LOW DOSE ANTIGEN (LDA) THERAPY
WHAT IS LOW DOSE ANTIGEN THERAPY?
LDA is a method of immunotherapy that involves desensitization with combinations of a wide variety of extremely low dose allergens, given with the enzyme beta-glucuronidase. This induces the production of activated T suppressor cells. It includes mixtures of over 300 allergens that act quite universally, thus decreasing the body’s tendency to overact. The overall success rate of LDA therapy is around 80% but can vary depending on the severity of the condition being treated as well as how long the condition has been present. The better the patient is able to follow the rules (see patient instruction booklet) the better will be the success rate. This treatment is a long-term therapy and the patient must be committed to completing it.
HOW IS LDA GIVEN?
LDA is given by intradermal injections (injections of small amounts of medication just under the skin). Most of the time the location for the injections is in the underside of the forearm, like getting a TB skin test. Usually, injections are given every 2 months, with some exceptions, and then spaced out as symptoms improve. The injections are uncomfortable but the discomfort generally lasts from a few minutes to less than 30 minutes.
ARE THERE ANY CONCERNS IN REGARDS TO SEVERE ALLERGIES (ANAPHYLAXES) OR SEVERE ASTHMA?
Since LDA uses extremely low dose allergens given in an enzyme mixture and appears to be affecting the cell-mediated pathway, the risk of severe adverse reaction is much diminished. There has never been a fatal or life-threatening systemic reaction to LDA treatment; the dosage is simply too low. We do expect to see a localized skin reaction at the injection site that can last a few hours to a few days and slight redness may last up to 3 weeks. Under some circumstances, it is necessary to pretreat patients who have severe symptoms with a steroid medication; this will be discussed prior to initiating therapy.
HOW LONG DOES IT TAKE TO IMPROVE?
The effect of LDA is frequently immediate; however, the full benefit will take longer, especially in patients with long-standing food allergies, chemical sensitivity, or more complex problems. To achieve the full effect of the treatment, which is the amelioration of symptoms, it may require injections every 2-4 months for 2-4 years.
WHAT DOES LDA THERAPY CONSIST OF?
There are 4 different medications that are available to be used and can be given individually or in combination as the case requires.
HOW ARE SEASONAL ALLERGIES SUCH AS HAY FEVER TREATED?
When dealing with seasonal allergies it is necessary to get 1-3 treatments per year. The first dose is recommended to be given 3-4 months before the onset of allergy symptoms and a booster dose about 3 weeks before the season begins for the patient. After the first season, only one booster may be necessary and should be given 3 weeks before the season starts.
*The information on these documents available on the Alpine Clinic web site is not intended to take the place of a consultation with a licensed physician. It is strictly intended for educational purposes, and should not be used to diagnose, cure, prescribe or treat any specific disease.