Sinusitis is an infection or inflammation of the sinuses. A sinus is a hollow space. There are many sinuses in the body, including four pairs inside the skull. They serve to lighten the skull and give resonance to the voice. These sinuses are lined with the same kind of tissue that lines the inside of the nose. The same things that can cause swelling in the nose—such as allergies or infection—can also affect the sinuses. When the tissue inside the sinuses becomes inflamed, mucus discharge is increased. Over time, air trapped inside the swollen sinuses can create painful pressure inside the head. This is a sinus headache.
Urticaria is the medical term for hives, a common allergic reaction that affects about 20% of people at some point in their lives. There are many triggers for hives, but the symptoms include itchy patches of skin that become swollen red welts. Itching can be mild to severe, and may be made worse by scratching, alcoholic beverages, exercise, and stress.
Many people are aware of their triggers for hives, such as eating foods including shrimp or peanuts which cause the allergic reaction within a short time. For others, there are so many possible causes of hives it requires allergy testing by a physician. In a small number of cases the cause may never be identified.
An appointment with a board-certified allergist can help determine the severity and cause of the problem. The allergist will discuss your medical history and symptoms and may use blood or skin tests to find out whether you have an allergy and what the allergen is. Medications (over-the-counter and prescription) and immunotherapy (allergy shots) may provide relief; making changes to your environment can also be helpful. To learn more about specific types of allergies and their symptoms, visit the page that relates to your situation: