Board-certified allergists at New York Presbyterian Medical Center are involved in the evaluation and treatment of chronic asthma, allergic and non-allergic rhinitis, atopic dermatitis, drug allergy, food allergy, anaphylaxis, and sinusitis.
Patients are often evaluated using a multi-disciplinary approach in conjunction with pulmonologists, allergists and nurse educators. Specialists such as otolaryngologists (Ear Nose and Throat), dermatologists, social workers, and Visiting Nurse Services are also available, During an evaluation, a complete allergy and environmental history is obtained. When indicated, a comprehensive panel of skin and blood testing to foods, dogs, and allergens is applied and interpreted and various types of pulmonary function testing are performed.
Clinical Research at the Center focus on the early detection of allergic diseases and the development of new approaches for the effective treatment of these diseases.
Allergic reactions occur when the immune system mistakenly learns to remember innocent foreign substances as potentially harmful. Such substances are called allergens. Pollens, mold spores, house dust mites, animal danders and foods are among the allergens that most frequently cause problems.
Not every adverse reaction to something in the environment is an allergy. Problems caused by toxins, irritants or intolerance are not necessarily due to allergies.
An antibody called immunoglobulin E (IgE) plays an important role in allergic reactions. Antibodies are produced by a class of white blood cells known as B cells, which in turn are regulated by another key group of blood cells called T cells.
Allergic reactions develop when an individual is sensitized after his or her initial exposure to an allergen. The immune system overreacts to the allergen by producing an excessive number of IgE antibodies directed against that allergen. These IgE molecules, bound to their specific antigen, then attach to cells called mast cells, which reside in the nasal passages and upper respiratory tract. These mast cells, when activated by the bound IgE molecules, release strong chemicals which elicit inflammation. The best known of these chemicals released by mast cells is histamine. After this sensitization process, when the allergen is inhaled again, it binds to it's specific antibodies on the mast cell. The mast cells then release their mediators into the nasal passages and/or airways, causing blood vessels to swell and mucus glands to secrete mucus.
Runny and itchy nose caused by exposure to allergens is called allergic rhinitis, though many people use the old term "hay fever.". Other upper airway symptoms of allergies include sneezing, sniffling, stuffy head and red, watery eyes that are hallmarks of this common allergic condition.
The symptoms of allergy aren’t limited to the nose and eyes. Other organs can be affected - especially the skin, the lungs, the digestive tract and the blood vessels.
The skin conditions most often associated with allergy are urticaria and eczema. Urticaria - sometimes called hives - is the appearance of itchy red swollen areas of the skin, usually soon after exposure to an allergen. The hives may be small bumps or large irregularly shaped areas.
Eczema, also know as atopic dermatitis, is a dry, scaly skin rash that causes intense itching. The skin may even crack and bleed, or become infected. Symptoms may last for months at a time, clear up, and then return.
Not all asthmatics have allergies, but those who do can experience asthma symptoms after exposure to an allergen. Doctors call this extrinsic asthma - asthma brought on by something from outside the body. It is not uncommon for exposure to the allergen to result in both allergic rhinitis AND asthma symptoms, since both the upper and lower airways contain mast cells which are sensitive to the specific allergen.
Allergy can occassionally cause abdominal cramps, nausea, vomiting or diarrhea. These symptoms are most common with food allergy, but can occur with other types of allergy as well.
Anaphylaxis is the most serious kind of allergic reaction. Fortunately, it’s rare. Most people with allergies never experience an anaphylactic reaction. Symptoms usually appear rapidly - within seconds or minutes - after exposure to an allergen, but in a few cases, reactions have been delayed as much as 12 hours.
In anaphylaxis, cells in the immune system release large amounts of chemicals - including histamine. As a result, blood vessels dilate and begin to leak fluid into surrounding tissues, producing swelling. Leaking of fluids outside of the blood vessels can cause a sudden drop in blood pressure. Symptoms, which usually appear rapidly, can include hives, itching, light-headedness, vomiting, diarrhea and severe breathing difficulty. Individuals with a history of anaphylaxis should talk to their physicians about preventative measures and in some instances, medications to have on hand.
The diagnosis of allergy begins with careful questioning to determine whether symptoms appear when the patient is at a particular location, or at a given time of day, day of the week, or season of the year. Questions related to work, household and leisure activities may help define the allergens to be avoided. Once specific allergens are identified, further testing can be done for confirmation. These tests are described on the Allergy Testing Page.
