Nasal pathology and ultrastructure in patients with chronic airway inflammation (RADS and RUDS) following an irritant exposure.
BACKGROUND
Reactive airways dysfunction syndrome is a chronic asthma-like condition developing after an acute irritant exposure, and chronic inflammation has been seen on endobronchial biopsy. Reactive upper-airways dysfunction syndrome is chronic rhinitis developing in temporal association with a toxic inhalation exposure, but the pathophysiology is unknown.


OBJECTIVE
To study biopsies of the nasal mucosa in patients with reactive upper-airways dysfunction syndrome and in some cases reactive airways dysfunction syndrome developing in temporal association with a chlorine dioxide exposure, to see if a histologic basis for the persistent rhinitis and sensitivity to chemical irritants could be determined.


METHODS
Specimens were stained with hematoxylin-eosin and immunoperoxidase stains for substance P, vasointestinal peptide, and S-100 (nerve fibers), and fixed in glutaraldehyde for electron microscopy. Biopsies of three nonexposed subjects were performed for comparison. A pathologist blinded to clinical data interpreted the specimens.


RESULTS
Inflammation ratings of exposed individuals were higher than for the nonexposed individuals. The number of nerve fibers stained was greater for patients vs controls. Substance P and vasointestinal peptide staining was nonspecific. Electron microscopy showed desquamation of the epithelium and permeability of epithelial cell junctions.


CONCLUSIONS
This study suggests a mechanism by which ongoing low level exposures perpetuate airway inflammation after an inducing toxic inhalation. A possible overlap between reactive airways dysfunction syndrome, reactive upper-airway dysfunction syndrome and the multiple chemical sensitivity syndrome is suggested.
Meggs
W J
WJ
Department of Emergency Medicine, East Carolina University School of Medicine, Greenville, NC 27858, USA.
Elsheik
T
T
Metzger
W J
WJ
Albernaz
M
M
Bloch
R M
RM
D000328:Adult; D001485:Basement Membrane / Q000648:ultrastructure; D001706:Biopsy; D002713:Chlorine / Q000506:poisoning*; D017606:Chlorine Compounds; D003710:Demography; D004202:Disinfectants / Q000506:poisoning*; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008019:Life Style; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009297:Nasal Mucosa / Q000187:drug effects / Q000473:pathology*; D009412:Nerve Fibers / Q000473:pathology; D016273:Occupational Exposure / Q000009:adverse effects*; D010087:Oxides / Q000506:poisoning*; D012130:Respiratory Hypersensitivity / Q000139:chemically induced* / Q000473:pathology; D012220:Rhinitis / Q000139:chemically induced / Q000473:pathology; D019108:Tight Junctions / Q000648:ultrastructure
D017606:Chlorine Compounds; D004202:Disinfectants; D010087:Oxides; D002713:Chlorine; C025109:chlorine dioxide