Even if you have allergies or know someone who does, allergies themselves can be a bit of a mystery, especially when it comes to changing symptoms of an allergic reaction. The answers to these 4 questions could shed light on what’s common and not-so-common about them.
1. Why do some people have allergies and others don’t?
Simply put, allergies are based on your immune system. And not all immune systems respond alike. If you suffer from allergies, your immune system is sensitive to something — called an allergen — that is normally harmless. When you come into contact with the allergen, your body releases various chemicals into your bloodstream. These chemicals (the main one being histamine) cause inflammation and an allergic reaction.
There’s a genetic component to all this. You have a 50% chance of developing an allergy if one of your parents has one; 75% chance if both of your parents do. But you may not be allergic to the same thing as them.
2. What are common allergies and symptoms?
Seasonal allergic rhinitis is more commonly known as hay fever. Inhaling certain airborne particles — like pollen from grass, weeds, trees and flowers — can trigger an allergic reaction, which can include:
- Runny, itchy nose
- Sneezing and nasal congestion
- Scratchy throat, coughing, wheezing
- Itchy eyes, swollen eyelids
If you suffer from asthma or dermatitis, having allergic rhinitis too is common.
Food allergies, which are caused by a protein found in certain foods (like peanuts, tree nuts and seafood) can be quite serious. The most common symptoms of a food allergy include:
- Swollen throat, tongue, lips, eyes or face
- Hives, rash or itchy skin
- Pale or flushed face
- Difficulty breathing or swallowing
- Feeling weak, faint or losing consciousness
- Rapid pulse
- Drop in blood pressure
- Cramps, vomiting or diarrhea
Dust allergies are actually allergies to dust mites — microscopic animals that live in household dust. They’re generally harmless (meaning they don’t bite or carry diseases) but some people are allergic to them. If you’re one of them, your symptoms can include:
- Itchy, runny nose
- Itchy, watery eyes
- Trouble breathing, coughing, wheezing
- Tightness in your chest
- Itchy, red rashes, or small blisters on your skin
If you’re allergic, dust mites can also trigger asthma or eczema.
Pet allergies are actually allergies to animal dander (skin flakes) or to a protein found in your pet’s saliva or urine. Common allergies include itchy, watery eyes, congestion and sneezing.
Insect stings or bites — specifically the insect venom — can also cause an allergic reaction. Most of us have experienced an insect bite and felt the pain, swelling and redness that it can cause. But if you have an allergy, symptoms are quite worse, including:
- Extensive swelling and redness that lasts more than 6 days
- Low fever
Latex (including latex gloves and latex condoms) is another common allergy. Actually, it’s the proteins found in latex that may cause an allergic reaction. And symptoms aren’t just limited to your skin:
- Irritated and watery eyes
- Runny nose, sneezing
- Coughing, wheezing and shortness of breath
- Itchy skin, rash or hives
- Digestive problems
Some of these allergies can result in severe, life-threatening symptoms. Read more about these severe reactions — called anaphylaxis — in the next answer.
3. What is anaphylaxis?
Anaphylaxis is the most severe allergic reaction. Reactions can escalate very quickly (sometimes within seconds or minutes of exposure to the allergen) and in severe cases can be deadly. Symptoms usually start within minutes but sometimes appear a half-hour or more after coming into contact with an allergen.
The most common causes or triggers include food, insects (venom), some medication, and latex. An anaphylaxis can also be idiopathic, meaning it has no known cause.
These symptoms can be very serious, and involve one or more of the following areas:
- Skin — itching, hives, flushing, paleness (“going white”)
- Throat — swelling, difficulty swallowing, tight or constricting, hoarse
- Lungs — trouble breathing, shortness of breath or wheezing
- Nose — congestion
- Lips and tongue — tingling or swelling
- Heart — weak pulse, rapid heart-rate or palpitations
- Blood pressure to drop — dizziness, fainting, shock, close consciousness
- Digestive system — feeling nauseous, vomiting, diarrhea
- Emotions — fear, stress, anxiety, panic
4. Can allergy symptoms change over time?
They can. Actually, your symptoms can be quite different every time you’re exposed to the same allergen. Generally, your first allergic reaction to an allergen may be mild but get worse the more you’re exposed to it. And while some allergies are with you for life, some may seem to get better over time.
Allergic reactions are also very personal: You may instantly start sneezing around a particular allergen; someone else with the same allergy might feel it somewhere else (like their chest).
Whatever your symptoms, never ignore them when they start — especially if you need medical treatment.
Want more information and support? Search “allergies” in Find Support for organizations in your area.