What is Allergy?

1. What is Allergy? Robert Grimshaw MD FACP A Lifetime of Quality Care That’s Convenient & Complete

2. What is Allergy? In 1902, two French Scientists injected dogs with an extract of the sea anemone. Nothing happened. When they repeated the injections a week later, the dogs developed severe reactions to the extract – becoming "sensitized". That was the start of our understanding of the allergic response. Antibodies are formed against antigens, or allergens - the proteins we know as mold, pollens, house dust mites, animal danders and foods. The antibodies involved in allergy are usually a special class called IgE - Immunoglobulin E. These chemicals act as the "key" to open a "lock" in the surface of special immune cells, called mast cells. These cells contain granules of various inflammation proteins, including histamine, that cause the symptoms of runny nose, watery eyes, itching and sneezing.

4. What Can You Do? First, you can avoid the allergens! That means avoiding feather pillows, carpets or rugs (which hold dust mites), keeping animals out of bedrooms and staying away from suspect foods and allergy triggers. Second, allergy shots can help! They induce a different antibody class, IgG, in the blood. As this antibody, circulates, it "scoops up" the allergen before the IgE "sees it." So, no binding, no harm, no foul. Third, antihistamines help. The newer ones (Allegra, Claritin, Clarinex, Zyrtec) have less side effects than older drugs. And there are topical agents such as Patanol, Livostin (for the eye) and Astelin (for the nose). Fourth, anti-inflammatory medications may help. These include cromolyn (Nasacrom, Opticrom, Intal) and nedocromil (Tilade), and Alamast (for eyes) which are also mast cell stabilizers; the non-steroidal medications  Zaditor and Acular (for eyes), and leukotriene inhibitors Singulair and Accolate. Fifth, corticosteroids are the ultimate anti-inflammatory drugs. These include prednisone, methyl-prednisolone (Medrol, etc), and dexamethasone (Decadron, etc.) by mouth; various inhalers for the lung (Aerobid, Azmacort, Beclovent, Flovent, Pulmicort, Vanceril, etc.), and for the nose (Beconase, Flonase, Nasacort, Nasonex, Nasalide, Nasarel, Rhinocort, Vancenase, etc.)

5. The Future? Xolair on the Horizon Omalizumab (Xolair) is a recombinant, humanized monoclonal anti-IgE antibody. A study in the Journal of the American Medical Association found that the drug decreased levels of IgE in the blood and reduced symptoms in patients with runny noses from ragweed or pollen. Those on Xolair missed work or school 75% less than those on placebo. In another study, the drug also reduced the need for steroids in asthmatics. There are drawbacks - the drug is given as an injection every 3 weeks throughout the allergy season. The FDA approved the drug for asthma in 2003 for patients over 12 years of age. Severe anaphylactic allergic reactions to Xolair have been reported.