Can Allergies Cause Wheezing?

Allergies occur when the body reacts abnormally to certain substances that are otherwise harmless. When the body comes into contact with these substances, the immune system begins producing antibodies. This leads to the production of other chemicals in the body, like histamine. These chemicals cause allergy symptoms along with inflammation. The reason the body attacks some substances in some people but not others isn’t fully understood.

For some people, allergic reactions affect the lungs and airways. This can lead to asthma symptoms, including wheezing.

Wheezing is defined by a high-pitched whistling noise made when you breathe. Most wheezing occurs when breathe you out, but it can sometimes be heard when you breathe in. You may also have difficulty breathing when you’re wheezing.

Wheezing can sometimes be a sign of a serious problem. Call your doctor if:

• you’re experiencing wheezing, even mild wheezing, for the first time
• your wheezing is recurrent
• you’re wheezing but have no history of allergies

You should get immediate emergency care if the wheezing:

• is accompanied by difficulty breathing, rapid breathing, or bluish skin color
• starts suddenly after you’re stung by a bee, have taken medication, or have eaten an allergy-causing food (serious food allergies are often related to shrimp, shellfish, nuts, milk, egg, soy, and wheat)
• starts after you choke on a small object or piece of food
• is accompanied by hives or swelling of your lips or face

If you visit your doctor with wheezing symptoms, they’ll likely begin by giving you a physical exam to rule out possible health conditions. If your doctor finds abnormalities with your lungs and airways, they’ll measure how much air moves in and out as you breathe with lung function (pulmonary) tests.

Before and after performing pulmonary tests, your doctor will have you take a medication called a bronchodilator that opens up your airways. They’ll use special medical devices that you breathe into to perform the following tests:

• Spirometry. This measures how well your lungs function compared to healthy lungs.
• Peak flow. This test that measures how hard you can breathe out. If your airways are narrowing, this number will be lower than expected.

Additional tests to diagnose the cause of wheezing include:

• Methacholine challenge. Your doctor will administer methacholine, a substance that triggers asthma. If you react to the methacholine, you likely have asthma.
• Nitric oxide test. Your doctor will use a special device to measure the amount of nitric oxide gas you have in your breath. High levels of nitric oxide in your breath may indicate that your airways are inflamed.
• Imaging tests. Your doctor may order imaging tests such as chest X-rays and a CT scan of your lungs and nose cavities (sinuses) to look for any physical problems or diseases that may be causing your wheezing.
• Allergy testing. Your doctor will perform a skin or blood test to identify whether or not your body reacts to common allergens, such as pet hair, dust, pollen, molds, and common foods. If your doctor identifies allergy triggers, they might recommend allergy shots (immunotherapy) to help minimize your allergic reactions.
• Sputum eosinophils. Your doctor will ask you to cough up a discharge called sputum, which is mucus from the lungs. They’ll look at it under a microscope to check for a certain type of white blood cell called eosinophils. These cells are present when asthma symptoms develop.
• Provocative testing for exercise- and cold-induced asthma. Your doctor will measure your lung function before and after exercise or a cold air challenge

Your doctor will analyze the results of your tests to arrive at the appropriate diagnosis.

If they suspect you have allergies, your doctor may ask you to keep a detailed diary of the foods you eat, symptoms, and possible allergy triggers other than food. If diagnostic tests suggest you have asthma, your doctor will classify its severity using a symptom-based scale:

• Mild intermittent: You experience mild asthma symptoms no more than two days a week, and have nighttime symptoms no more than two nights a month.
• Mild persistent: You experience asthma symptoms more than twice a week but not daily, and have nighttime symptoms three to four times a month.
• Moderate persistent: You experience asthma symptoms daily and more than one night a week, but not every night.
• Severe persistent: You experience asthma symptoms throughout the day on most days and almost every night.

Treatment plans for allergies and asthma vary. When addressing wheezing as a symptom of allergies or asthma, it can be minimized with medications or the use of an inhaler.

Taking all of your prescribed medications and avoiding your allergy or asthma triggers can help keep wheezing at bay. Medications are usually effective at alleviating wheezing.

However, allergies and asthma aren’t completely curable. For that reason, it’s important to stick to your treatment plan. Talk to your doctor if your wheezing symptoms persist or worsen after your diagnosis.