title: A lost track in ICHD 3 beta: A comprehensive review on osmophobia.
abstract: Background Osmophobia (Os) has been reported to be much more prevalent in migraine (M) than in other primary headaches, and its high specificity in the differential diagnosis between M and tension-type headache (TTH) has been reported. Os was included in the ICHD II Appendix as a diagnostic criterion of M. It disappeared in ICHD-3 beta. To understand this choice, we reviewed the literature after 2004. Methods This was a systematic review. We searched in PubMed, MEDLINE and Cochrane library for "osmophobia", "odour/odorphobia AND headache", "odour/odor hypersensitivity AND headache" and "olfactory hypersensitivity AND headache". Results 112 papers cited Os as an accompanying symptom of headache; 16 focused on Os in M diagnosis. With the data from 40 articles, we calculated the pooled prevalence of Os in 14,360 patients (2281 pediatric) affected by M (n = 12,496) and TTH (n = 1864). In M, the prevalence was 48.5% (CI 95% 41.4 to 55.8%) in adults and 23.4% (CI 95% 15.7 to 33.4%) in pediatric patients; in TTH, the prevalence was 8.9% (CI 95% 4.6 to 13.5%) in adults and 7.9% (CI 95% 3.3 to 18.1%) in pediatric patients. Ten of these papers allowed us to calculate the sensibility and specificity of Os in differential diagnosis between M and TTH. In adults, the value of specificity was 94.1% (CI 95% 88.9 to 96.9%), and sensitivity was 51.4% (CI 95% 38.4 to 64.2%). In pediatric patients, specificity was 92.0% (CI 95% 81.9 to 96.7%), and sensitivity was 22.1% (CI 95% 10.1 to 41.8%). Conclusion The literature endorses the inclusion of Os among M diagnostic criteria. On this ground, the decision to remove Os from ICHD 3 beta appears unjustified and a revision of this choice is recommended.
authors.affiliation: 1 Interdepartmental Headache Centre, School of Medicine, University of Padua, Padua, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Zanchin
authors.affiliation: 1 Interdepartmental Headache Centre, School of Medicine, University of Padua, Padua, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Fuccaro
authors.affiliation: 1 Interdepartmental Headache Centre, School of Medicine, University of Padua, Padua, Italy.
authors.forename: Pierantonio
authors.initials: P
authors.lastname: Battistella
authors.affiliation: 1 Interdepartmental Headache Centre, School of Medicine, University of Padua, Padua, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Ermani
authors.affiliation: 2 Headache Centre, Neurological Division, SS Giovanni e Paolo Hospital, Venice, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Mainardi
authors.affiliation: 1 Interdepartmental Headache Centre, School of Medicine, University of Padua, Padua, Italy.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Maggioni
mesh_terms: D003937:Diagnosis, Differential; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards*; D008881:Migraine Disorders / Q000145:classification* / Q000175:diagnosis; D000857:Olfaction Disorders / Q000145:classification* / Q000175:diagnosis; D010698:Phobic Disorders / Q000145:classification* / Q000175:diagnosis; D018781:Tension-Type Headache / Q000145:classification / Q000175:diagnosis
keywords: Migraine; differential diagnosis; odors; primary headaches; tension-type headache