Nasal histamine provocation of tenants in a sick-building residential area.

Health problems associated with the indoor climate have aroused an increasing scientific interest, and the term "sick-building syndrome" (SBS), which describes the most frequent symptoms in this context, has been coined. However, it has been difficult to demonstrate objectively any pathophysiological changes in the subjects affected. Thirty-three healthy and nonatopic persons were randomly selected on the basis of answers in a postal questionnaire dealing with discomfort or health symptoms experienced in their home environment. Twenty-three lived in a residential area with indoor climate problems (SBS area) and 10 lived in an area without climate problems (non-SBS area). Twelve persons from the SBS area reported nasal symptoms, which they ascribed to their home environment. The remaining 11 persons from the same area, as well as the 10 subjects from the non-SBS area, had no nasal distress. They were examined with rhinostereometry during histamine provocation. Hyperreactivity, defined as mucosal swelling exceeding 0.4 mm at 5 and 10 minutes after provocation with 0.14 ml of 2 mg/ml histamine chloride, was frequent in the symptomatic SBS group as well as in the asymptomatic SBS group. The analysis of the increment of mucosal swelling for the whole range of histamine chloride concentrations (0.1 mg/ml to 16 mg/ml) showed significantly different growth curves for the three groups in the residential areas and an external reference group, (p < 0.0001). Subjects living in the SBS area were prone to nasal hyperreactivity, whether they reported symptoms from the upper airways or not. The results support the hypothesis that living in an SBS area increases the risk of developing nonspecific nasal hyperreactivity.