Atopy refers to the genetic tendency to develop allergic diseases such as allergic rhinitis, asthma and atopic dermatitis (eczema). Atopy is typically associated with immune responses to common allergens, especially inhaled allergens and food allergens.
Allergies are among the most common chronic conditions worldwide. Allergy symptoms range from making you miserable to putting you at risk for life-threatening reactions.
allergic reaction begins in the immune system. Our immune system protects us from invading organisms that can cause illness. If you have an allergy, your immune system mistakes an otherwise harmless substance as an invader. This substance is called an allergen. The immune system overreacts to the allergen by producing Immunoglobulin E (IgE) antibodies. These antibodies travel to cells that release histamine and other chemicals, causing an allergic reaction.
An allergic reaction typically triggers symptoms in the nose, lungs, throat, sinuses, ears, lining of the stomach or on the skin. For some people, allergies can also trigger symptoms of asthma. In the most serious cases, a life-threatening reaction called anaphylaxis can occur (Anaphylaxis is a serious, life-threatening allergic reaction. The most common anaphylactic reactions are to food, insect stings, medications and latex).
A number of different allergens are responsible for allergic reactions. The most common include:
- Insect stings
- Animal dander
Allergies: your physician may be able to help identify your allergy triggers. Several different types of allergy tests are used to do this.
1.Questions Your Doctor Will Ask
- What kinds of symptoms do you have?
- How long have you had them?
- When your symptoms happen, how long do they last?
- Do your symptoms come and go throughout the year, or do they last year-round?
- Do your symptoms hit when you’re outdoors, or indoors — like when you clean your home?
- Do they get worse when you’re around pets? Do you have any pets?
- Do you smoke? Does anyone in your family smoke?
- Do your symptoms keep you from doing things, or from sleeping at night?
- What makes your symptoms better? What types of treatments have you tried?
- What allergy drugs are you taking now? Do they help?
- What other medications are you taking, including prescription and over-the-counter drugs, vitamins, and herbal supplements?
- What kind of heating system do you have? Do you have central air conditioning?
- Do you have any other health conditions, like asthma or high blood pressure?
- Do you have problems with your sense of smell or taste?
- Do you get better on the weekend and worse when you go back to work?
2.Allergy Skin Test
These tests use extracts (a concentrated liquid form) of common allergens such as pollen, mold, dust mites, animal dander, and foods. Once those get in your skin, they could trigger a rash. Your skin will get irritated and may itch, like a mosquito bite.
That reaction is how the doctor can tell you’re allergic to something. When you have an allergy, your immune system will make antibodies and set off chemicals to fight off the trigger.
Scratch test, also known as a puncture or prick test: First, your doctor or nurse will look at the skin on your forearm or back and clean it with alcohol. They’ll mark and label areas on your skin with a pen. Then they’ll place a drop of a potential allergen on each of those spots. Next, they’ll scratch the outer layer of your skin to let the allergen in. (It’s not a shot, and it won’t make you bleed.)
Intradermal test: After they look at and clean your skin, the doctor or nurse will inject a small amount of allergen just under your skin.
Patch test: Your doctor could put an allergen on a patch and then stick that on your arm or back.
Plan for an hour-long appointment. The pricking part of scratch and intradermal tests takes about 5 to 10 minutes. Then you’ll wait about 15 minutes to see how your skin reacts.
Patch tests take more time, and two visits to your doctor. You’ll have to wear a patch for about 48 hours in case you have a delayed reaction to the allergen.
3.Blood Test for Allergies
You might sniffle and sneeze as the seasons change or get itchy and teary-eyed when you dust the house or pet an animal. Perhaps you start wheezing when you eat a particular food.
Allergy blood testing can help reveal what triggers your allergy symptoms and help your doctor choose the best treatment for you.
Types of Allergy Blood Tests
Allergy blood tests detect and measure the amount of allergen-specific antibodies in your blood. When you come into contact with an allergy trigger, known as an allergen, your body makes antibodies against it.
The antibodies tell cells in your body to release certain chemicals. These chemicals are what cause allergy symptoms. Immunoglobulin E (IgE) is an antibody that’s strongly linked to the body’s allergy response.
Allergy blood tests usually screen for at least 10 of the most common allergy triggers, including dust, pet dander, trees, grasses, weeds, and molds related to where you live. They are also particularly helpful in diagnosing food allergies.
4.Food Allergy Testing
Food allergies are becoming more and more common. There has been an increase in severe food allergy cases in the last 10 years, mostly driven by peanut and tree nut allergies.
In children, the most common food allergies are
- Cow’s milk
- Hen’s eggs
- Tree nuts
In adults, the most common food allergies are:
- Tree nuts
- Crustaceans (such as shrimp, crabs, and lobster)
- Mollusks (such as clams, oysters, and mussels)
- Symptoms tend to occur just after eating, inhaling, or coming into contact with the offending food. Symptoms may include reddening of the skin, hives, itchy skin, swollen lips or eyelids, tightness of the throat, wheezing, difficulty breathing, coughing, vomiting, or diarrhea.
5.Allergy Symptom Diary
If you have a food allergy, you may need to keep a food diary – and remove certain foods from your diet – to determine exactly what you’re allergic to.
The elimination diet involves removing specific foods or ingredients from your diet that you and your doctor suspect may be causing your allergy symptoms (common allergy-causing foods include milk, eggs, nuts, wheat, and soy). Your doctor will supervise this diet over a few weeks.