Allergies
What is Allergies?
Allergies happen when your immune system overreacts to harmless substances in your environment. These substances, called allergens, can include pollen, dust mites, pet dander, certain foods, or mold. Your body mistakenly sees these as threats and launches a defense response.
When you encounter an allergen, your immune system produces antibodies called immunoglobulin E, or IgE. These antibodies trigger the release of chemicals like histamine, which cause the symptoms you experience. Your eosinophils, a type of white blood cell, also increase during allergic reactions. This response is your body trying to protect you, but it creates uncomfortable symptoms instead.
Allergies affect more than 50 million Americans each year. They can appear at any age, even if you never had them before. Some people have mild reactions, while others experience severe symptoms that disrupt daily life. Understanding your immune response through blood testing helps identify what is happening inside your body.
Symptoms
- Sneezing and runny or stuffy nose
- Itchy, watery, or red eyes
- Scratchy throat or coughing
- Skin rashes, hives, or eczema
- Swelling of the lips, tongue, or face
- Wheezing or shortness of breath
- Stomach pain, nausea, or diarrhea with food allergies
- Fatigue or difficulty concentrating
Some people have symptoms only during certain seasons, while others deal with them year-round. Children may have different symptoms than adults, especially with skin reactions.
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Causes and risk factors
Allergies develop when your immune system becomes sensitized to a specific substance. Genetics play a significant role, so you are more likely to have allergies if your parents do. Environmental factors, early childhood exposures, and gut health also influence whether you develop allergies. Common triggers include tree pollen, grass, ragweed, dust mites, pet dander, mold, insect stings, and foods like peanuts, shellfish, eggs, or milk.
Your immune system produces interleukin-4, or IL-4, which drives the allergic response. High levels of IL-4 tell your immune cells to make more IgE antibodies. This creates a cycle where exposure to allergens keeps triggering reactions. Lifestyle factors like stress, poor diet, lack of sleep, and exposure to pollution can make allergies worse by affecting immune function.
How it's diagnosed
Doctors diagnose allergies through a combination of your medical history, physical exam, and testing. Blood tests measure markers of immune activity that indicate allergic responses. Elevated eosinophils suggest your body is reacting to allergens or other triggers. Tests for immune status and interleukin-4 show how actively your immune system is producing allergic antibodies.
Rite Aid offers blood testing that measures key immune markers linked to allergies. Our panel includes eosinophils, immune status, and interleukin-4 testing at Quest Diagnostics locations nationwide. Getting tested helps you understand what is happening inside your body so you can work with your doctor on the right treatment plan.
Treatment options
- Avoid known allergens when possible by tracking your triggers
- Use air purifiers with HEPA filters to reduce indoor allergens
- Keep windows closed during high pollen days
- Wash bedding weekly in hot water to kill dust mites
- Take antihistamines to block histamine and reduce symptoms
- Use nasal corticosteroid sprays to reduce inflammation
- Try decongestants for short-term relief of nasal congestion
- Consider immunotherapy, also called allergy shots, for long-term relief
- Eat an anti-inflammatory diet rich in omega-3 fatty acids and vegetables
- Manage stress through meditation, exercise, or therapy
- Work with your doctor to monitor immune markers with regular testing
Concerned about Allergies? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Seasonal allergies occur during specific times of year when plants release pollen. Tree pollen peaks in spring, grass pollen in late spring and summer, and ragweed in fall. Year-round allergies, also called perennial allergies, happen throughout the year from indoor triggers like dust mites, pet dander, or mold.
Yes, you can develop allergies at any age, even as an adult. Changes in your environment, moving to a new location, hormonal shifts, or increased stress can trigger new allergies. Your immune system can become sensitized to substances it previously tolerated without problems.
Blood tests measure immune markers like eosinophils and interleukin-4 that show how your immune system responds to allergens. Skin prick tests expose your skin to specific allergens to see if you react. Blood tests are safer for people with severe allergies or skin conditions and can be done while taking antihistamines.
Eosinophils are white blood cells that increase when your body encounters allergens. They release chemicals that fight what your immune system perceives as threats. High eosinophil levels on blood tests indicate your immune system is actively responding to allergens or other triggers like parasites.
Yes, diet can influence allergy symptoms by affecting inflammation and immune function. Eating omega-3 fatty acids from fish, avoiding processed foods, and consuming probiotic-rich foods support healthy immune responses. Some people also react to foods that cross-react with their environmental allergens, like birch pollen and apples.
Interleukin-4, or IL-4, is a signaling molecule that tells your immune system to produce IgE antibodies. These antibodies drive allergic reactions by triggering histamine release. High IL-4 levels indicate your immune system is primed for allergic responses and actively creating the conditions for symptoms.
Testing twice a year helps track how your immune markers change with seasons and treatment. Regular monitoring shows whether lifestyle changes or medications are working. It also helps catch increases in immune activity before symptoms become severe.
Yes, stress affects immune function and can worsen allergy symptoms. When you are stressed, your body produces cortisol and other hormones that can increase inflammation. Stress also disrupts sleep and gut health, both of which influence how your immune system responds to allergens.
Talk to your doctor about prescription options like stronger antihistamines, nasal sprays, or leukotriene inhibitors. Immunotherapy through allergy shots or tablets can retrain your immune system for long-term relief. Blood testing can also reveal immune markers that guide more targeted treatment approaches.