In severe respiratory distress, mechanical ventilation may be required. In this situation, a tube is placed via the mouth into the air passages to keep the airway open. The tube is connected to a ventilator, providing oxygen directly into the lung. In rare cases, a simple surgery is performed to open an airway.

If blood pressure is dangerously low, medication to increase blood pressure will be given. An intravenous (IV) catheter may be inserted. This is used to give saline solution to help boost blood pressure. The IV line may also be used to give medication. You may need to be admitted to the hospital for further monitoring and treatment.

Epinephrine - Given in severe allergic reactions, epinephrine is extremely effective and fast-acting; it acts by constricting blood vessels, which increases blood pressure, and widening the airway. Epinephrine is given by injection into the muscle, through an IV line, or by injection under the skin.

H1-receptor blockers/antihistamines - Usually diphenhydramine (Benadryl); these drugs do not stop the reaction but relieve some of the symptoms. They may be given by IV, by injection in the muscle, or by mouth. Inhaled beta-agonists (albuterol) - Used to treat bronchospasm (spasms in the lung) and dilate the airways; inhaled.

H2-receptor blockers - Usually cimetidine (Tagamet); given by IV or by mouth. Corticosteroids (examples are prednisone, Solu-Medrol) - These drugs help decrease the severity and recurrence of symptoms; may be given orally, injected in muscle, or by IV line. If low blood pressure does not improve, additional medications, such as dopamine, may be given.

You will usually be observed for at least six hours after the beginning of the reaction. Occasionally, a reaction will seem to get better and then recur, and even worsen, in a few hours. Sometimes the severity of the reaction will require admission to the hospital.

Upon leaving the hospital emergency department, you should immediately obtain the medication prescribed for you. You should carry these at all times to prevent another reaction or lessen its severity.

The epinephrine kit (known as EpiPen or Ana-Kit) should be kept with you at all times in case you are exposed to the antigen that caused the first reaction. The kit contains a premeasured dose of epinephrine in an easy-to-use syringe. As soon as an exposure occurs, you immediately inject the epinephrine into your thigh muscle. This is extremely effective and fast-acting.

Anyone who has experienced an anaphylactic reaction should carry one of these kits after consulting with your physician. Medical attention is always required right away, even if you have treated yourself with epinephrine.