A lost track in ICHD 3 beta: A comprehensive review on osmophobia.

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.

Endothelin receptor A -231 G>A polymorphism: no linkage to primary pediatric headache.

OBJECTIVE: To assess whether the biallelic -231 G>A polymorphism of the endothelin type A receptor (EDNRA) gene, previously shown to be a marker of increased risk for developing migraine, has a role in the susceptibility to primary pediatric headache. BACKGROUND: Several studies suggest that endothelin has a role in migraine. A recent association study has shown that the biallelic -231 G>A polymorphism of the EDNRA gene is associated to migraine in an elderly population. METHODS: A total of 126 consecutive unrelated pediatric patients affected by primary headache, classified according to the International Headache Society criteria in migraine (migraine with aura, n = 3; migraine without aura, n = 80), and tension-type headache (episodic tension-type headache, n = 36; chronic tension-type headache, n = 7) patients, were recruited to the study. Sixty-seven healthy blood donors were used as a control group. Genomic DNA was extracted from buccal swabs or blood samples and analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the above-mentioned polymorphism. Allele and genotype frequencies for primary headache patients were analyzed in comparison with the control group. RESULTS: No significant differences were found in the distribution of the EDNRA -231 G>A polymorphic variant when considering both genotype (migraine chi2 = 2.78, P = .25; tension-type headache chi2 = 3.58, P = .17) and allelic frequencies (migraine chi2 = 1.48, P = .22; tension-type headache chi2 = 0.39, P = .56). Furthermore, no significant genotype-related difference was found in relation to clinical features, such as age at onset, frequency, and length of the attacks. CONCLUSIONS: Our study shows that the -231 G>A polymorphism in the EDNRA gene is neither associated with primary juvenile headache nor significantly correlated with main clinical features characteristic of the headache pathology in pediatric settings.