WHAT IS ALLERGY SHOTS?
Allergy shots consist of a series of injections into the fatty tissues underneath the skin (usually in the upper arms) to decrease your sensitivity to allergy-causing substances (allergens). It is a method whereby the immune system is trained to no longer react to the allergens that once caused allergic symptoms. The injections are made of patient-specific allergens which have been purified and sterilized into an injectable form.
WHICH ALLERGIES CAN BE TREATED WITH ALLERGY SHOTS?
Allergy shots can be given to patients who are allergic to airborne allergens such as pollens (trees, grasses, weeds, etc.), dust mites, molds, cats, dogs, and cockroaches, or certain stinging insects.
WHO SHOULD RECEIVE ALLERGY SHOTS?
To qualify for allergy injections, you must have documented allergies based on either positive skin tests or blood tests. Allergy shots are provided to allergic patients whose symptoms are not easily controlled by allergen avoidance and medications. Allergy shots can benefit patients suffering from allergic rhinitis, eye allergy, allergic asthma and stinging insect allergy.
HOW IS ALLERGY SHOTS ADMINISTERED?
Since allergy shots contain allergens, they must be started at a very low dose. This dose is gradually increased on a weekly basis during a “build-up phase” until a therapeutic dose (the “maintenance dose”) is reached. The build-up phase usually takes about 6-8 months. The exact length depends on degree of individual allergic sensitivity. If the dose was to be started too high or increased too fast, allergic reactions might occur. Once the maintenance dose is reached, the injections can be given every 2 weeks. The interval between injections eventually can be increased to every 4 weeks.
HOW LONG SHOULD ALLERGY SHOTS BE ADMINISTERED?
A course of allergy shots takes 3-5 years. If the injections are stopped prematurely, recurrent symptoms usually develop in a few months. After completing a full course of injections, many patients will have prolonged or permanent relief of the symptoms. Some patients, however, may gradually become symptomatic again and may require an extended course of injections.
HOW SOON DO ALLERGY SHOTS TAKE EFFECT?
Once allergy shots are started, they usually take 6-12 months for a reduction in symptoms to be noted. If scheduled doses are frequently missed, the beneficial effect may be delayed.
HOW EFFECTIVE ARE ALLERGY SHOTS?
Approximate 80-85% of allergic individuals receiving allergy shots get significant improvement of their symptoms. This means that symptoms are reduced (but not necessarily that they will completely disappear). Follow-up evaluations will be done periodically to monitor progress and to determine if immunotherapy has been effective.
WHAT ARE THE SIDE EFFECTS OF ALLERGY SHOTS?
The most common side effect is localized itching, swelling or tenderness at the sites of the injections. These reactions may be treated by applying ice or hydrocortisone cream to the injection sites. Taking an antihistamine such as Zyrtec, Allegra or Claritin may also be helpful. If the reaction persists more than 24 hours or if the reaction size is greater than the size of a quarter, your nurse or doctor should be notified at the next visit.
A more serious systemic reaction may occur from administration of allergy shots. However, these reactions are rare. Symptoms of a systemic reaction include generalized itchiness, runny nose, nasal congestion, sneezing, coughing, wheezing, tightness in the throat or chest, hives, swelling of the face / tongue or throat, lightheadedness, faintness, or even shock. These reactions usually occur within the first 30 min after the injection. But occasionally, they may start after 30 min. Therefore, for your safety, you MUST wait in the office 30 min after receiving allergy shots. Severe reactions are treated with injection of epinephrine, which normally acts promptly to reverse the reactions. Occasionally, additional medications are required as well.
WHAT CAN BE DONE TO LESSEN THE CHANCE OF A SYSTEMIC REACTION?
You should notify your doctor or nurse of any adverse reaction that you have experienced after the last injection, including how big the local swelling is and how long it lasts. In addition, if you are having increased asthma symptoms, an upper respiratory tract infection with fever, or significant allergy symptoms, you must be examined by the doctor before allergy shots can be safely administered. Finally, please notify your doctor of any changes in your medications.
ARE THERE ANY MEDICATIONS THAT CANNOT BE TAKEN WHILE RECEIVING ALLERGY SHOTS?
There is a group medications called “beta blockers” that should not be taken while you are on allergy shots. These medications are commonly prescribed for high blood pressure, heart conditions and migraine headaches. Some commonly prescribed “beta blockers” are Acebutolol (Sectral), Atenolol (Tenormin), Atenolol / Chlorthalidone (Tenoretic), Betaxolol (Kerlone), Bisoprolol (Zebeta), Bisoprolol / Hydrocholorthiazide (Ziac), Labetalol (Trandate), Metoprolol (Toprol, Lopressor), Nadolol (Corgard), Nadolol / Bendroflumethiazide (Corzide), Penbutolol (Levatol), Pindolol, Propranolol (Inderal, Inderide, InnoPran), Timolol (Blocadren), and Timolol / Hydrochlorothiazide (Timolide). If you are not sure if the medications you are taking are “beta blockers”, please ask your doctor. These medications will increase the possibility of a systemic reaction and will interfere with the doctor’s ability to reverse the reaction.
For more information:
http://www.acaai.org/allergist/allergies/Treatment/allergy-immunotherapy-shots/Pages/default.aspx