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.