title: A double blind, placebo controlled trial of inert cellulose powder for the relief of symptoms of hay fever in adults.
abstract: OBJECTIVE
  An inert cellulose powder has been on sale in the UK since 1994 as a remedy for hay fever but no scientific trials have been conducted previously. It is applied to the inside of the nose where it forms a gelatinous coating. The principal aim was to determine if there is a significant difference in the amount and type of rescue medication required for adult hay fever sufferers to control their symptoms while using either the inert cellulose powder or a placebo. The second objective was to see whether the cellulose powder resulted in an improvement in symptom control.
  
  
  METHODS
  A double blind, placebo controlled study was conducted of 97 adult hay fever sufferers, over the grass pollen season of 2004. Participants (selectively recruited to be living within the catchment area of a 50-km radius from Worcester, UK) were assigned randomly to two groups (A, Active and B, Placebo) matched by age by decades and gender. Of those completing the trial, group A had 19 males and 28 females and group B had 21 males and 29 females. There were no significant differences between the groups in age distributions, severity of symptoms over the last 2 years or in medication taken. They completed daily symptom diary score cards and were allowed to take any medications they wished in addition to the inert cellulose powder or placebo because medication use was taken as an outcome measure. Results were analysed in relation to pollen counts.
  
  
  RESULTS
  Significant differences were found in the amounts of rescue medication taken by the active and placebo groups (p < 0.05). More people in the placebo group took rescue treatments than those in the active group. No significant differences were found (p < 0.01) between the active and placebo groups in Likert scores for any of the rhinitis nasal symptoms or in the total Likert symptom daily scores. No adverse events were reported during the study.
  
  
  CONCLUSIONS
  The amount of rescue medication taken by the placebo group was significantly more than that taken by the active group both overall, considering all types of medication, and also in the individual cases of antihistamines, nasal sprays and eye drops. These results provide evidence that the inert cellulose powder reduces the need to take rescue medication for the symptoms of hay fever.
authors.affiliation: National Pollen and Aerobiology Research Unit, Institute of Health, University of Worcester, Worcester, WR2 6AJ, UK. j.emberlin@worc.ac.uk
authors.forename: J C
authors.initials: JC
authors.lastname: Emberlin
authors.forename: R A
authors.initials: RA
authors.lastname: Lewis
mesh_terms: D000293:Adolescent; D000328:Adult; D002482:Cellulose / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D006109:Poaceae / Q000009:adverse effects; D011208:Powders; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy*; D006113:United Kingdom
chemical_list: D010919:Placebos; D011208:Powders; D002482:Cellulose