1. What does the word “allergy” mean?
Allergy is a hypersensitive disorder of immune system. An allergy occurs when the body overreacts to an allergen or ‘trigger’ that is typically harmless to most people.The word allergy is not prejudiced with regard to its causes. So, allergy type reactions can be induced by either immune mechanisms (too much allergy antibody IgE) or by a direct hypersensitivity to an irritating fume, vapor or medication (as occurs with codeine and strong perfumes).
2. What causes allergy?
Allergic reactions are caused by the interaction of a person’s immune system with the outside world. Foreign proteins especially small proteins from pollens, molds and dust mites can cause an immune reaction in an individual. If the immune reaction induced by these foreign proteins, otherwise referred to as allergens, involves IgE antibodies, then the possibility exists for an allergic reaction to occur. Any substance which is able to induce a person to make an allergy antibody type of immune reaction is referred to as an allergen.
3. What are the most common allergens?
The most common causes of allergy and asthma symptoms are allergens derived from pollens, molds, house dust mites, animal danders and insects. Many people also experience symptoms of allergy due to altered reactions to foods and medications.
4. How are allergies diagnosed?
The diagnosis of an allergy disease is made on the basis of a detailed medical history and physical examination usually by a certified allergy/immunology specialist. Most often, this will also involve a number of allergy skin tests which are used to detect the real causes of the allergic reactions and consequent symptoms.
5. Can allergies be diagnosed by a blood test?
The diagnosis of an allergic disease cannot be made by a blood test alone. Serum testing is commonly done as a screening test to determined increased risks of developing allergy-like symptoms. The blood tests for allergy, however, do not tell your doctor with certainty whether or not the allergens being tested for are causing your symptoms.
6. What are the most common allergic diseases?
The most common diseases caused by allergy mechanisms are those of hay fever (allergic rhinitis), asthma, eczema (allergic dermatitis), contact dermatitis, food allergy and urticaria (hives).
7. How are allergies treated ?
Allergy treatments involve 3 fundamental principles. First, avoidance of the known irritant or allergen responsible for inducing the state of hypersensitivity. Second, when avoidance of a specific allergen source such as house dust or certain pollens is impossible, then drug therapy is used. Finally, when avoidance and drug therapy fail to adequately control the inflammation involved in a person’s allergic disease, specific allergen immunotherapy (otherwise known as allergy injections) are used to help prevent the progression of the allergic disease.
It is important to point out that allergen immunotherapy is the only treatment available today that can actually change a patient’s immune system back toward normal.
Also, it is most important to remember that all allergic diseases, such as hay fever and asthma, are chronic long-standing diseases which require long-term management to better control and prevent the inflammatory mechanisms.
8. What is a Sensitizer? How does it work ?
A sensitizer, or allergen, is usually a smaller protein or at times a carbohydrate (sugar substance) which is capable at very small concentrations of inducing excessive immune responses in a genetically predisposed individual. Allergy is in this way a heritable trait. Not everyone has the genetic predisposition toward the development of allergy antibody immune responses to sensitizing agents, or allergens.
Aeroallergens are allergens present within the air. The aeroallergen contacts the human immune system by entering through the mucus membranes of the eyes, nose, throat and lung. When this aeroallergen interacts with the allergic arm of the immune system, there is set into motion a cascade of biochemical reactions resulting in immediate symptoms. When we say immediate we mean within 15-20 minutes there will be sneezing, wheezing, itchy, etc.
Some sensitizing agents can directly cause release of histamine from allergy cells even without allergy antibodies. These substances are referred to as irritants or nonspecific reacting materials.
9. How many people have allergies?
The most common cause of allergy on planet earth is the house dust mite. The house dust mite produces allergenic proteins primarily in its droppings, or fecal pellets. The incidence of allergic diseases overall in population ranges from between 23-30% of individuals. This tendency to become allergic to allergens is predetermined by the individual genetic makeup of a person.
10. Is there a time of year when Allergies are more of a problem?
The allergy season really never ends. Springtime is the tree pollen season. Summertime is the grass and weed pollen season. In the fall, people can experience both a ragweed and mold allergy season, and finally in the wintertime, people who suffer from allergies will go into the “indoor allergy season”. The most common indoor aeroallergens which can produce hay fever, sinus and asthma symptoms are those of the house dust mite, cockroach droppings, indoor mold spores and pet animals.
11. Can a person outgrow an allergy?
Most people grow into allergy, not out of it. One can, however lose sensitivity to certain foods if one totally avoids the offending food allergen. This occurs in most children who have the unfortunate experience of having hives due to cow’s milk. Later in life that same person who had hives early in infancy can tolerate milk and other cow proteins.
Unfortunately, one cannot totally avoid exposure to certain pollens, molds and dust and thus, year after year having been repeatedly exposed to these airborne proteins allergic individuals continue to have allergic diseases due to their continuous or repeated exposure to these aeroallergens.
12. Can allergies develop later in life?
Allergy does not discriminate on the basis of age. Allergic reactions can develop at any time in life whether it be age one day, one year, 20 years, 40 years or 60 years. The peak age at which allergy develops, however, is in the late teens. For reasons yet unexplained, the immune system of a 19 year old is most able to produce IgE allergy antibody responses.
13. Are there any long-term effects from allergic reactions?
Allergic reactions which occur in the sinuses or the lungs repeatedly year after year may actually result in a change in the anatomy of the body part being affected. For example, if asthma symptoms are allowed to occur without adequate control, then the inflammation involved in the disease will cause the lungs to misbehave forever regardless of continued therapy. In the past it was believed that asthma did not result in emphysema. However, recent research has indicated that a patient suffering from asthma which is out of control may develop a form of emphysema, or fixed airways disease, which is not reversible.
Asthma by its very definition, means a reversible airway obstruction which is accompanied by allergic inflammation in 90% of the cases.
14. What allergies cause fatal reactions?
The most common causes of fatal allergic reactions include severe reactions to foods such as shellfish, peanuts and cod, or to stinging insects such as yellow jackets and imported fire ants.
15. Should people wear ID bracelets for their allergic conditions?
Patients with life-threatening allergic reactions to antibiotics or bee sting reactions should definitely wear ID bracelets and should carry with them an emergency kit containing epinephrine. Contact your physician for a prescription for an Epi Pen. If you have had a severe allergic reaction in the past, you should have available in your home at all times an adrenaline kit for self-administration should it become necessary.
16. What is the best treatment for allergic disease?
The most important thing in treating any human disease is receiving an exact and accurate diagnosis of the problem. For most all patients suffering from allergic diseases such as hay fever, sinus headaches, asthma and food allergy this means a visit to a specialist in allergy and asthma.
Educated victims of allergy and asthma do much better in life than those patients who are under-diagnosed and under-treated. When patients die from asthma attacks, it’s primarily because of under-treatment by the patient and/or under-diagnosis on the part of their physician.
17. Are there particular food allergens to be aware of?
The most frequent foods responsible for causing allergic reactions are nuts, peanuts, milk, egg, wheat and soybean proteins. Unfortunately there are food preservatives which may also induce allergy symptoms. These preservatives include metabisulfite and monosodium glutamate. Metabisulfites are present in most wines which need preserving.
The diagnosis of food allergy can be difficult. Consult with your closest Board Certified Allergy & Asthma Specialist to obtain an exact diagnosis of possible food related disorders.
18. What is Allergy test?
Asthma and allergy related conditions are on rise both in terms of prevalence and severity. For an effective allergy treatment, the first step is to find out, what you are allergic to. Allergy tests are convenient and accurate, if performed and analysed by an allergist. Allergy testing can identify the specific allergen that has triggered your allergic symptoms. I have come across many myths in my patients in particular and population in general, about allergy testing. Hence i would like to share following facts about Allergy testing.
19. Who can be tested for allergies?
Adults and children of any age can be tested for allergies. It is advised in allergy related conditions such as Asthma, Allergic rhinitis, Eczema, hives or urticaria and food allergies.
20. How is allergy testing done?
Allergy testing can be done as skin tests or as blood tests. Usually, allergy tests are done under the guidance of an allergy specialist. These specialists are trained in the best methods for testing and treating allergies. Kindly ensure that you are undertaking allergy tests under the supervision of an allergy specialist.
21. How do allergy skin tests work?
There are two types of skin tests. During the first type of skin test, a drop of a suspected allergen is pricked on the surface of the skin. The test is performed on the back or forearm. Many suspected allergens are tested at the same time. If you are allergic to one of the tests, you will have redness and swelling at the test spot. Your allergist will read the test as per the severity of swelling and categorize accordingly.
22. How long does it take to get skin test results?
Skin testing is fast. For both types of skin tests, positive reactions usually appear within 20 minutes. Sometimes redness and swelling can occur several hours after skin testing. The delayed reaction usually disappears in 24 to 48 hours, but should be reported to the allergy doctor or nurse.
23. Is skin testing painful?
Skin tests have little or no pain. However, positive reactions cause mild itching red bumps which look and feel like insect bites. The itching and bumps goes away in some time.
24. Does medicine interfere with allergy skin tests?
Some medicines do interfere with allergy skin tests. The allergist will tell you if you have to change your medicine before allergy skin testing for eg first generation antihistamines ( cetrizine, fexophenadine) should be discontinued atleast 3-5 days before allergy testing.
25. When are allergy blood tests used?
An allergy blood test is often used because:
• The patient is taking a medicine that can interfere with skin testing, but cannot be stopped for a few days due to medical reasons.
• The patient suffers from a severe skin related condition such as eczema or psoriasis
• Testing with a strong allergen might lead to an extra large positive reaction
• For babies and very young children, a single needle stick for allergy blood testing is better than several skin tests.
26. How long does it take to get blood test results?
Because the blood sample must be sent to a lab for testing, it takes many days to get the results. It is recommended to get the test done from a reputed lab, as the test results are very sensitive.
27. What allergies can allergy testing find?
A test for allergies can help find allergies to pollen, molds, dust mites, animal dander, insect stings, foods and some medicines.