A new study finds that many people with allergic rhinitis also suffer from migraines, suggesting that the compound that causes allergies, histamine, may also be responsible for migraines. Researchers studied nearly 300 adults and children and found that 34 percent of people with allergic rhinitis also had migraines. Allergic rhinitis is commonly known as hay fever. Only 4 percent of the people studied who did not have allergic rhinitis had migraines. The researchers, in an article in The Chronicle of Allergy: Asthma and Immunology, said the finding could prompt doctors to “raise awareness” that people with allergic rhinitis may suffer from migraines. Past studies have found that many patients with periodic migraines are misdiagnosed with sinus headaches, which can lead to mis-treatment. Sinus headaches occur when the sinus cavity is inflamed, and allergies are one of the causes. Because of the similarities between the symptoms of sinus headache and migraine, it is really difficult to distinguish between the two. The symptoms of migraine are a throbbing pain on one or both sides of the head, although it is usually on one side of the head, and is accompanied by nausea and sensitivity to light and sound. But migraine sufferers can also have symptoms of sinus headaches such as increased facial pressure and nasal congestion. Researchers found that patients with allergic rhinitis were 14 times more likely to have migraine symptoms. Researchers believe that when allergies occur, the body’s immune system releases histamine, which causes inflammation and the swelling of blood vessels that can lead to migraines. Distinguishing migraines in sinus headaches is critical in treatment. Migraines can be treated by taking common painkillers, but a series of medications called tritane (triptan) is necessary to treat migraines. And periodic migraines must be prevented by taking medication. The researchers noted that there is no evidence that antihistamines for hay fever can relieve migraine symptoms. The researchers believe this is not surprising, as antihistamines do little to relieve the swelling of blood vessels caused by histamine.