/ Allergies
Common Allergies: What are the Different Types?

Having allergies is a pretty common ailment. Each year, over 50 million Americans experience an allergy of some type, and allergies are the 6th most common cause of chronic illness in the United States. They can occur in winter, spring, summer or fall; it all depends on what a person is allergic to. Most seasonal allergies, like a pollen allergy, are airborne. Non-seasonal allergies, like a food allergy, can affect you anytime of the year. Allergy types include:

  • Respiratory and eye allergies
  • Food allergies
  • Insect allergies
  • Drug allergies
  • Skin allergies

Allergy Definition

What are allergies? Allergies are immune responses to harmless substances that the body interprets as a threat. With allergies, the body means well, but it is overreacting to a substance that it should not necessarily be reacting to.

What causes allergies? A wide variety of substances can trigger allergies, all of which are called allergens.

Allergy Definition:
An allergen is any substance that triggers an allergic reaction.

Allergens can be particles in the air, oils or metals that contact the skin, certain foods in the digestive tract, drugs, or chemicals injected by insects. Peanuts might be an allergen for some people, but if you're not allergic to peanuts, then peanuts are not an allergen to you.

During an allergic reaction, the body's immune system produces histamines to help the body usher allergens out.

Allergy Definition:
Histamines — are chemicals stored in mast cells that have a variety of functions in the body relating to digestion, brain activity, and immune responses. Antihistamines are medications that block mast cells from releasing histamines, and thus reducing the symptoms of allergies.

One function of histamines during an allergic reaction is to increase blood flow and cause inflammation, which signals the body that something is wrong. Symptoms of allergies such as sneezing, coughing, itching, or tearing up are a body's way of reacting to histamine production and expelling the perceived threat from your system. Symptoms of allergies can be highly irritating, especially because we know the allergen isn't actually harmful.

In extreme allergic reactions, the body can experience anaphylaxis. Seek immediate medical attention if someone is experiencing severe allergic reactions.

Allergy Definition:
Anaphylaxis is an extreme overreaction that can cause severe skin reactions, hypotension, constriction of airways, swollen tongue or throat, a rapid yet weak pulse, dizziness, or fainting. Anaphylaxis can be fatal.

Specific allergens known for anaphylaxis include certain foods (e.g. peanuts), insect venom (e.g. bee stings), certain medications, and latex.

Are Allergies Contagious?

Symptoms of allergies such as sneezing, runny nose, nasal congestion, coughing or diarrhea can be similar to viral infections like a cold. Colds are contagious, but are allergies contagious? No. They are triggered by allergens rather than by direct or indirect contact with another person experiencing allergies.

Allergens can be transferred from person to person (e.g pollen in somebody's hair or clothes, residue from tree nuts can be transfered by hands, etc.), however being allergic is not something that can be transferred from person to person, nor are the symptoms of allergies.

Common Allergies and Allergy Types

A large variety of allergens can trigger common allergies. What causes allergies might be different from person to person, but they most likely fall into one of these eight allergy types:

  1. Pollen is a fine particle by many different plant species that gets released into the air in huge quantities. This is a respiratory allergy that occurs seasonally because pollen production mainly occurs during the spring and summer. The most common allergies related to pollen include:
  • Trees, which release pollen mainly in the spring. Some common species include ash, aspen, birch, box elder, cedar, cottonwood, elm, juniper, maple, mulberry, oak, palm, pine, sycamore, and willow.

  • Grasses, which release pollen mainly in the summer months. There are many different types of grasses; common allergens include Bermuda, Johnson, Kentucky, Orchard, Redtop, Rye, Sweet vernal, and Timothy grasses.

  • Weeds also release pollen through the summer and even into the fall. One of the most common allergies from a weed is for ragweed, which can send pollen hundreds of miles with the help of a little wind. Other weeds that cause common allergies include cockleweed, pigweed, Russian thistle, sagebrush, and tumbleweed.

    Symptoms of pollen allergies can be reduced with some preventative measures. Pollen count forecasts can be helpful indicators of when to avoid the outdoors. If pollen allergies are problematic for you try washing hair or changing clothes after being outside. A gentle breeze coming in through the windows is nice in the spring and summer, but keeping windows and doors closed can help minimize the amount of pollen that gets into your household.

  1. Dust Mites are tiny bugs that are relatives of ticks and spiders. They feed on dead skin cells that have shed off of human bodies. They thrive in household environments such as beds, couches, and carpets. They are too small to see by the naked eye so don't go looking for them, but they are there.

    Dust mites thrive in damp and warm climates. For those who are allergic to dust mites, running an air conditioner and dehumidifier to keep the house in a humidity range of 30% to 50%. Consider removing carpet if there is any and possibly invest in dust mite covers for mattresses, box springs, and pillows (or use a hypoallergenic pillow). Dust frequently and wash bed sheets weekly in hot water.

  2. Insects stings and injections from bees, wasps, hornets, yellow jackets, or fire ants typically cause some type of reaction. More rarely, insect stings can result in anaphylaxis. It is very important to carry epinephrine shots with you if you are allergic to these insects. Anaphylaxis is life threatening, and epinephrine can help save a life. If an anaphylactic reaction occurs, inject epinephrine immediately and contact 911.

  3. Drugs can cause allergic reactions in some people. The most common allergies related to medicine are penicillin and aspirin. Other common allergies related to drugs include certain antibiotics, insulin, anti-seizure drugs, sulfa drugs, and barbiturates. Certain people might experience anaphylaxis in response to drug allergens. If this occurs, inject epinephrine and call 911.

  4. Foods of various types can cause allergies among people. However, allergies and food intolerances are often mistaken for each other.

Allergy Definition:
Food allergy vs. Food intolerance — A food allergy involves an immune response to a certain food. A food intolerance indicates a specific food cannot be digested properly, although it does not involve an immune system response.

There are many food allergies that exist, but the most common allergies relating to food are from these eight otherwise tasty options:

  • cow milk

  • tree nuts (e.g. almonds, Brazil nuts, cashews, macadamia nuts, pistachios, pine nuts, and walnuts)

  • eggs

  • peanuts (a legume rather than a nut and distinct from tree nut allergies)

  • shellfish (e.g. crayfish, lobster, prawns, scallops, shrimp, and squid)

  • fish

  • wheat (a wheat allergy is an allergic response to wheat proteins and is distinct from celiac disease and gluten sensitivities, although symptoms may be similar)

  • soy

    If you think you might have a food allergy, but aren't sure if it is an allergy, sensitivity, or intolerance; a doctor visit is warranted. Their diagnosis might be based exclusively on dietary and reaction history of the patient, or might include skin tests, blood tests, or a double-blind food challenge.

  1. Latex and other skin allergies fall under the definition of contact dermatitis.

    Latex is one of the most common allergies for the skin, but other substances like plant oils (e.g. poison ivy, poison oak, and poison sumac), sunlight, beauty products, fragrances, or metals (e.g. nickel) can also cause an allergic reaction.

    Some skin reactions might appear to be signs of allergies, but don't involve an immune response and thus are not allergenic. An example is irritant contact dermatitis, where an irritant removes protective oils from the skin, which subsequently results in a rash or similar symptom.

Allergy Definition:
Contact Dermatitis is an allergy in response to something touching your skin. Redness, itchiness, and rash are common symptoms. Atopic Dermatitis is an allergic response of the skin that produces immunoglobulin.

  1. Mold allergies are similar to pollen in that microscopic particles get into the air, then into your nose and eyes causing allergy symptoms. Mold does not produce pollen though, rather it produces spores. Mold thrives in damp areas such as bathrooms and basements. To help mitigate symptoms from mold allergies, use a dehumidifier and air conditioning unit to help keep humidity down. Mold also does well in the fall when leaves fall. Wearing a mask while raking leaves can help reduce symptoms from mold allergies.

  2. Pet Dander or even proteins from a pet's skin oils or saliva can trigger an allergic reaction. Common allergies to pets include:

  • dogs
  • cats
  • birds
  • cockroaches (although they aren't exactly a pet, they are common inside of households and can trigger an allergic response in a similar manner as do pets)

When to Contact a Doctor

Most symptoms of common allergies are mild and might be treated with over-the-counter medications, or not be treated at all. Contact a doctor if you experience any of the following:

  • Chronic sinus infections, congestion, or difficulty breathing.
  • Symptoms of allergies several months out of the year.
  • If over-the-counter treatments do not help, or cause undesirable side-effects.
  • Asthma or allergies inhibit day-to-day activities or quality of life.
  • Warning signs of serious asthma attacks such as: difficulty breathing, wheezing or coughing, or tightness in the chest.

Medicine for allergy relief can cause side effects and complications when combined with other drugs. Talking to a doctor before taking over-the-counter medications won't hurt; they might help you choose what medication is best for you. They might also help you get allergy testing to figure out what exactly you are allergic to. It is particularly important to contact a doctor before using allergy medicine if:

  • Pregnant or breast-feeding
  • Chronic health conditions exist such as glaucoma, diabetes, osteoperosis, high blood pressure, etc.
  • Taking other medications
  • Treating allergies in a child
  • Treating allergies for elderly patients
  • Current allergy medicine isn't working
    A visit with a doctor or allergist might include:
  • Allergy testing
  • Education
  • Prescriptions
  • Immunotherapy
    A visit with a doctor or allergist might include:
  • Allergy testing
  • Education
  • Prescriptions
  • Immunotherapy, which is a treatment that periodically injects allergens into the body with the goal of desensitizing the individual, resulting in relief

It is extremely important to seek immediate medical attention if someone is experiencing an allergic reaction known as anaphylaxis. If this occurs, administer an epinephrine shot and call 911 immediately. Such reactions are life-threatening, and you should not wait to see if symptoms dissipate.

If you think you might have an allergy or need medical advice on managing symptoms of allergies, call or book online with PlushCare to set up a phone appointment with a top U.S. doctor today. Not sure whether you have allergies? PlushCare also offers premium allergy testing. Call or book your appointment today to get your symptoms taken care of. To learn more about allergy testing, click here.

Read more of our Allergy series:

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Ryan Quinn

Ryan Quinn

Ryan has a background in geochemical research and enjoys writing on technical subjects like health and science. He lives in Salt Lake City, UT and can be found recreating in the local mountains.

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