An allergy headache is a headache that stems from an allergic reaction that causes blockage and pain in the sinuses. Allergies may come from a number of sources, including foods, molds, pollen, dust mites, animal dander, smoke, environmental pollution, and chemicals. An allergic reaction triggers a histamine response in the sinus cavities, which are hollow pockets in the forehead, cheekbones, and nasal passages. Those hollow pockets become inflamed during an allergic response, causing pressure and pain.
In an allergic response, immune cells produce histamine that helps to combat the allergen's attack on the body. Excess histamine production leads to vasodilation, in which blood vessels constrict and swell painfully. The sinuses then produce mucus, which drains out of the nose, and nasal passages become inflamed. This inflammation increases pressure in the sinus passages, which can lead to painful swelling and pressure that cause headache.
Allergy headaches are often associated with sinusitis. An allergy headache is caused by a simple blockage causing pressure, though, not a more serious infection in the sinuses. It can be difficult to determine the exact cause of a headache, so sinus headaches are often confused with migraines, cluster headaches, tension headaches, and other types of persistent pain in or near the sinus cavities.
It is not possible to prevent an allergy headache, but people with allergies can take steps to minimize their exposure to known allergens that trigger such headaches. This may mean avoiding situations or areas that cause a reaction, such as homes with pets or foods such as cheese or wine that have been linked to allergic reactions. Allergy medications or shots can help to prevent the histamine response that causes swelling and blockage, but they are not guaranteed to fully prevent an allergy headache.
An allergy headache that seems to come on suddenly after one has been eating could well be an indication of a food allergy, even if the person who has the headache isn't aware of any food allergies he or she may have. A visit to an allergist can help identify such issues and prescribe the appropriate treatment. Making a point to identify and avoid potential allergy foods is among the best ways to ensure that an allergy headache doesn't get the chance to start.
Treatment for an allergy headache also may include antihistamines to limit the histamine response, and decongestants or vasoconstrictors to help reduce inflammation and blockage in the nasal passages. Over-the-counter pain relievers such as ibuprofen or acetaminophen can reduce swelling and the pain caused by sinus pressure. If allergy headaches persist, seek medical attention to address the causes of the allergy and to determine if the pain is caused by an allergy headache or a more serious condition.
