An allergy is an immune system response to a foreign substance that’s not typically harmful to your body. These foreign substances are called allergens. They can include certain foods, pollen, or pet dander.
Your immune system’s job is to keep you healthy by fighting harmful pathogens. It does this by attacking anything it thinks could put your body in danger. Depending on the allergen, this response may involve inflammation, sneezing, or a host of other symptoms.
Your immune system normally adjusts to your environment. For example, when your body encounters something like pet dander, it should realize it’s harmless. In people with dander allergies, the immune system perceives it as an outside invader threatening the body and attacks it.
Allergies are common. Several treatments can help you avoid your symptoms.
The symptoms you experience because of allergies are the result of several factors. These include the type of allergy you have and how severe the allergy is.
If you take any medication before an anticipated allergic response, you may still experience some of these symptoms, but they may be reduced.
For food allergies
Food allergies can trigger swelling, hives, nausea, fatigue, and more. It may take a while for a person to realize that they have a food allergy. If you have a serious reaction after a meal and you’re not sure why, see a medical professional immediately. They can find the exact cause of your reaction or refer you to a specialist.
For seasonal allergies
Hay fever symptoms can mimic those of a cold. They include congestion, runny nose, and swollen eyes. Most of the time, you can manage these symptoms at home using over-the-counter treatments. See your doctor if your symptoms become unmanageable.
For severe allergies
Severe allergies can cause anaphylaxis. This is a life-threatening emergency that can lead to breathing difficulties, lightheadedness, and loss of consciousness. If you’re experiencing these symptoms after coming in contact with a possible allergen, seek medical help immediately.
Everyone’s signs and symptoms of an allergic reaction are different.
Skin allergies may be a sign or symptom of an allergy. They may also be the direct result of exposure to an allergen.
For example, eating a food you’re allergic to can cause several symptoms. You may experience tingling in your mouth and throat. You may also develop a rash.
Contact dermatitis, however, is the result of your skin coming into direct contact with an allergen. This could happen if you touch something you’re allergic to, such as a cleaning product or plant.
Types of skin allergies include:
- Rashes. Areas of skin are irritated, red, or swollen, and can be painful or itchy.
- Eczema. Patches of skin become inflamed and can itch and bleed.
- Contact dermatitis. Red, itchy patches of skin develop almost immediately after contact with an allergen.
- Sore throat. Pharynx or throat is irritated or inflamed.
- Hives. Red, itchy, and raised welts of various sizes and shapes develop on the surface of the skin.
- Swollen eyes. Eyes may be watery or itchy and look “puffy.”
- Itching. There’s irritation or inflammation in the skin.
- Burning. Skin inflammation leads to discomfort and stinging sensations on the skin.
Rashes are one of the most common symptoms of a skin allergy.
Researchers aren’t exactly sure why the immune system causes an allergic reaction when a normally harmless foreign substance enters the body.
Allergies have a genetic component. This means parents can pass them down to their children. However, only a general susceptibility to allergic reaction is genetic. Specific allergies aren’t passed down. For instance, if your mother is allergic to shellfish, it doesn’t necessarily mean that you’ll be, too.
Common types of allergens include:
- Animal products. These include pet dander, dust mite waste, and cockroaches.
- Drugs. Penicillin and sulfa drugs are common triggers.
- Foods. Wheat, nuts, milk, shellfish, and egg allergies are common.
- Insect stings. These include bees, wasps, and mosquitoes.
- Mold. Airborne spores from mold can trigger a reaction.
- Plants. Pollens from grass, weeds, and trees, as well as resin from plants such as poison ivy and poison oak, are very common plant allergens.
- Other allergens. Latex, often found in latex gloves and condoms, and metals like nickel are also common allergens.
Seasonal allergies, also known as hay fever, are some of the most common allergies. These are caused by pollen released by plants. They cause:
- itchy eyes
- watery eyes
- runny nose
Food allergies are becoming more common. Find out about the most common types of food allergies and the symptoms they cause.