MedicineNet.com
About Us | Privacy Policy | Site Map
February 9, 2010
MedicineNet home Picture Slideshows Diseases and conditions Symptoms and signs Procedures and tests Medications Picture Image Collection MedTerms medical dictionary Pet Health
Font Size
A
A
A


Allergy/Allergies

Medical Author: Alan Szeftel, MD, FCCP
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

Introduction

In this review you will learn how allergy relates to the immune system. You will begin understanding how and why certain people become allergic. The most common allergic diseases are discussed briefly in this article.

Doctor to Patient

Air Pollution and Allergies: A Connection?

Medical Author: Alan Szeftel, MD, FCCP
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

Is there a link between allergies and air pollution?Does the "air we breathe" have an impact on the rising incidence of allergies and asthma? Hay fever was rare in Japan before World War II. However, pollen allergy is now common and mostly affects those living in Japanese cities and near highways. Allergic disease is also more common in highly developed countries in North America and Europe and less common in Third World countries. This suggests that there must be something about modern, urban life that promotes allergy. Let us examine the impact of air pollution.

By far the most important indoor pollutant is tobacco smoke, which is strongly associated with allergic sensitization, asthma, and other respiratory illnesses. Exposure to smoke results in the body's enhanced ability to produce IgE (the allergy antibody) that attaches to allergens (e.g. pollen, dust mites and dander). The IgE response is a key trigger of allergic reactions. Parental smoking increases the risk of their children having many respiratory illnesses, including bronchitis, chronic cough, and asthma. Smoking during pregnancy and breastfeeding results in a higher risk for the children to develop allergic eczema (atopic dermatitis).


Doctor to Patient

What does an allergy mean?

An allergy refers to an exaggerated reaction by our immune system in response to bodily contact with certain foreign substances. It is exaggerated because these foreign substances are usually seen by the body as harmless and no response occurs in non- allergic people. Allergic people's bodies recognize the foreign substance and one part of the immune system is turned on. Allergy-producing substances are called "allergens." Examples of allergens include pollens, dust mite, molds, danders, and foods. To understand the language of allergy it is important to remember that allergens are substances that are foreign to the body and can cause an allergic reaction in certain people.

When an allergen comes in contact with the body, it causes the immune system to develop an allergic reaction in persons who are allergic to it. When you inappropriately react to allergens that are normally harmless to other people, you are having an allergic reaction and can be referred to as allergic or atopic. Therefore, people who are prone to allergies are said to be allergic or "atopic."

Austrian pediatrician Clemens Pirquet (1874-1929) first used the term allergy. He referred to both immunity that was beneficial and to the harmful hypersensitivity as "allergy." The word allergy is derived from the Greek words "allos," meaning different or changed and "ergos," meaning work or action. Allergy roughly refers to an "altered reaction." The word allergy was first used in 1905 to describe the adverse reactions of children who were given repeated shots of horse serum to fight infection. The following year, the term allergy was proposed to explain this unexpected "changed reactivity."

Allergy Fact
  • It is estimated that 50 million North Americans are affected by allergic conditions.
  • The cost of allergies in the United States is more than $10 billion dollars yearly.
  • Allergic rhinitis (nasal allergies) affects about 35 million Americans, 6 million of whom are children.
  • Asthma affects 15 million Americans, 5 million of whom are children.
  • The number of cases of asthma has doubled over the last 20 years.


Next: What causes allergies? »

Allergies - Describe Your Experience

The MedicineNet physician editors ask:

Please describe your experience with allergies.

Comment submissions for this question have ended. Patient Discussions FAQs
See 20 Viewer Comments

View Comments


Printer-Friendly Format  |  Email to a Friend


Suggested Reading by Our Doctors
MedicineNet Doctors
  • hydroxyzine, Vistaril, Atarax - Specifies the medication hydroxyzine (Vistaril, Atarax), a drug used for the relief of nasal and non-nasal symptoms of various allergic conditions such as seasonal allergic rhinitis.
  • Cortisone Injection - Read about cortisone injection treatment for inflammation, allergic reaction, sciatica and arthritis. Learn about side effects and complications of a cortisone shot.
  • Eczema - Get information about eczema causes, skin symptoms, diagnosis and treatment. Types include dyshidrotic, atopic dermatitis, nummular, varicose and seborrheic eczema.

Latest Medical News


Allergies & Asthma

Improve treatments & prevent attacks.


Are you Depressed? Take the Quiz

Your Guide to Symptoms & Signs: Pinpoint Your Pain



Allergy

What can I do to keep insects away?

  • Use structural barriers such as window screens and netting.
  • Avoid wooded, brushy, and grassy areas when possible.
  • Don't wear heavily scented soaps and perfumes.
  • Use caution eating outside and drinking; don't leave drinks and garbage cans uncovered.
  • Don't wear bright colors, which attract bees.
  • Wear long sleeves and long pants when possible.
  • Tuck pant legs into socks or shoes.
  • Wear a hat for extra protection.
  • Get rid of containers with standing water that give mosquitoes a breeding ground. Examples include water in flowerpots and outdoor pet dishes.
  • Use insect repellent if nonchemical methods are ineffective and you spend time in tall grass and woody areas.
  • Treat camping gear, clothes, and shoes with permethrin, which repels and kills ticks, mosquitoes, and other insects. Clothing that is pre-treated with permethrin is also c...

Read the Bug Bites and Stings article »











Health categories:

Slideshows | Diseases & Conditions | Symptoms & Signs | Procedures & Tests | Medications | Image Collection | Medical Dictionary | Pet Health

Popular health centers:

Allergies | Arthritis | Blood Pressure | Cancer | Chronic Pain | Cold & Flu | Diabetes | Digestion | Eyesight | Health & Living | Healthy Kids

Hearing & Ear | Heart | Infectious Disease | Men's Health | Mental Health | News & Views | Pregnancy | Sexual Health | Skin | Women's Health | More...

MedicineNet.com:

About Us | Newsletters | RSS Feeds | Privacy Policy | Site Map | WebMD® | Medscape® | eMedicine® | eMedicineHealth® | RxList®

This website is certified by Health On the Net Foundation. Click to verify. This site complies to the HONcode standard for trustworthy health information:
verify here.

©1996-2010 MedicineNet, Inc. All rights reserved. Notices and Legal Disclaimer.
MedicineNet does not provide medical advice, diagnosis or treatment. See additional information.