How does immunotherapy work?
The theory behind allergy immunotherapy is helping the body’s immune system build a tolerance to the allergens it currently reacts to. This is done by starting with very small amounts of these allergens taken as shots or drops, and gradually building up to a target dose we know is effective. This takes between one to five months to get to the target dose, depending on the form of immunotherapy you are using, and how your body tolerates it.
Once you reach the target dose, you continue at that dose for three to five years, with important changes taking place in your immune system over that entire time. When you finish with immunotherapy, most people have a three or more years of sustained relief.
Why use immunotherapy?
The other mainstays of allergy treatment – avoiding allergens or using medicines to control symptoms – only make temporary changes. Immunotherapy makes permanent changes in your immune system, helping you develop tolerance to the allergens that cause reactions. Additionally, immunotherapy can decrease the rate at which you develop future allergic sensitivities, and can improve or prevent asthma in allergic children.
What's it like to get allergy shots or drops?
Immunotherapy can be delivered as weekly allergy shorts (injection or subcutaneous immunotherapy, also called SCIT) or daily under-the-tongue treatments (sublingual immunotherapy, or SLIT).
Allergy shots (subcutaneous immunotherapy or SCIT). Your allergy injections are specifically formulated for your allergies. No one else has an allergy vaccine exactly the same as yours.
Allergy shots are given once a week. While climbing to the target dose, these shots must be delivered in the physician’s office, or the office of another physician with the expertise and equipment to treat an allergic reaction. This is because there’s a greater, though still small, chance of an allergic reaction occurring when the dose is being increased.
After you reach your target dose, you or a family member can administer the shots at home. You must agree to stringent safety measures if you choose this option: you must always have auto-injectable epinephrine and liquid antihistamine with you, always have another adult with you for 20 minutes after the shot, and always have a land line or cell phone capable of reaching emergency responders.
Most reactions are just small red areas on the arm. If the redness is any greater than the size of a dime after an injection, or if you have any general symptoms like hives, chest tightness or shortness of breath, call your physician or 911 immediately.
Allergy drops (Sublingual immunotherapy, or SLIT). Sublingual (under-the-tongue) immunotherapy (SLIT) can be used instead of shots. SLIT has been used extensively in Europe, Asia and Australia for the last 30 years, but only recently in the United States. It’s been shown to be highly effective in treating allergies.
As with allergy shots, your SLIT vaccine is mixed specifically for you, with only the allergens to which you are sensitive. You would receive your very first dose at the office, and thereafter take your daily drops (even during your escalation) at home. This is because SLIT is even safer than allergy shots. When you are at your target dose, you’ll be using your allergy drop vial to deliver three squirts under the tongue. You’ll hold these there for two minutes then swallow the dose.
Some people experience mild tingling or itching in the mouth with SLIT. The chances of a serious reaction are very small.