Classification of odorant substances that trigger migraine attacks: a cross-sectional study

Abstract Background Migraine is a common primary headache disorder that can be induced by various factors such as stress, hormones in women, fasting, weather, and sleep disturbance. Odorant substances are also common triggers of migraine attacks. We aimed to categorize odorant substances that trigger migraine and explore their relationships with clinical characteristics. Methods A total of 101 migraineurs were included in our study. A questionnaire was used to determine the types of odorant substances that triggered migraine attacks. We performed factor analysis to explore the common factors of the odorant substances and the relationship between these factors and the clinical characteristics. Results The factor analysis estimated six common factors. We defined factor 1 as fetid odor, factor 2 as cooking products, factor 3 as oil derivatives and others, factor 4 as shampoo and conditioner, factor 5 as hair styling preparation and cleaning products, and factor 6 as perfumes, insecticides, and rose. Factor 5 also included hair styling preparation, laundry detergent, and fabric softener, usually added with floral fragrances. It was more likely to trigger migraine attacks in chronic than in episodic migraine patients (p = 0.037). Conclusion Our study showed that odorant substances that trigger migraine attacks could be categorized into six groups and suggested that some chemicals were more likely to trigger migraine attacks in patients with chronic migraine than in those with episodic migraine.