What is an allergy?

An allergy is a misguided, abnormal autoimmune response caused by foreign objects that are usually harmless to people. An allergy inducing object is called “allergen”. Allergies consist of a wide range of symptoms and affect people differently. It can also run in families. Most allergic reactions include the eyes, nose, skin, lungs and stomach. The level of severity also varies with the type of allergens, level of exposure and the individual’s age and immune system.

Some important fact about Allergy

• It affects more than 50 million people in the United States
• Medical expenses for allergy cost the nation more than $15 billion yearly.
• Asthma affects 1 in every 15 children in the United States 1
• Allergic rhinitis causes more than 16
million doctor’s office visits each year.
• Many severe food induced allergic reactions are caused by peanuts and tree nuts.
• Penicillin allergy cause more death than food allergy and about 400 people die from penicillin allergy every year
• Between 10 to 20 percent of the US population are affected by hives at some point in their lives.

Sources: National Institute of Allergy and Infectious Diseases

How does a person develop an allergy?

In the human body, white blood cells are responsible for guarding our bodies against the intrusion of foreign objects such as bacteria, viruses and toxic substances. The main type of white blood cells which initiate defense mechanism is called lymphocyte, namely B-cells and T-cells. These cells patrol around the body to find out any suspicious foreign objects. Not all foreign objects are capable of triggering allergic reaction. Only those the lymphocytes recognize as threats to the body can trigger reactions by the white blood cells. When the B-cell identifies a threat, the body will produce immunoglobulin E (IgE) to work against the threat. The B-cells of an allergic person regard the harmless foreign object as life-threatening, causing large quantities of IgE to bind to the mast cells and basophils. The IgE bound mast cells and basophils then become capable of recognizing the allergen. This first exposure to allergen is called “sensitization”.

The actual killers of the foreign object are the mast cells and basophils which act as the bodyguards of the human bodies. The mast cells and basophils both contain large amount of histamine. When the same allergen happens to come into contact with the body again, the IgE bound mast cells and basophils then start to release substantial amount of histamine into the tissue and the blood, leading to vasodilation and lower blood pressure. Body fluids are also increased between spacing cells. The action of releasing histamine brings about many common allergic reactions such as: itching of the body, eyes, or nose, hives, sneezing, wheezing, diarrhea, nausea, and vomiting, hoarse voice and dizziness. Severe reactions can be low blood pressure, shortness of breath, unconsciousness or even cardiac arrest. Depending on the site of allergy, symptoms may vary.

A person can have a reaction to a variety of allergens. The types of allergies are generally divided into five categories:

• Food allergy: most common allergens are dairy products, eggs, peanuts, strawberries, fish, shellfish and cereals, etc.
• Inhalant allergy: grass pollen (eg. foxtail grasses), tree pollen, mold spores, dust mites and animal dander, etc.
• Insect allergy: ants (eg. fire ants), wasps, hornets, honey bees, yellow jackets.
• Drugs: penicillin, codeine, aspirin, etc.
• Chemical allergy: Nickel is one of the most typical metals that elicit allergic reactions.

According to a research, about 10% of all women are sensitive to nickel. Some cosmetic products and topical drugs containing lanolin also cause allergic reactions to some people. Other common chemical allergens include but not limit to neomycin (found in topical drugs), potassium dichromate (in wet cement, chrome tanned leather), fragrance (in perfumes & toiletry products) and latex etc.

Classical allergic diseases include hay fever, perennial allergic rhinitis, asthma, eczema, and hives etc. A sudden, severe, fatal allergic reaction is called anaphylaxis anaphylactic shock.

An allergy can be as bad as poison. A British woman who was tomatoes allergic died accidentally as a result of her son’s opening a can of tomatoes next to her. Although this is a rather extreme case, precaution should never be ignored. For most of the people, allergies are a mild and seasonal problem that over the counter medication is enough to help. At most, people may need to see their doctors for prescriptions. However, if someone is having a tough allergy that recurs all year around and interferes with the daily life at work or school, it is necessary to consult an allergist. An allergist can diagnose, give advice and help improve the quality of life of the patient, especially the one suffering from life-threatening allergic problem.

Following is a checklist for you to choose a suitable allergist:

1. Seek your primary doctor's advice before going to find an allergist.
   
   
2. Find an allergist who is certified by the American Board of Allergy and Immunology. A board certified allergist is more reliable and generally has the latest knowledge and techniques.
   
   
3. Find an allergist with a background that fits your needs. For example, a child with an allergy should find an allergist with pediatric background.
   
   
4. Find an allergist who is able to fully communicate with you, understand and listen to your problem.
   
   
5. Find an allergist who will discuss your possible choices of treatments, explain their pros and cons, give you advice and adhere to your decision.
   
   
6. Find an in-network allergist so that your medical expenses can be covered by your insurance as much as possible.Ask your relatives or friends if they know any good allergist.

Treatment for allergiesThree options of treatment for allergies can be sought: (1) avoidance of the allergens (2) medications, e.g antihistamines, decongestants, and corticosteroids etc. (3) immunotherapy. We most likely have certain understanding of the first two options. Now, we will go on and have a brief discussion about the third option – immunotherapy.

As given by its name, immunotherapy has something to do with our immune system. The concept of immunotherapy is to use the body's own defense system to fight against the allergens. Immunotherapy involves a series of shots that contain very small amount of the allergen you are allergic to. Each time the patient receives a shot, his or her own body will create antibody against that allergen. A stronger and stronger resistance against the allergen is build up over time. The patient will then become less allergic to that allergen.

However, immunotherapy is not given to everyone. Only when the doctor is very sure that the allergy is exactly caused by the known allergen. Immunotherapy is relatively expensive and it takes time to get the job done. Although it is generally safe, there are still risks. Adverse reaction i.e. anaphylaxis requires immediate treatment.

Allergy Myths

#1: Milk allergy is EQUAL TO Lactose Intolerance.
This is NOT TRUE.
Then…..what is Milk Allergy?
Milk allergy is an abnormal immune reaction to the proteins found in cow’s milk while lactose intolerance is the inability to digest sugars found in milk. Symptoms of lactose intolerance include swollen abdomen, stomach pain, excessive gas, and diarrhea.

Although cow’s milk allergy can happen in any time of the life, it is most prevalent in infants (between 1% and 7.5% of infants are allergic to cow’s milk and cow’s milk-based formulas). The onset of the allergy usually appears within the first half year for infants and the majority of the children who suffer milk allergy will outgrow the allergy by the age of 2. Infants with milk allergy may fail to thrive (difficulty in gaining weight and growing normally) if not treated properly.

Milk allergy can affect several body systems including integrumentary (skin), gastrointestinal (from the stomach to the intestines), and respiratory systems. The symptoms of milk allergy are listed as below:

Integrumentary: itchiness, hives, rash, eczema, swollen lips, tongue, face, mouth or throat, dark circles around the eyes.Gastrointestinal: bloating, vomiting, gas, abdominal pain, diarrhea, stool with blood.

Respiratory: watery or itchy eyes, runny nose, sneezing, coughing, wheezing and shortness of breathMilk allergy can be severe. Acute reactions can lead to life-threatening respiratory depression if not treated properly. Myth #2: Insect sting can be FATAL. Insects like to sting on surface with dark colors.

This is TRUE.

According to Jean A. Chapman, M.D. of the American College of Allergy, Asthma & Immunology (ACAAI), there are more than 500,000 emergency room visits every year because of insect stings. Over 2 million Americans are allergic to stinging insects. Although most allergic reactions of insect stings are mild, there are still cases reporting death resulted from severe allergic reactions due to insect stings.

Types of reactions:
Insect bites or stings can be divided into three types of reaction: normal, toxic and an allergic reaction.

A normal reaction after an insect bite usually involves redness, swelling, itching, and warmth of the skin at the site of the bite. The symptoms normally last no more than a few hours. A person with multiple stings may develop muscle cramps, headache, fever, and drowsiness as a result of the toxic reaction. These reactions may last for several days. An allergic reaction is similar to a toxic reaction, but is usually caused by one sting.

Prevention Tips

The American College of Allergy, Asthma and Immunology recommends the following precautions to avoid stings from bees, wasps, hornets, and yellow jackets.

1. Since honeybees and bumblebees like to forage on white clover, avoid walking barefoot in the grass.
   
   
2. Remember, insect repellents DO NOT work against stinging insects.
   
   
3. Do not swat or flap at a flying insect. It is better to wait until it leaves or gently brush it aside.
   
   
4. Do keep your food and beverage covered at all times when eating outdoors because stinging insects also like the food and the sweet beverages that you have.
   
   
5. Garbage cans with tight-fitting lids should be used.
   
   
6. Perfumes, hairsprays, colognes or deodorants with sweet scents should be avoided when going outdoors.
   
   
7. Stinging insects are attracted to floral patterns and bright colors, so try to wear clothing with light colors.
   
8. A person who is allergic to insect sting has 60% chance of having the same, similar or worse reaction if stung again. The best choice is go to see an allergist who can provide proper treatment.

Myth #3: A person who never approaches a cat may still suffer from allergic reactions.

This is TRUE..

According to a report from HealthDayNews, almost 100% of the homes in the United States contain dog and cat allergens although only half of the homes actually have pets. As a matter of fact, many pet allergens are brought in the houses on clothing. Even though a home does not own any pets, pet allergens can be already present from a previous pet owner. Animal danders are so small that they can stay airborne for several months. For example, Fel d 1 is a very common cat allergen which is a glycoprotein secreted by the cat’s sebaceous gland. This type of allergen is 10 times smaller than dust particles or pollens. It can be found in almost any part of a cat, especially in the cat’s skin and saliva. Public places such as hospitals, supermarkets, restaurants, schools, and malls are also the sources of dog and cat allergens.

The symptoms of an animal allergic reaction are similar to the conditions of other allergies. Still, reactions vary with people. Therefore, medical attention should be sought once serious symptoms develop.

Prevention Tips

1. Change carpet floor to tile floor
2. Remove all the stuffed toys
3. No more pets in the house
4. Keep an air filter in your house
5. Wash all bedding regularly
6. Vapor-clean your carpet
7. Vacuum carpet twice a week

Myth #4: Young children can grow out of asthma.
This is Not NECESSARILY TRUE.Many symptoms of allergic diseases seem to disappear as children grow up as a consequence of a more mature immune system. For example, young children frequently outgrow hay fever, eczema and asthma by their teens. However, the disappearance of symptoms does not necessarily mean the underlying diseases have disappeared, particularly in the case of asthma.

What is asthma?

Asthma is a chronic respiratory disease that affects millions of Americans. Unfortunately, half of the affected population is children. Spasm, inflammation, and over-reacting of the bronchi can trigger narrowing of the air way, leading to an asthma attack which causes coughing, wheezing, mucus production, tightness of the chest and shortness of breath.

The onset of asthma usually occurs during childhood. Moreover, asthma cannot be cured. People who shake off the symptoms of asthma may have it again later in their lives. In fact, it can occur at any time in their lives. Therefore, proper and continuous attentions to the respiratory system are particularly important for people with asthma history. Although there is no cure for the disease yet, asthma can be controlled through medical treatment and avoidance of the potential allergens. Typical asthma treatments include anti-inflammatories to reduce the swelling of the airways and bronchodilators to relax the surrounding muscles of the bronchial tubes. Examples of anti-inflammatory and bronchodilating medications include prednisone and albuterol respectively.

Prevention Tips

Followings are some of the most common asthma allergens. It is recommended people having asthma history should keep these irritants away from their homes and workplaces as far as possible.

1. Dust mites
2. Mold
3. Ets
4. Pollen
5. Smoke ( especially cigarette )
6. Cockroaches

Reference:
The Bible Cure for Allergies, Don Colbert, M.D., Allergies: What you need to know, Johns Hopkins HealthThe Allergy Bible, Linda Gamlin