Migraine and allergy: a review and clinical update.

Migraine and allergy are both common diseases. Many patients suffer from both, and the vast majority of patients with "sinus headache" complaints are found to have migraine, making migraine identification important to allergists. This review addresses the possibility that allergy and migraine are comorbid conditions, focusing on epidemiology, shared biochemical pathways, and underlying mechanisms. Therapeutic implications of this possible relationship have been the subject of several recent studies, making a review of this association timely and prudent.