ANNOUNCER: Allergy is an overreaction of the immune system to normal substances. For many allergy sufferers, the best way to control their symptoms is through immunotherapy.
BETH CORN, MD: Immunotherapy is just a fancy way of saying allergy shots. And allergy shots are a wonderful way to treat allergies, but it involves a time commitment.
ANNOUNCER: Before a regimen of immunotherapy can begin, doctors must first determine what allergies a patient has.
BETH CORN & PATIENT: I'm gonna take these needles, and I'm gonna introduce different proteins from different allergens, and in 20 minutes, we'll know what you're allergic to.
MARJORIE SLANKARD, MD: A person will have skin testing to determine what they're allergic to, and then an extract is prepared that included the things that the person is allergic to. This might for example include tree pollen, something like dust mites, maybe cat dander.
GILLIAN SHEPHERD, MD: Let's say you're allergic to cat. And you're allergic to this amount of cat. Allergy shots mean or allergy vaccine therapy is that you get a shot of the cat, weekly, going up like this once a week until you get up to the top dose. When you get to the top does, the amount you're allergic to-you then switch and you get a shot once a month to keep the allergy turned off. That type of treatment is very effective. What is does is it sort of puts the lid on the over-reactive immune system. Stops it from going crazy every time it sees cat. And as a result, somebody who is on allergy shots to cat, they're allergy system sees cat and just doesn't react.
ANNOUNCER: The length of time that a patient will get allergy shots varies.
GILLIAN SHEPHERD, MD: Most people who do get allergy shots, if they get them for pollens, that they're exposed to, or dust mites on a regular basis, will normally do it for anywhere from three to five years. It's not a forever treatment. It is a forever treatment for the cat owners as long as they own the cat.
ANNOUNCER: Many allergy sufferers are good candidates for immunotherapy.
MARJORIE SLANKARD, MD: The candidates for immunotherapy would be someone with allergic rhinitis and or allergic conjunctivitis or allergic asthma who, is not doing ideally with trying to control their environment in some limited medications.
ANNOUNCER: But there are some allergy sufferers who should not receive allergy shots.
BETH CORN, MD: Very severe asthmatics would probably not be candidates for allergy shots. The most common side effect is a local reaction to the allergy shot. So if someone receives an allergy shot in their arm, chances are that if they're going to have a reaction they might get a red raised reaction.
MARJORIE SLANKARD, MD: There are certain patients who may have cardiovascular disease, who are on a medication like a beta blocker or who have some other general, severe systemic illness where we may not recommend that they go on a program of allergy shots.
GILLIAN SHEPHERD, MD: We generally don't give them if the patient is very elderly. They may be managed by medication. The only hesitation in some physicians is to not give them to patients who have something really wrong with their immune system, certain diseases. There's actually no evidence that allergy shots cause any problem with the immune system, but there sometimes is hesitancy about that.
ANNOUNCER: One thing to remember about allergy shots is that they are very specifically targeted treatments.
GILLIAN SHEPHERD, MD: If you get allergy shots for cat, the mechanism of giving you the injections on a regular basis is settling down your immune system but only for it's over-reactivity to cat. It doesn't affect any other part of the immune system. The treatment is very safe; it's been done for more than 50 years now and granted the materials are always tuned up and changing a little bit. But as far as its effect, it's extremely safe.
ANNOUNCER: Throughout much of the world, allergies and asthma are on the rise. Within the medical community, there are several theories about why this is happening.
MARJORIE SLANKARD, MD: One of these is due to, we think, diesel fuel. Another may be that we live in a more sterile environment.
GILLIAN SHEPHERD, MD: It's called the so-called hygiene hypothesis. Which means we live in too-clean an environment. And what it turns out is that at one point in the immune system, which is this giant roadmap, there's a Y fork in the road. And one fork in the immune system goes off to fight infections. And if it's not busy off fighting infections, it defaults automatically to this fork. This fork has a lot of functions, but one of it is to go and produce allergies. Now if this fork is off fighting infections-nowadays we're bringing up our kids in a clean world. They get fewer diseases, they're vaccinated for a lot of things, we have antibiotics. So it turns out this fork of the immune system is not getting stimulated as much as it used to. And therefore it seems to default over to this side, which makes allergies.
BETH CORN, MD: I think the biggest theory is recognition. So what might have been termed a severe cold twenty years ago that lingered, is now attributed to allergies. What might have been termed bronchitis, is now termed asthma.
ANNOUNCER: With a growing awareness of allergy all over the world, allergy sufferers can now find an effective treatment regimen to keep their symptoms under control.