Wednesday, March 28, 2012

Your Allergy Treatment Options

When your allergy or allergies have been diagnosed, the allergy specialist will try to identify which body systems are involved and how severe are the allergies. An individual may have a mono (single) or multiple allergies, involving different organs in our body. Classically, allergy involves a few organ systems (Table 1).

Allergy Avoidance
Once the offending allergens have been identified, the easier way to 'cure' your allergies would be to avoid the allergen. It is often easier said than done but a little effort in cleaning your home or office by wet mop or water based vacuum cleaner goes a long way in reducing respiratory symptoms such as sneeze, runny nose and even asthma. Frequent housekeeping and clearing of rooms of unused furniture reduce the deposition of house dust mites (HDM) and pet fur. However, the largest collection of HDM can be found within the mattress and pillows that we sleep on every night. Vacuuming beddings have shown to have some degree of improvement for asthmatics, it is indeed a laborious task and many parents usually abandon this rigorous task in the long run. Changing bedsheets and pillow covers have usually minimal effect since the HDM resides deep within the mattress.

It is interesting to note that HDM allergy is not provoked by the mite per se but rather its droppings which are few microns in size. The droppings therefore can easily pass through the woven fabric of beed and pillow covers and float freely in the air. Fans and closed windows help circulate these droppings within the bedroom atmosphere. Another common items HDM breed are soft toys, often hugged by the sleeping child. It is recommended to clear bedrooms of all fabric toys and pets. Windows should be opened for ventilation. Soft toys should be frequently washed and throughly dried in direct sunlight for more than 4 hours. Some doctors advocate the use of eucalyptus oil and detergent to presoak the toys for a few hours prior to wash.

The use of HDM proof beddings is gaining popularity. Indeed some mattress manufacturers incorporate "anti dust mite " features built in . What this essentially means that the mattress fabric is usually infused with acaricides (Anti HDM) chemicals that kill the HDM on contact. While this may sound good, be aware that there have not be any large studies detailing the effects of these chemicals on the human body. There are however newer Anti dust mite sheets that are chemical free and relies on high tech weaving that prevents the free movement of mites or droppings from the mattress to the surface.

Next: A look at medications.






Table 1: Common Allergies and the organs involved

: Organs involved

Symptoms

Allergic Disease

Respiratory:

Nose

Lungs

Itchy, runny and blocked nose,

Watery Nose and sneezing.

Chest tightness, shortness of breath,

Wheezing, Dry cough.


Rhinitis, hypertrophied

Nasal Turbinate

Deviated nasal

Septum.

Asthma, chronic dry

Cough.

Allergic Bronchitis

Skin

Itch, Rash, Skin Swelling.

Urticaria, eczema,

pruritic
rash

Digestive System

Lip/tongue numbness and swelling,

Diarrhea, Vomiting and sensitive

Stomach.

Angioedema

Eyes

Red Eyes, Eyelid swelling, Watery

Eyes.

Allergic conjunctivitis

Friday, March 16, 2012





If you believe you have allergies, it makes sense to find out what your allergies are. Locating a doctor who specializes in allergy (Allergist) in Malaysia is not an easy task as there are only a handful doctors who offer the service.




Allergy tests today are more convenient and accurate than before. Before we go into the various tests available, its important to understand these two terms:


Sensitized: means your body is 'primed' to an allergen. A positive skin test therefore indicates that you are sensitized to the allergen while you may not necessarily have the allergic symptoms. Confused? This means that you may test positive for peanuts by allergy test; although you have never developed any allergic symptoms to peanut before. In another words, sensization to peanuts means you have the potential to develop peanut allergy in the future, even if you never had peanut allergy. More confused? Read on and I will explain.


Allergy: means definite reaction to allergen. This means when the doctor says you are allergic to peanuts (as an example), eating peanuts will surely provoke allergic symptoms (itchy rash, puffy face and eyes or choking).

The interpretation of allergy test to identify the offending allergen is best left to allergist or doctors trained in allergy - to avoid any misinformation. An allergist is trained to distinguish between a sensitization and a true allergy by taking a careful allergy history and interpreting the allergy test. In addition, the allergist is to treat a person with multiple allergies involving different organs. A patient may be suffering from skin, dust and food allergies at the same time and it is important to identify and treat all the allergies simultaneously.

Now, lets talk about the different allergy tests.

Allergy testing involve skin and/or blood test to identify allergens that is causing your allergy. Allergy test can be broadly classified into two groups, namely Skin Prick Test and Blood Test.


Skin Prick Test

Skin Prick Tests (SPT) can be done as an outpatient procedure in an allergy alinic. This is the most preferred test method as the results can be known in 15 to 20 minutes and its cheaper than blood tests.

The SPT comes in a kit form with small bottles of laboratory prepared allergens. The doctor selects the allergens to be tested (usually up to 10 allergens ) and apply a very tiny drop of the allergen on your forearm. The doctor then makes a tiny needle prick on the skin surface through the applied allergen drop (don't be afraid-it does not hurt as the needle rest only on the skin surface). There is usually no blood seen during the test.
Each suspected allergen is tested by individual pricks. Usually up 10 allergens can be tested on a single sitting. A small swell at the site of the needle prick ( more than 3mm diameter) within 15 minutes is said to be a positive test for that allergen. (image below).

Remember: These tests only denotes sensitization and not necessarily allergy.

Another modified skin prick test is called the prick-prick test which is usually done for fresh food or fruits. A small slice of the food is pricked with the needle before pricking onto the skin. A swelling at the site may indicate allergy to the said fruit.

Blood Test : The Rast or Immunoabsorbant assay
This test involves drawing blood from the forearm and dispatching it to labs that do allergy testing. After a couple of days , the results will indicate the level of antibody for the tested allergens. The allergen specific antibody called IgE (Immunonoglobulin) will be raised if your are sensitive to the allergen. Again, this is a sensitization test- a high level IgE is indicative of sensitization but not necessarily allergic to the allergen.

Patch Test
Patch test is usually done to detect contact dermatitis. This includes testing for metal, chemical, leather and latex allergies.There are a few types of test kits available in the market. It comes with a standard of 10-20 common pre-filled metals, chemicals and other materials that commonly causes skin allergies such as eczemas and dermatitis. These are then applied to the back of the torso and left for 24-48 hours before reading for reactions. The stronger the reaction the more pronounced is the redness. Sometimes, the reactions can be so strong that it causes a bleb or a wound at the site. The patient is usually warned to remove the patch if there is pain.

The type or the quantity of test selected by the allergist is dependent on the disease; based on a good clinical history and medical examination. A consent is a must before any test can be performed.

Next chapter: What are your treatment options?












Thursday, March 15, 2012

Allergy- Lets Start from the Beginning!















Why do some people get allergy while others don't? Well, simply, people with allergies have a confused immune system!

You see, our immune system is designed to protect us from the many thousands of harmful bacteria, virus, fungi and even chemicals. The main defensive army of our immune system are the white blood cells (WBC). Like soldiers, there are many varieties - army,navy, air force etc., the WBC varieties include the the neutrophils, lymphocytes, eosinophils, monocytes and platlets. Without going into details, suffice to say their job is to defend our body against infection around the clock 24/7/365.

The WBC are able to identify and distinguish between a friendly cell (such as our own organ cells called self cells and an enemy cell such as bacteria and viruses called non-self cells). Not all of the invading cells are harmful; indeed a large percentage of these non-self cells are harmless bystanders that neither help nor harm our body. Examples of these 'innocent bystanders' include what we call as allergens such as dust mite droppings, animal furs and tree pollen inhaled when we go about our daily activities.

The confused WBCs attack these 'innocent bystanders' thinking that they are bacteria or viruses. And hence, an allergic reaction produce similar effects of a common flu such as nose itch, sneeze and runny nose. The eyes are often involved too, with red watery discharge.

It's believed that similar responses occurs within the skin causing contact dermatitis and in the lungs as in asthma. Over time, research into immune system revealed the highly complex pathways that allergy develop, i.e. right from the time of contact with the allergens to the development of symptoms. In fact, new research shows there may be many other complex pathways and chemicals involved in forming allergies of other systems, such as food and eczemas.

To develop allergies, one needs to have the allergy genes within their DNA. However, possessing the allergic genes alone does not confer one to suffer allergies. Exposure to allergens is a vital ingredient to developing allergy. Prolonged exposure to allergens (months or even years) may be necessary to provoke an allergic response. This may be the reason why many patients find it hard to believe the house they lived in or their pet FiFi is a source of their rhinitis or asthma!

I hope this sheds some simplistic light into the basic mechanism of allergy. I must admit, it has been a challenge and a learning experience for me to simplify the immune mechanism of allergy.

Up next: How do we find out if we have allergies