Understanding Allergies: Causes and symptoms

Advocate’s team of experienced allergy experts specialize in providing care and relief for all types of allergies. We provide testing for reactions to foods, seasonal allergies, bee stings and other potential triggers so you can get allergy relief. Your doctor will also recommend treatment options that could include immunotherapy (allergy shots), nasal medications and antihistamines.

What are allergies?

An allergy is a reaction to specific proteins. Your immune system views some proteins as harmful and reacts to them, causing a wide range of symptoms.

Typically, most of these proteins (allergens) are harmless and cause discomfort. Although rare, an allergic reaction can cause anaphylaxis and become life threatening and require immediate medical attention.

Anaphylaxis is a severe allergic reaction that includes symptoms such as swollen eyes, lips, hands and feet, feeling lightheaded or faint., swelling of the mouth, throat or tongue, which can cause breathing and swallowing difficulties and wheezing.

Call 911 if you are having a severe allergic reaction.

How an allergic reaction occurs

An allergic reaction happens when an allergen encounters the skin, eyes, nose, gastrointestinal (GI) tract or respiratory tract. Allergens can be inhaled, swallowed or injected.

When your immune system encounters an allergen for the first time, it creates IgE (Immunoglobulin E) antibodies. These antibodies bind to cells in your airways, skin and GI tract known as allergy cells (mast cells).

These antibodies find allergens in your body and remove them by taking them to the allergy cell and attaching them to a receptor on the cell. This triggers the cell to release histamine. This histamine causes allergy symptoms such as hives, runny nose, sneezing, digestive problems and more.

Allergy causes

Allergies are very common and can be caused by several factors. Nearly one in three adults and one in four children in the United States have a seasonal allergy, food allergy or eczema. The most common allergens include:

• Foods
• Medications
• Inhaled substances
• Insect stings
• Latex

Foods

Food allergies can cause a reaction within minutes of eating the food. Symptoms can be mild or severe and may also include anaphylaxis.

The most common food allergies:

• Eggs
• Milk
• Peanuts
• Shellfish
• Soy
• Tree nuts
• Wheat

In some cases, an allergy may develop to vegetables or fruits, including apples, citrus fruits, mangoes and berries. Fruit and vegetable allergies are uncommon and typically only affect teenagers and children.

Medications

Allergies to medications (prescription or over-the-counter) are also common and may also cause a severe reaction. The most common medications that cause an allergic reaction are:

• Penicillin and other antibiotics
• Anticonvulsants
• Aspirin, ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs)
• Prescription insulin
• Chemotherapy medications

Inhaled substances

Substances in the air that you can inhale may cause an allergic reaction. They can impact you throughout the year or seasonally. Common airborne allergens that can affect you all year include:

• Cockroaches (saliva, feces and shedding body parts that can be inhaled)
• Dust mites
• Molds
• Pet dander

Seasonal allergies depend on the area you live in. In some areas, seasonal allergies are a problem from spring through fall. In warmer climates, seasonal allergies can happen year round.

Most people with seasonal allergies are affected by tree pollination in the early spring. Grass and ragweed pollen levels increase in the late summer and fall. Not everyone has a reaction to all types of tree pollen. Symptoms of seasonal allergies could include a stuffy nose, sneezing, and itchy and watery eyes.

Insect stings

When you’re stung by a bee or other insects, they release venom into the skin. Venom is a poison and can cause an allergic reaction, including anaphylaxis, in some people. It’s important to seek immediate care if symptoms are severe.

The most common insect stings or bites that cause an allergic reaction include:

• Bees
• Fire ants
• Hornets
• Some spiders
• Wasps
• Yellow jackets

Latex

Latex allergies develop due to a reaction to rubber latex, which comes from tree sap. Latex allergies are rare, affecting only 1% of the people in the United States. Common latex products include:

• Balloons
• Bandages
• Condoms
• Rubber balls
• Rubber gloves

In most cases, a latex allergy causes mild symptoms such as hives, runny or stuffy nose, and itching. The most common latex allergy symptom is dermatitis, or skin irritation.

Understanding allergy symptoms

Allergy symptoms can vary depending on the severity of the allergy and what’s causing it. Sometimes symptoms can be mild and cause little to no discomfort. Other times they can be uncomfortable, moderate to severe, or be a medical emergency.

Some symptoms you may experience include:

Allergy testing and diagnosis

If your symptoms last longer than a week or keep coming back, schedule an appointment with an Advocate specialist for allergy testing. There are several types of allergy tests available, including a skin test, patch test and a blood test for IgE antibodies.

Using a skin prick, your doctor will use small needles to inject small amounts of potential allergens into the skin to check for a reaction. A skin test can detect allergies to foods, pollen and medications. A more advanced skin test can be performed to check for insect sting allergies or if the skin prick test was inconclusive.

Once your doctor has determined what you’re allergic to, they will outline effective treatment options to manage your symptoms and help you find allergy relief.

Effective allergy treatment options

Allergy medicines are an effective way to treat your allergy symptoms. Your doctor may recommend antihistamines (Allegra, Claritin or Zyrtec) or nasal sprays (Flonase) to help relieve your symptoms. They may also recommend decongestants such as pseudoephedrine (Sudafed) to help you relieve congestion in your chest.

If you have more severe allergies, your doctor may prescribe stronger allergy medications, steroids or bronchodilators.

Your allergy specialist may also recommend allergy shots, or immunotherapy. Allergy shots are regular injections for three to five years that contain tiny amounts of allergens that trigger your allergic reactions to help your immune system recognize them and stop reacting.

Preventing allergies in daily life

There are several allergy remedies that can be used to prevent symptoms. Avoiding contact with allergy triggers is the best allergy remedy to prevent an allergic reaction. Daily antihistamines and other medications can control symptoms and prevent or reduce allergic reactions.

Keeping your house clean and vacuuming carpets will help remove dust and pet dander inside your home. Using air purifiers and changing your air filters regularly can also help reduce allergens in your home.