Having allergies could make headache symptoms worse for people who experience migraines, according to a new study.
The research, published in the journal Cephalalgia, showed that people with both migraines and rhinitis experience more frequent headaches compared with people who have migraines but not rhinitis.
"We are not sure whether the rhinitis causes the increased frequency of headaches or whether the migraine attacks themselves produce symptoms of rhinitis in these patients," study researcher Vincent Martin, M.D., a professor of medicine at the University of Cincinnati, said in a statement. "What we can say is if you have these symptoms, you are more likely to have more frequent and disabling headaches."
Martin worked on the study with colleagues from Montefiore Medical Center, Vedante Research and the Albert Einstein College of Medicine of Yeshiva University. Nearly 6,000 people with migraines who were part of the American Migraine Prevalence and Prevention Study were included in the study, and were asked "Do you suffer from nasal allergies, seasonal allergies or hay fever?" An answer of yes indicated that they had rhinitis.
Researchers found that two-thirds of the people with migraine in the study also had rhinitis. They also found that headache frequency was 33 percent greater among people who experienced migraine and rhinitis, compared with just migraine.
People who had "mixed rhinitis" -- meaning their allergy symptoms are triggered by not only known triggers like cats and dogs and tree pollen, but also non-allergic triggers like perfume, weather and cigarette smoke -- seemed to have it the worst. Those with mixed rhinitis had a 45 percent higher risk of experiencing more frequent headaches and a 60 percent higher risk of experiencing more disabling headaches, compared to migraineurs without rhinitis.
"The nose has largely been ignored as an important site involved in the initiation and exacerbation of migraine headache," study researcher Richard Lipton, M.D., of Montefiore Medical Center and the Albert Einstein College of Medicine, said in a statement. "If rhinitis exacerbates migraine, as these results suggest, treating rhinitis may provide an important approach to relieving headache in people with both disorders."
Both migraines and allergies are common conditions, with anywhere from a quarter to half of Americans experiencing allergies and around 12 percent of Americans experiencing migraine.
Correction: A previous version of this article misstated the name of study researcher Dr. Richard Lipton. It has been corrected.