AUTHOR=Gossrau Gudrun , Zaranek Laura , Klimova Anna , Sabatowski Rainer , Koch Thea , Richter Matthias , Haehner Antje 

TITLE=Olfactory training reduces pain sensitivity in children and adolescents with primary headaches

JOURNAL=Frontiers in Pain Research

VOLUME=Volume 4 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/pain-research/articles/10.3389/fpain.2023.1091984

DOI=10.3389/fpain.2023.1091984

ISSN=2673-561X

ABSTRACT=Objective: Headache prevalence among children and adolescents increased over the last years. Evidence-based treatment options for pediatric headache remain limited.
Research suggests positive influence of odors on pain and mood. We investigated the effect of repeated exposure to odors on pain perception, headache related disability and olfactory function in children and adolescents with primary headaches.
Methods: 80 patients with migraine or tension type headache (mean 13,1± 3,29 years) participated, 40 underwent daily olfactory training with pleasant odors for three months, 40 received state of the art outpatient therapy as control group. At baseline and follow up three months later, olfactory function (odor threshold, odor discrimination, odor Identification, comprehensive TDI score), mechanical detection and pain threshold (Quantitative Sensory Testing), electrical pain threshold, patient reported outcomes on headache-related disability (PedMIDAS), pain disability (PPDI) and headache frequency were assessed. 
Results: Training with odors increased significantly electrical pain threshold compared to the control group (U = 470,000; z = -3,177; p = 0,001). Additionally, olfactory training increased significantly olfactory function (TDI score (t(39) = -2,851; p = 0,007), in particular olfactory threshold compared to controls (U = 530,500; z = -2,647; p = 0,008).  Headache frequency, PedMIDAS and PPDI decreased significantly in both groups without a group difference.
Conclusions: Exposure to odors has a positive effect on olfactory function and pain threshold in children and adolescents with primary headache. Increased electrical pain thresholds might reduce sensitization for pain in patients with frequent headaches. The additional favourable effect on headache disability without relevant side effects underlines the potential of olfactory training as valuable non-pharmacological therapy in pediatric headache.