The Effect of the Emotion of Happiness on Allergic Skin Wheal Responses and Plasma Levels of Neuropeptides and Nerve Growth Factor in Patients with Allergic Rhinitis

Abstract

Objectives: The effect of the emotion of happiness on allergic responses and plasma levels of neuropeptides and neurotrophins was studied in patients with allergic rhinitis. Patients and Methods: 27 patients with allergic rhinitis and 27 normal subjects who passed the entrance examination to university were studied. One day before, 1 h before and soon after the announcement of the results of the entrance examination, skin prick tests by Japanese cedar pollen, house dust mite and histamine were performed, and simultaneously plasma levels of substance P (SP), vasoactive intestinal peptide (VIP), nerve growth factor (NGF) and neurotrophin 3 (NT-3) were measured. Results and Conclusion: Happiness induced by passing the entrance examination to university reduced skin wheal responses induced by Japanese cedar pollen and house dust mite, while it had no effect on skin wheal responses induced by histamine in patients with allergic rhinitis. Happiness also reduced the plasma levels of SP, VIP and NGF, but not NT-3, in patients with allergic rhinitis. In contrast, happiness had no effect on skin wheal responses induced by histamine or plasma levels of SP; VIP, NGF or NT-3 in normal subjects. These results indicate that happiness may reduce allergen-induced wheal responses in association with a decrease in SP, VIP and NGF but not NT-3. This finding may be useful in elucidating the neuroimmunology and treatment of allergic rhinitis.