Three types of headaches may possibly be related to allergic disease - "sinus headaches" (facial pain), migraines and cluster headaches.
What are the symptoms of "sinus headache"?
The four groups of sinus cavities in the head are hollow air spaces with openings into the nose for exchange of air and mucus. They're located inside each cheekbone, behind the eyes, behind the bridge of the nose and in the forehead. Secretions from the sinus cavities normally drain into the nose.
Sinus headaches and pain occur when the sinuses are swollen and their openings into the nasal passages are obstructed, stopping normal drainage and causing pressure to build up. Often the pain is localized over the affected sinus, perhaps causing facial pain rather than a headache. For example, if the maxillary sinus in the cheeks is obstructed, your cheeks may be tender to the touch and pain may radiate to your jaw and teeth. Other sinuses can cause pain on the top of your head, or elsewhere. Sinus pain can be dull to intense, often begins in the morning and becomes less intense after you move from a lying down to an upright position.
Similar pain can also be caused by severe nasal congestion, particularly if you have a septal deviation or septal "spur" from a previous nasal injury. Such "headaches" or facial pain can involve one side only.
Oral or nasal spray decongestants often help relieve symptoms of facial pain or headaches due to nasal or sinus blockage. Antihistamines are generally less helpful. Obstructed sinuses can get infected, requiring more intensive treatment, including antibiotics.
One hint that allergy might play a role in your sinus headaches or facial pain is if you have other upper airway symptoms such as the itching, sneezing and runny nose of seasonal allergic rhinitis (hay fever). Allergy is not usually a direct cause of these types of headaches when the other allergic rhinitis symptoms are not present. Allergic reactions to things like airborne pollens, dust, animal dander, molds, as well as foods, can lead to sinus obstruction. Treatment of the underlying allergic cause of sinus pain can result in long-term relief. Medications used to treat allergies include antihistamines, decongestants, intranasal steroids and cromolyn. In some cases, allergen immunotherapy (allergy shots), may be recommended. When possible, of course, avoid the allergen if an avoidable substance causes your allergy.