Osmophobia and Odor-Triggered Headaches in Children and Adolescents: Prevalence, Associated Factors, and Importance in the Diagnosis of Migraine.

OBJECTIVE: The objectives of this study are to study osmophobia and odor-triggered headaches among headache pediatric patients. BACKGROUND: Achieving the correct diagnosis for headaches in younger children can be challenging. The presence of osmophobia could constitute a helpful piece of information for making the correct diagnosis of headaches among adults. METHODS: This was a cross-sectional study. Children and adolescents with headaches who were seen consecutively at a pediatric outpatient service and had at least 1 headache attack over the previous 12 months were included. We used a semi-structured questionnaire, Pediatric Migraine Disability Assessment, State-Trait Anxiety Inventory, and Children's Depression Inventory. RESULTS: About 300 patients were included; 253 had migraine, 47 had a tension-type headache; 137 had osmophobia during headaches (135 were migraineurs). "Osmophobia during headaches" for diagnosing migraine: Sensitivity: 54.4% (95% CI: 48.2%-60.5%); specificity: 95.8% (95% CI: 85.8%-98.8%); positive predictive value (PPV): 98.5% (95% CI: 94.8%-99.6%); negative predictive value (NPV): 28.5% (95% CI: 22.0%-36.0%). Osmophobia was associated with higher intensity (OR: 2.90; 95% CI: 1.63, 5.15; P < .001) and duration of the headache (OR: 5.73; 95% CI: 2.29, 14.3; P < .001) and with vomiting (OR: 3.56; 95% CI: 1.83, 6.96; P < .001) (logistic regression). There were 62 patients (all of them migraineurs) with odor-triggered headaches: sensitivity for diagnosing migraine: 24.9% (95% CI: 19.9%-30.6%); specificity: 100% (95% CI: 92.4%-100%), PPV: 100% (95% CI: 94.8%-100%), NPV: 20% (95% CI: 16%-26.0%). Odor-triggered headaches were associated with higher intensity (OR: 3.47; 95% CI: 1.64, 7.35; P = .001) and duration of the headache (OR: 3.28; 95% CI: 1.37, 7.86; P = .001), vomiting (OR: 2.37; 95% CI: 1.19, 4.74; P = .014), and phonophobia (OR: 2.40; 95% CI: 1.08, 5.32; P = .031) (logistic regression). Osmophobia was associated with higher-impact migraine (OR: 4.65; 95% CI: 1.30, 16.6; P = .018) and emergency care (OR: 4.65; 95% CI: 1.81, 12.0; P = .001) (logistic regression). CONCLUSIONS: Osmophobia and odors as triggers for headaches are useful in diagnosing migraine and are markers for the severity of migraine in the pediatric population.