A study published within the journal Scientific Reports has categorized migraine-associated odors into six groups and observed that odors of cleansing products can significantly increase migraine attacks in patients with chronic migraines.

Study: Classification of odors related to migraine attacks: a cross-sectional study. Image Credit: fizkes/Shutterstock.com

Background

Migraine is a standard neurological disease characterised by strong headache, typically on one side of the pinnacle. In Japan, the prevalence of migraine is 8.4%. Certain aspects, including stress, fasting, weather, sleep disturbance, hormones in women, light, sound, and odors, are known to extend migraine attacks.

Increased sensitivity to odor is taken into account a selected symptom of migraine, which is incessantly observed in 95% of migraine patients. There may be evidence showing that certain forms of odors are particularly related to migraine attacks.

Mechanistically, odor signal is received by the brain through the olfactory bulb, and studies have shown that odors trigger migraine by activating different brain regions.

In the present study, scientists have categorized migraine-associated odors and determined their correlation with clinical characteristics.

Study design

The study was conducted on a complete of 101 patients with clinical migraine. The participants were supplied with a questionnaire comprising 35 items of odors chosen based on previous evidence.

The questionnaire was used to find out which forms of odors triggered migraine attack and the way the participants protected themselves from the odors.

Moreover, the scientists conducted an element evaluation to find out common aspects of odors related to migraine attacks. Factor evaluation is a statistical method that reduces a big set of variables right into a smaller set of things by extracting all commonalities from the variables.

Essential observations

About 16% and 84% of the study population were present with chronic and episodic migraine, respectively. Amongst participants with chronic migraine, 75% had concomitant medication overuse headache. An association between odor and migraine attack was observed in 78% of participants.

Greater than 50% of participants reported perfume odor as a trigger of migraine attack. This was followed by odors of tobacco, fabric softener, body, garbage, hairdressing product, automobile, and sweat. Not one of the participants reported lemon, tangerine, or apple odor as a migraine trigger.

Aside from 35 items of odors included within the questionnaire, ikebana (a Japanese art of flower arrangement) and gasoline were probably the most commonly reported odors related to migraine attack.

Besides forms of odors, the study determined common places related to migraine attack. Greater than 50% of the participants reported office as a standard place related to migraine attack.

This was followed by home, restaurant, and hospital waiting room. Not one of the participants identified consultation or examination room as a spot related to migraine attack.

Aside from migraine-associated locations included within the questionnaire, train, town, and departmental stores were probably the most commonly reported places related to migraine attack.

Regarding preventive measures against odors, about 42%, 23%, and 22% of the participants reported wearing mask, using air cleaner, and using deodorant spray, respectively. As well as, about 17% and 5% of the participants reported moving out of the place and covering the nose with a handkerchief, respectively, to forestall odors.

Considering participant’s age, a significantly high rate of migraine attack attributable to tobacco or soap odor was observed amongst younger participants. Considering gender, migraine attack attributable to body odor or garbage was observed only in female participants.

Considering forms of migraine, participants with chronic migraine showed higher susceptibility to fabric softener, sweat, socks, coffee, excrement, vomit, and animal odors in comparison with those with episodic migraine.

Based on the factor evaluation, six common aspects of the odors were identified. Factor one was fetid odor; factor two was cooking products; factor three was oil derivatives and others; factor 4 was shampoo and conditioner; factor five was cleansing products; and factor six was perfumes, insecticides, and rose.    

Factor five, which also included flora-based hair styling preparations, laundry detergents, and fabric softeners with floral fragrances, showed significantly higher association with migraine attacks in chronic migraine patients than that in episodic migraine patients.

Study significance

The study identifies six groups of odorant substances that may trigger migraine attack in patients with chronic or episodic migraine.

Nonetheless, chronic migraine patients can have higher susceptibility to some chemicals with floral fragrance.