Headaches may be related to allergic rhinitis in a number of ways. First, patients with severe nasal congestion may have swelling of the openings to the paranasal sinuses, called “ostia.” This swelling may cause intermittent or persistent closure of the sinus, resulting in an inability to equalize pressure within the sinus cavity.
Symptoms related to sinus pressure include pain or pressure over the forehead, between the eyes, or over the cheeks, brought on or aggravated by changes in barometric pressure (flying, driving into the mountains, or during weather changes) or while bending forward. These headaches often respond to medications that effectively reduce nasal swelling, such as intranasal steroids. Second, many patients with allergic rhinitis have some degree of concomitant chronic sinusitis.
In these cases, the sinuses may be persistently blocked or filled with inflammatory tissue and/or active infection. Typically, in these patients, a number of symptoms and signs will be present, such as thick, discolored postnasal drip, sore throat, and/or cough. Third, a significant minority of patients with allergic rhinitis suffer from migraine headaches, which may be triggered or aggravated by nasal swelling.
In addition, some patients with allergic rhinitis may also suffer from food allergies, which may provoke migraines. Finally, some patients who use intranasal medications complain that putting any type of nasal spray into their nose directly triggers a headache. Each of these various mechanisms should be considered in all patients who suffer from allergic rhinitis and headaches, and patients should be treated accordingly.