Once specific allergens have been identified, the patient must attempt to avoid these substances and clear them from the home and workplace as much as possible. A natural extension of the identification of allergy is the consideration of desensitization or immunotherapy by an allergy specialist. Allergy “shots” are given after sensitivity to specific allergens has been identified. These injections contain extremely small amounts of the allergen which is slowly increased in amount. These injections produce a “blocking antibody” that interrupts the allergy reaction. Studies of immunotherapy in asthmatics have shown a reduction in symptoms and inhibition of the late asthmatic response. The administration of immunotherapy is a gradual process, often requiring weeks or months to achieve a response. In older subjects the response to treatment may not be as pronounced as in younger patients. Extremely sensitive patients may experience generalized allergic reactions to the administration of allergens.
Recent studies have focused on fatal reactions to allergy injections. The majority of these cases were patients with severe asthma who had histories of severe asthmatic attacks that required steroids and hospitalization. These patients also appeared to be highly sensitive individuals who may have had a previous reaction to allergen injection.
Who Should Be Treated?
In patients with mild or moderate asthma who are well controlled on medication, allergy injections or immunotherapy should not be necessary. Those patients who are unstable should be considered candidates for treatment. In those allergic patients whose symptoms are more severe or who require frequent or continuous administration of corticosteroids the potential benefits of immunotherapy should be weighed against the potential for severe reactions. Once a response to immunotherapy is obtained the patient may remain on maintenance therapy for several years.