Effect of air cleaners on mold count in the air and on the symptoms of perennial rhinitis

Seventy-five children (ages 4 to 14 years) with perennial rhinitis caused by mold allergy (36 had asthma) were enrolled in an air-cleaner study for 2 years. Symptom scores prior to the study were compared with scores 1 and 2 years after placement of air-cleaners in the bedrooms. Forty-two homes were surveyed for mold count in the air in summer and winter, and the results compared with symptom changes. Improvements were found in quality of sleep (96 vs. 99%), sneezing (80 vs. 90%), scratchy throat (75 vs. 80%), night cough (75 vs. 83%), better mood in the morning (65 vs. 80%), postnasal drip (70 vs. 77%), nasal congestion (70 vs. 72%), night wheezing (70 vs. 83%), and sinus infection (50 vs. 55%). Parents reported a decrease in the use of both over-the-counter (76 vs. 80%) and prescription (43 vs. 48%) drugs. When the weekly symptom score sheets were compared, symptom recurrence rates were found to be clustered in the winter. These symptoms were cough (35%), nasal congestion (35%), sinus infection (32%), and postnasal drip (20%). The average mold counts (expressed as colony-forming-units per cubic meter of air) in the filtered bedrooms, in the unfiltered bedrooms, and outdoors were 310, 425, and 927 in the summer, and 689, 762, and 1213 in the winter, respectively. The higher mold count in the winter may explain the increase in symptoms during that season. We observed a significant improvement in respiratory symptoms for 2 years following the installation of air-cleaners in the bedrooms of 75 children with perennial rhinitis due to mold allergy.