Allernet > Allergy FAQ
1. What does the word "allergy" mean?
The word allergy is defined in medical dictionaries as "a hypersensitive state". Allergy is derived from the Greek allos, meaning other, and ergon which means work. If a person has an allergic reaction to something, what they are really experiencing is an altered, or exaggerated reaction. Thus, the allergy patient lives in an altered state of hypersensitivity.
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 persons 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).
Allergy really has different names depending upon where in your body the reaction is occurring. If an allergic reaction occurs in your nose, eyes and sinuses physicians will call it allergic rhinitis. If the allergic explosion is occurring in the lungs, we call it asthma. All of these allergic diseases are inflammatory in nature. That is to say, there is inflammation characteristic of allergy immune mechanisms occurring in those parts of your body when we give the condition the above scientific names.
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 persons 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 patients 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 the United States 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. About 15 million Americans currently experience asthma symptoms.
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 a 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 cows 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 inflamation 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 Board Certified 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, its 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.