THE EFFECT OF LOCAL HYPERTHERMIA ON ALLERGEN-INDUCED NASAL CONGESTIONAND MEDIATOR RELEASE

Background: Local hyperthermia reduces mast cell degranulation, the se verity of acute lung injury, and exercise-induced asthma and decreases symptoms of rhinitis. We have investigated the effect of local hypert hermia on mast cell degranulation and symptom generation in allergic r hinitis to assess its effect and mechanism of action within the nose. Methods: In a randomized, double-blind, placebo-controlled, crossover study, 10 subjects with rhinitis were treated for 30 minutes with loca l hyperthermia or placebo, which was followed 30 minutes later by nasa l allergen challenge. During the first two visits nasal lavages were p erformed to assess vascular leakage and mediator release. During the l ast two visits nasal airway resistance, the number of sneezes, and muc us secretion were monitored. Results: Local hyperthermia significantly reduced both nasal airway resistance (p < 0.05) and vascular leakage (p < 0.02) but had no significant effect on the number of sneezes, on mucus secretion, or on tryptase release. Conclusion: Local hyperthermi a reduces allergen provoked nasal blockage and vascular leakage but ha s no effect on sneezing, rhinorrhea, or tryptase release. Nasal blocka ge occurs predominantly via newly formed lipid mediators and kinins, w hereas sneezing and rhinorrhea occur predominantly via preformed media tors. We propose that local hyperthermia inhibits newly formed mediato r production or release or reduces the sensitivity of the vasculature to inflammatory mediators in general. Further investigation into the m echanisms and potential uses of local hyperthermia is warranted.