An allergy shot schedule that compresses six months of treatment into a single two-and-a-half hour office visit is safe, rapidly effective, and a heck of a lot cheaper than conventional allergy shot programs, say doctors at a meeting of allergy specialists.
Traditional allergy shots are customized for individual patients. They consist of weekly injections of watered-down concentrations of the substances called allergens that trigger allergy symptoms: sneezing, congestion, runny nose, fatigue, and other miseries. Usually, it takes several months of injections of increasingly larger concentrations of allergens before patients reach their "maintenance" dose, after which they continue to receive injections every two to four weeks for three to five years.
Eventually, the patient's immune system, which triggers the allergy symptoms, learns to tolerate the offending allergens -- whether pollen, animal dander, dust, or other substance -- and the allergy symptoms subside. But it may take up to a year in some cases before the patient begins to experience a real benefit, and that means a lot of shots, a lot of office visits, and a lot of money.
An alternative to the gradual build-up phase is a procedure known as rapid allergen vaccination (RAV), or "rush immunotherapy." In this procedure, patients are built up to their maintenance dose in a matter of hours rather than months. But because the patients get a lot of allergens in a short span of time, typically two to three hours, some caregivers are concerned the procedure can cause a serious type of allergic reaction called anaphylaxis, in which an overactive immune system releases chemicals that can cause swelling and constriction of the airways, rapid heart beat, a sudden drop in blood pressure, loss of consciousness, and even death.
'Rush' Allergy Shots Build Tolerance in Hours Rather Than Months
But in the current study, Kevin Letz, MD, and colleagues in a private allergy practice in Fort Wayne, Indiana, demonstrate that the rapid allergen vaccination can be performed safely in an office setting with a few precautions.
They also found the "rush" protocol typically saved about six months of build-up time and its associated costs. And because patients experienced relief sooner than they would under a more gradual allergy shot schedule, they tended to stick with the therapy, with nearly 80 percent of patients keeping their appointments at one year.
"In previous studies [of RAV], they found reaction rates of anywhere from 30 to 40 percent, whereas our rate is close to that of conventional immunotherapy [allergy shots]," Letz said in an interview with WebMD.
He attributes the enhanced safety rate to the dosing schedule and to the fact that patients receive both antihistamines and an immune system-dampening drug for three days before receiving the injections.
The study involved 148 children from 1 to 18 years of age who had been diagnosed with nasal allergies and/or mild to severe asthma. The patients received eight injections 15 minutes apart. The shots were given with increasing concentrations of allergy-provoking substances.
Patients were monitored for reactions such as cough or tightness in the throat, and were treated, if necessary, either with an inhaled drug commonly used for asthma control or with an antihistamine pill or injection.
Eight patients (three boys and five girls) had a reaction during the procedure; in each case, the reaction occurred within 15 minutes of the injection, and all patients were successfully treated. All of the patients who had reactions were able to leave the office within two hours, and none required hospitalization. In addition, no patients in the study needed an injection of epinephrine (adrenaline), which is the standard treatment for patients who have the more severe life-threatening anaphylactic reaction.
'Something to Consider,' but Still Has Risks
An allergy specialist who was not involved in the study tells WebMD the rapid allergen vaccination has its advantages, but it isn't for everyone.
"I think so much depends upon your reasons for selecting that method of doing it," Diane E. Schuller, MD, professor of pediatrics and director of allergy and immunology at Penn State University in Hershey, Penn., tells WebMD.
"I have done modified rush immunotherapy, where we bring people up to their maintenance immunotherapy doses within a matter of six weeks rather than six months. They're doing it over a very short period. And for individuals who don't have time to spend to come and participate in the more conservative program, I think it's something to consider, because the ultimate result is that their allergies will be controlled and once you control the allergies you're going to control asthma if it’s present, and you're going to control complications such as sinus trouble or ear problems, and you're going to see a much healthier child."
But Schuller also cautions the procedure has some risks that have to be weighed against potential benefits.
"You're giving something to an individual that they're allergic to, and you're taking a chance by doing it rapidly, that their body is going to respond in the way you want it to. I have talked to parents and they have said to me, 'You know, it would be great to get up to maximum dose in a day or two, but I just couldn't take the risk that my child might have a bad reaction, and I'd much rather do it this way where you have some control over the situation.' "
SOURCES: Kevin Letz, MD, Fort Wayne, Indiana. Diane E. Schuller, MD, Penn State University, Hershey, Penn. American College of Allergy, Asthma & Immunology 2004 Scientific Meeting, Oral abstract 45, presented Nov. 15, 2004.