referred for suspected asthma have revealed a little‐known group with symptoms suggesting hyperreactive airways in whom provocation with methacholine does not lead to bronchial obstruction. The underlying mechanisms are not known, and no objective diagnostic method has been available.

The Chemical Sensitivity Scale: Psychometric properties and comparison with the noise sensitivity scale

Abstract A questionnaire-based tool for quantifying self-reported affective reactions to and behavioral disruptions by odorous/pungent substances, called the Chemical Sensitivity Scale (CSS), analogous to the Noise Sensitivity Scale (NSS), was evaluated regarding psychometric properties. Twenty-six members from the Swedish Asthma and Allergy Association and 124 control participants responded to the CSS, the NSS, and to additional questions for evaluation of the validity of the CSS and NSS. The results showed that the CSS generates approximately normal distributions, has good test–retest reliability ( r xy =0.87), good internal consistency ( r α =0.88), and satisfying predictive and concurrent validity. These metric properties of the CSS and NSS were in general very similar. The content validity of the CSS is discussed. Two major dimensions of the CSS appear to represent sensory/somatic and neurasthenic symptoms, respectively. The analogy of the CSS to the NSS implies that use of both scales in combination may enhance understanding for the issue of general environmental sensitivity versus specific sensitivity to chemicals. Correlation coefficients between CSS and NSS scores for the asthma and allergy members ( r xy =0.40) and controls ( r xy =0.42) imply a moderate correspondence between chemical and noise sensitivity.

Quality of Life and Capsaicin Sensitivity in Patients with Airway Symptoms Induced by Chemicals and Scents: A Longitudinal Study

Objective It is common in asthma and allergy clinics to see patients presenting with upper and lower airway symptoms that are induced by chemicals and scents and not explained by allergic or asthmatic reactions. Previous studies have shown that these patients often have increased cough sensitivity to inhaled capsaicin; such sensitivity is known to reflect the airway sensory reactivity. The aim of this study was to evaluate the duration of symptoms induced by chemicals and scents and to measure health-related quality of life (HRQL) in patients with chemically induced airway symptoms. We also wished to determine and compare repeatability of the cough response to capsaicin inhalation, and to evaluate the patients’ airway sensory reactivity in a long-term perspective. Participants Seventeen patients with a history of at least 12 months of airway symptoms induced by chemicals and scents were followed over 5 years with repeated questionnaires, measurements of HRQL, and capsaicin inhalation tests. Results The symptoms persisted and did not change significantly over time, and the patients had a reduced HRQL that did not change during the 5-year period. The capsaicin sensitivity was increased at the start of the study, the cough sensitivity was long-lasting, and the repeatability of the capsaicin inhalation test was considered to be good in a long-term perspective. Conclusions Upper and lower airway symptoms induced by chemicals and scents represent an entity of chronic diseases, different from asthma or chronic obstructive pulmonary disease, with persistent symptoms, a reduced HRQL, and unchanged sensory hyperreactivity.

Provocations with perfume in the eyes induce airway symptoms in patients with sensory hyperreactivity

Background: In earlier studies, we have shown that patients with a history of sensory hyperreactivity develop asthma‐like symptoms when exposed to strong scents, even if they cannot smell any scent.

Haplotypes of the interleukin-4 receptor alpha chain gene associate with susceptibility to and severity of atopic asthma.

Background Development of asthma is likely to depend on a complex interaction between environmental and genetic factors. Several groups have suggested the gene of the IL‐4 receptor α chain (IL4R) as a candidate gene for the development of asthma, although association with single polymorphisms has shown contradicting results.

Nasal eosinophilia and IL-5 mRNA expression in seasonal allergic rhinitis induced by natural allergen exposure : effect of topical corticosteroids

BACKGROUND Nasal allergen provocation in patients with allergic rhinitis leads to expression of the proeosinophilic cytokines IL-5 and GM-CSF and tissue eosinophilia. OBJECTIVE We sought to examine the effect of natural seasonal allergen exposure on IL-5 and GM-CSF mRNA expression and nasal eosinophilia and to evaluate the effects of topical corticosteroid therapy on these responses. METHODS Nasal biopsy specimens were collected from 46 grass pollen-sensitive patients with seasonal rhinitis before the grass pollen season. A second biopsy specimen was collected during the pollen season, by which time patients had received 6 weeks treatment with either fluticasone propionate (200 micro(g) twice daily) or placebo nasal spray. RESULTS Fluticasone treatment was clinically effective (P <.005). Patients receiving placebo, but not fluticasone, showed increased numbers of epithelial and submucosal EG2+ eosinophils (P <.005) and IL-5 and GM-CSF mRNA-expressing cells (P <.0001) during the pollen season. Colocalization experiments showed that greater than 80% of IL-5 mRNA-expressing cells were submucosal CD3+ T cells in both groups. The numbers of submucosal CD3+ T cells did not increase during the pollen season or decrease with fluticasone treatment. Fluticasone also inhibited IL-5 secretion by grass pollen-stimulated peripheral blood T cells from patients with seasonal rhinitis (n = 5, inhibitory concentration of 50% = 10(-9) to 10(-10) mol/L). CONCLUSIONS These results suggest that topical corticosteroids may reduce eosinophilia in seasonal rhinitis by inhibiting T cell IL-5 production.

Recruitment of CD1a+ Langerhans cells to the nasal mucosa in seasonal allergic rhinitis and effects of topical corticosteroid therapy.

Background: Local antigen presentation may be necessary for both primary and recall T‐cell responses to grass pollen in hay fever patients. We examined the effect of seasonal allergen exposure on nasal mucosal antigen‐presenting cell (APC) populations and the effects of topical corticosteroid therapy.

Late asthmatic reaction decreased after pretreatment with salbutamol and formoterol, a new long-acting β2-agonist

The inhibitory effect of salbutamol and formoterol, a new long-acting beta 2-agonist for inhalation, on the late asthmatic reaction (LAR), was studied in 12 patients with allergic asthma. After a single-blind, placebo-treatment control, equipotent bronchodilating doses of inhaled salbutamol (500 micrograms) and formoterol (30 micrograms) were administered 30 minutes before bronchial allergen challenge in a double-blind randomized design. The early asthmatic reaction was completely inhibited by both drugs (p less than 0.01) but not by placebo. The LAR was also significantly inhibited by both drugs (p less than 0.01); formoterol was only slightly, but significantly, more effective than salbutamol (p = 0.04). In contrast to some earlier studies, the present study indicates an inhibitory effect of beta 2-agonists on the LAR.

Quality of life and capsaicin sensitivity in patients with sensory airway hyperreactivity.

Background: A group of patients with asthma‐like symptoms and sensitivity to chemical irritants has shown an increased cough sensitivity to inhaled capsaicin compared to patients with asthma and to healthy controls. The condition is called sensory hyperreactivity (SHR), and the patients often feel that they are socially handicapped because of the risk of exposure to chemical irritantsin daily life.

Capsaicin cough sensitivity in allergic asthmatic patients increases during the birch pollen season.

BACKGROUND A change in neural responsiveness may occur as the result of allergic inflammation in the lower airways as well as in the upper airways. In the lower airways, capsaicin cough sensitivity is known to reflect sensory neural reactivity. OBJECTIVE The aim of this study was to establish whether allergic inflammation changes airway neural sensory reactivity during prolonged allergen exposure. METHODS Ten nonsmoking patients with birch pollen-allergic asthma performed a capsaicin inhalation challenge twice, once in the off-pollen season and once during the pollen season. The number of coughs and symptoms induced by capsaicin were recorded and compared with those of healthy control subjects. RESULTS The response to capsaicin, expressed as number of coughs, increased in a dose-dependent manner during both tests. Before the season, the response was similar to that of healthy control subjects, but during the pollen season, the reactivity was significantly increased. Variations in forced expiratory volume in 1 second were not significant before and after each challenge, and values did not change during the pollen season as compared with the winter season. CONCLUSIONS Sensory reactivity in allergic asthmatic patients may be increased during prolonged allergen exposure as during the pollen season. This finding suggests that allergic inflammation in the lower and/or upper airways may trigger neurogenic mechanisms of significant clinical importance.