Allergy shots are given to some people who have persistent and disruptive allergy symptoms. The shots do not treat symptoms, but by altering the immune response they prevent future reactions. (This is referred to as immunotherapy.) Treatment involves a series of shots, each containing a slightly greater amount of the antigen(s) that cause the reaction. Ideally, the person will become "desensitized" to the antigen(s) over time. The effectiveness of shots varies by individual.

Anti-allergy medications are of many types. The choice of medication and how it is given depends on the severity of the reaction.

For relief of long-term allergies such as hay fever or reactions to dust or animal dander, the following medications may be prescribed.

Long-acting prescription antihistamines, such as cetirizine (Zyrtec), fexofenadine (Allegra), and loratadine (Claritin), can relieve symptoms without causing sleepiness. They are meant to be taken for months at a time, even indefinitely. Most have to be taken only once a day and last for 24 hours.

Nasal corticosteroid sprays are widely prescribed for nasal symptoms not relieved by antihistamines. These prescription medications work very well and are safe, without the side effects of taking steroids by mouth or injection. These sprays take a few days to take effect, and must be used every day. Examples are fluticasone (Flonase), mometasone (Nasonex), and triamcinolone (Nasacort).

In some people, cromolyn sodium nasal spray prevents allergic rhinitis, inflammation of the nose that occurs as an allergic reaction. Decongestants can restore sinus drainage, relieving symptoms such as nasal congestion and swelling and runny nose and sinus pain (pain or pressure in the face, especially around the eyes). They are available in oral forms and as nasal sprays. They should be used for only a few days, as they may have side effects such as high blood pressure, rapid heartbeat, and nervousness.

Self-care at home is not enough in severe reactions. A severe reaction is a medical emergency. Do not attempt to treat or "wait out" severe reactions at home. Go immediately to a hospital emergency department. If no one is available to drive you right away, call 911 for emergency medical transport. For more information on what to do in a severe reaction, see Anaphylaxis.

An oral antihistamine, such as diphenhydramine (Benadryl). Caution these may make you too drowsy to drive or operate machinery safely. They can affect concentration and interfere with children's learning in school. These medications should be taken for only a few days. For rashes, an anti-inflammatory steroid cream such as hydrocortisone