LOS ANGELES—Migraine frequency and headache-related disability are greater among migraineurs with rhinitis than among migraineurs without rhinitis, according to two studies presented at the 54th Annual Scientific Meeting of the American Headache Society. The increases are particularly pronounced among migraineurs with a mixture of allergic and nonallergic rhinitis, which is called mixed rhinitis, said Vincent T. Martin, MD, Clinical Professor of General Medicine at the University of Cincinnati.
“The differences between the rhinitis and control groups were most evident in the highest percentiles of migraine frequency,” said Dr. Martin. “This could imply that the association between rhinitis subtypes and migraine frequency and disability is most pronounced in those with more frequent migraines.”
Rhinitis Subtypes Among Migraineurs
To evaluate whether rhinitis is associated with increased headache frequency and headache-related disability in persons with migraine, Dr. Martin and his colleagues analyzed data from the American Migraine Prevalence and Prevention (AMPP) study. From 2005 to 2009, 6,008 migraineurs responded to annual follow-up surveys, which included questions about frequency of headache days per month and headache-related disability, as measured by the Migraine Disability Assessment (MIDAS) questionnaire.
Based on the presence of two or more rhinitis symptoms, respondents were categorized into rhinitis and nonrhinitis groups. The rhinitis group was categorized into patients with allergic rhinitis, nonallergic rhinitis, mixed rhinitis, and unclassified rhinitis based on the presence or absence of specific allergic (eg, cats, dogs, mold) and nonallergic (eg, perfumes, cigarette smoke, weather) triggers. The study’s primary outcome measures were headache frequency categories (ie, 0–4, 5–9, 10–14, and 15 or more days of headache per month) and MIDAS categories (ie, 0–5, 6–10, 11–20, and more than 20 days of disability per three months).
In a second clinic-based study, Dr. Martin reviewed data from the Migraine, Allergy, and Rhinitis Study (MARS) to ascertain whether levels of migraine frequency and disability differed between patients with allergic, mixed, and nonallergic rhinitis. A total of 301 rhinitis patients were recruited from an allergy clinic, and a group of 65 controls were obtained from a primary care practice site. Eligible participants were between the ages of 18 and 65 and had been diagnosed with migraine.
Rhinitis patients were later subcategorized into those with allergic (99), mixed (143), and nonallergic (59) rhinitis, based on allergy testing and responses to a questionnaire of nonallergic triggers. Control patients completed a rhinitis questionnaire and reported infrequent or rare rhinitis symptoms to allergic and nonallergic rhinitis triggers. All participants took part in a verbal headache diagnostic interview and were later assigned a headache diagnosis by a headache specialist blinded to participants’ rhinitis diagnosis. Patients reported their migraine frequency in days per month and took the MIDAS test to measure their headache-related disability.
Mixed Rhinitis Was Associated With Headache Frequency and Disability
Approximately 65% of participants in the AMPP study had rhinitis. A total of 737 patients had allergic rhinitis, 379 had nonallergic rhinitis, 1,869 had mixed rhinitis, and 924 had unclassified rhinitis. The nonrhinitis group comprised 1,940 individuals.
Headaches were more frequent in subjects with rhinitis (odds ratio, 1.30) overall than in controls. Among rhinitis subtypes, headache frequency was significantly higher in patients with mixed rhinitis and unclassified rhinitis (odds ratios of 1.37 and 1.33, respectively). Individuals with rhinitis also were more likely to have higher MIDAS scores (odds ratio, 1.32) than controls. Among rhinitis subtypes, increased likelihood of higher MIDAS scores was significant only for participants with mixed rhinitis (odds ratio, 1.47).
In the MARS study, migraine frequency and disability were significantly higher at the 25th, 50th, and 75th percentiles of these measures for each of the rhinitis subtypes, compared with controls. Differences with controls were numerically higher among patients with mixed and nonallergic rhinitis than among patients with allergic rhinitis.
Migraineurs with allergic rhinitis experienced 0.37, 0.62, and 1.5 additional days of migraine per month, compared with controls, at the 25th, 50th, and 75th percentiles, respectively. Participants with mixed rhinitis experienced 0.67, 1.00, and 3.43 additional headache days per month, compared with controls, at the 25th, 50th, and 75th percentiles, respectively.
Afferent Neurons in the Nose May Trigger Migraine
“The pathophysiology of migraine headache has focused on the activation of afferent trigeminal neurons in the dura. Our results could indicate that the afferent trigeminal neurons in the nose or paranasal sinuses also could play a role in triggering a migraine attack,” Dr. Martin told Neurology Reviews. “The nose is the only exposed mucosa in the body and is primed to sense chemical and allergic triggers in the environment. Why couldn’t it be involved in migraine pathogenesis? Therapies that block allergies, such as immunotherapy (allergy shots), and nasal antihistamines or steroids should be studied to determine whether they decrease the frequency of headaches in migraineurs.”