Allergies

According to the CDC, more than 50 million Americans suffer from allergies each year, making it the 6th most common cause of chronic illness in the U.S. Allergies occur when your body's immune system overreacts to certain foreign substances (allergens) that are normally harmless in most people. Allergens can be anything from certain foods, pollen, dust mites, cockroaches, pet dander, mold spores, insect stings, or certain medications. When you come into contact with an allergen, your immune system overreacts, producing antibodies called immunoglobulin E (IgE). IgE antibodies are proteins that attach themselves to mast cells and trigger the release of certain chemicals, such as histamine, which lead to allergy symptoms.

The severity of allergies will vary from person to person. It can range from minor symptoms such as sneezing, runny or stuffy nose, itching, or watery eyes to anaphylaxis, a possibly life-threatening severe allergic reaction. While most allergies cannot be cured, treatments can help relieve your allergy symptoms.

Allergies are caused by an abnormal response of your immune system to substances that are typically harmless to most people. These substances, known as allergens, can trigger an allergic reaction in certain individuals. Common allergens include:

• Pollen: Pollen from trees, grasses, and ragweed can cause allergic rhinitis (hay fever) symptoms.
• Dust Mites: These tiny insects thrive in household dust and can trigger allergic reactions when their waste particles are inhaled.
• Animal Dander: Allergens found in the skin flakes, urine, and saliva of pets like cats, dogs, birds, and rodents can cause allergic reactions.
• Mold Spores: Mold spores can be found indoors and outdoors and can trigger allergic reactions in some people, particularly in damp or humid environments.
• Insect Stings: The venom from stinging insects like bees, wasps, hornets, and fire ants can cause allergic reactions in susceptible individuals.
• Certain Foods: Common food allergens include peanuts, tree nuts, eggs, milk, soy, wheat, fish, and shellfish.
• Medications: Some medications, such as antibiotics (e.g., penicillin), nonsteroidal anti-inflammatory drugs (e.g., aspirin, ibuprofen), and certain prescription drugs, can cause allergic reactions in some people.
• Latex: Latex products, such as gloves, condoms, and balloons, can trigger allergic reactions in individuals with latex allergy.

The exact reasons why some individuals develop allergies while others do not are not fully understood, but it's believed to involve a combination of genetics and environmental factors. Also, exposure to allergens at an early age and certain lifestyle factors may play a role in the development of allergies.

Allergy symptoms will depend on the specific allergen involved and can affect your sinuses, airways, nasal passages, digestive system, and skin. These symptoms can range from very mild to a life-threatening reaction called anaphylaxis.

Hay fever, also called seasonal allergies or allergic rhinitis, may cause common allergy symptoms such as:

• Sneezing
• Itchy eyes or skin
• Stuffy or runny nose
• Conjunctivitis (red, swollen or watery eyes)

A food allergy may cause:

• Tingling in your mouth
• Hives
• Swelling of your face, lips, tongue, or throat
• Anaphylaxis

An insect allergy (bites and stings) may cause:

• Swelling in the area where you were stung/bit
• Hives or itching all over your body
• Coughing, wheezing, chest tightness, or trouble breathing
• Anaphylaxis

A drug allergy may cause:

• Itchy skin
• Hives or rash
• Shortness of breath or wheezing
• Facial swelling
• Anaphylaxis

Atopic dermatitis, which is an allergic skin condition known as eczema, may cause your skin to:

• Peel or flake
• Itch
• Become red

Anaphylaxis

Some types of allergies to medications, insect bites/stings, and foods, can cause anaphylaxis. It is a life-threatening medical emergency and can cause serious complications. Symptoms of anaphylaxis include:

• A big drop in your blood pressure
• Severe shortness of breath and trouble breathing
• Skin rash
• Lightheadedness
• Nausea/vomiting
• A rapid, weak pulse
• Loss of consciousness

Allergies are typically diagnosed through a combination of the following:

• Medical History: The healthcare provider will ask you detailed questions about your symptoms, including when they occur, how long they last, and any factors that seem to trigger or worsen them. They may also inquire about your personal and family medical history, as allergies can have a genetic component.
• Physical Examination: The healthcare provider will conduct a physical examination, focusing on areas of the body that are commonly affected by allergies, such as the skin, nose, and lungs. They may look for signs of allergic conditions like eczema, nasal congestion, or asthma.

• Allergy Testing: Allergy tests help identify specific allergens that may be causing your symptoms. There are several types of allergy tests:

  • Skin Prick Test: This is the most common allergy test. A small amount of allergen extract is placed on your skin (usually on your forearm or back), and then a small needle prick is made to allow the allergen to enter your skin. If you're allergic to a particular substance, you'll develop a raised, red bump (called a wheal) at the test site within about 15-20 minutes.
  • Blood Test (Specific IgE Test): Also known as RAST (radioallergosorbent) testing or ImmunoCAP testing, this blood test measures the levels of specific IgE antibodies to particular allergens in your blood. It's particularly useful if you have a skin condition or are taking medications that may interfere with skin prick testing.
  • Patch Test: This test is used to diagnose contact dermatitis, a type of allergic skin reaction caused by direct contact with certain substances. Small amounts of common allergens are applied to patches that are then placed on your skin for 48 hours. The patches are removed, and the skin is examined for any allergic reactions.
  • Elimination Diet: In cases of suspected food allergies, your healthcare provider may recommend an elimination diet, where you temporarily remove suspected trigger foods from your diet and then gradually reintroduce them while monitoring for symptoms.
• Allergy Challenge Test: In some cases, if the results of other allergy tests are inconclusive or if your healthcare provider suspects a severe allergy, they may recommend an allergy challenge test. During this test, you are exposed to a small amount of the suspected allergen under medical supervision to observe any allergic reactions.

Based on the results of these tests and your medical history, your healthcare provider or allergist can confirm the presence of allergies, identify specific allergens, and develop a treatment plan tailored to your needs.

Allergy treatment aims to relieve symptoms, reduce the frequency and severity of allergic reactions, and improve your quality of life. Treatment options vary depending on the type and severity of the allergy but may include:

• Avoidance: The first step in managing allergies is to avoid or minimize exposure to known allergens. This may involve measures such as keeping your windows closed during high pollen seasons, using allergen-proof bedding to reduce exposure to dust mites, and avoiding foods or substances that trigger allergic reactions.

• Medications:

  • Antihistamines: These medications help relieve symptoms such as sneezing, itching, and runny nose by blocking the effects of histamine, a chemical released during allergic reactions. Antihistamines are available over-the-counter or by prescription in various forms (tablets, capsules, liquids, nasal sprays, and eye drops).
  • Decongestants: Decongestants help relieve nasal congestion by shrinking swollen blood vessels in the nasal passages. They are available as oral tablets or nasal sprays, but nasal spray decongestants should not be used for more than a few days at a time to avoid rebound congestion.
  • Nasal Corticosteroids: These medications reduce inflammation in the nasal passages, helping to relieve symptoms such as nasal congestion, sneezing, and runny nose. They are available as nasal sprays and are often used as a first-line treatment for allergic rhinitis.
  • Leukotriene Modifiers: These medications block the action of leukotrienes, inflammatory chemicals involved in allergic reactions. They are used to treat asthma and allergic rhinitis.
• Allergy Shots (Immunotherapy): Immunotherapy involves gradually exposing your body to increasing amounts of allergens over time to desensitize your immune system and reduce allergic reactions. Allergy shots are typically recommended for individuals with severe allergies who do not respond well to other treatments. As an alternative to injections, you can try prescription tablets or drops that dissolve under the tongue (sublingually). Sublingual immunotherapy is only available for grass and ragweed allergies, however.
• Emergency Epinephrine: If you have severe allergies to certain foods, insect stings, or medications that can lead to anaphylaxis, carrying an epinephrine auto-injector (e.g., EpiPen) is essential. Epinephrine can quickly reverse severe allergic reactions and is used as an emergency treatment for anaphylaxis.

• Other Treatments:

  • Allergy Nasal Filters: These are devices inserted into the nostrils to filter out allergens from the air, helping to reduce symptoms of allergic rhinitis.

  • Saline Nasal Irrigation: Nasal irrigation with a saline solution can help clear nasal passages and reduce nasal congestion and inflammation.

  • Barrier Methods: For individuals with latex allergies, using latex-free gloves, condoms, and other products can help prevent allergic reactions.

It's important to work with your allergist or healthcare provider to find a treatment plan that works for your allergies, as well as to regularly monitor your symptoms and adjust treatment as needed.

Sources

• Allergies. Asthma and Allergy Foundation of America. https://www.aafa.org/allergies. Accessed Apr. 1, 2024.

• Allergies 101. American College of Allergy, Asthma & Immunology. https://acaai.org/allergies/allergies-101/. Accessed Apr. 1, 2024.
• Allergens. National Institute of Environmental Health Sciences. https://www.niehs.nih.gov/health/topics/agents/allergens. Accessed Apr. 1, 2024.
• Allergy Symptoms. Asthma and Allergy Foundation of America. https://aafa.org/allergies/allergy-symptoms/. Accessed Apr. 1, 2024.