When a person has an allergic reaction, there may be a whistling sound that is more noticeable when they exhale. This sound is wheezing.
During an allergic reaction, the throat and lungs may tighten. In this case, the body needs to work harder to take in enough air, which can lead to a high-pitched sound when the person exhales.
Various factors can cause wheezing, and identifying the right one is crucial in providing treatment. Some possible causes include:
An allergic reaction is how the body responds to a foreign substance, called an allergen, that it misidentifies as harmful.
This reaction can cause symptoms in the:
- stomach lining
Examples of allergens that can cause wheezing include:
- pet hair
- certain foods
- insect stings
- certain medications
Inflammation of the airways
When the body detects an allergen, it tries to reject it by producing antibodies and chemicals, such as histamine. Histamine causes the airways to become inflamed and constricted, and it also causes the body to produce mucus to help expel the allergen.
As a result, the airways become narrower. When a person breathes through narrowed airways, the air is forced through a smaller-than-usual space, and a whistling sound can result. This sound is wheezing.
Some causes of wheezing result in short-lived symptoms. Others can cause symptoms that are more serious or longer lasting.
The main symptom of allergic wheezing is the sound itself. Some people describe it as high-pitched, musical, whistle-like, or squeaky. It can be accompanied by a cough and a feeling of pressure in the chest.
Wheezing is most noticeable during exhalation. A person may also experience discomfort in their throat or chest.
When an allergic reaction causes the throat to tighten, it can produce stridor, another high-pitched sound. This stems from difficulty getting air into the body.
Not everyone with allergic wheezing has allergic asthma. But many people with asthma have attacks that are triggered by allergens. In fact, allergic asthma is the most common type of asthma, affecting about 60% of people with the condition.
Allergic asthma is a long-term condition. Another name for it is “allergen-induced asthma.”
Beyond wheezing, people with this type of asthma usually experience:
- shortness of breath
- rapid breathing
- chest tightness
People with more serious allergies can have a severe reaction called anaphylactic shock. If this happens, the person needs medical care immediately.
If wheezing accompanies any of the following, it could indicate anaphylactic shock:
- difficulty breathing
- rapid breathing
- a bluish tinge to the skin
- swelling of the face or lips
Other underlying conditions
Wheezing is usually a response to allergens, though it can stem from an underlying condition, such as an infection. It may also be a sign of other underlying health conditions, including chronic obstructive pulmonary disease, known as COPD, or heart disease.
If a person has no history of allergies or asthma, wheezing may be a cause for concern. People should speak to the doctor if they:
- have wheezing for the first time
- experience recurrent wheezing
- have pain while breathing
A doctor first performs a physical exam, which helps them rule out underlying health conditions.
Next, they test lung function by measuring how much air moves in and out when a person breathes. The doctor may administer a drug called a bronchodilator to open up the airways and help with their assessment.
If the cause of wheezing is not yet apparent, the doctor may:
- administer specific drugs that trigger asthma
- measure the nitric oxide in the person’s breath, which can indicate airway inflammation
- request a chest X-ray or CT scan
- perform skin and blood tests for specific allergies
If test results point to asthma, the doctor will ask how often the symptoms occur to gauge the severity of the condition.
Treatment for wheezing depends on whether it is caused by:
- seasonal or environmental allergies
- allergic asthma
- anaphylactic shock
- other medical conditions
Seasonal or environmental allergy treatments
The best approach depends on the allergen, which may include:
- Pollen. A reaction to pollen is called hay fever or allergic rhinitis, and allergy medications can help.
- Dust. The best way to treat wheezing that stems from an allergy to dust mites is to clean carpets, bedding, and furnishings and reduce household humidity.
- Pet hair. The saliva, skin flakes, and urine that collect when pets shed their hair can cause allergies. Regular vacuuming can help.
- Certain foods. An allergist can help determine which food is responsible, and a person usually needs to eliminate it from their diet.
Allergic asthma treatments
Most people with asthma respond best to a combination of two types of treatment. These are:
- Quick-relief medicines that expand the airways, including inhaled beta-2 agonists and anticholinergics.
- Long-acting drugs to prevent symptoms, such as inhaled corticosteroids and immunomodulators that a person takes every day.
A doctor will work with a person to find the best combination of these treatments.
Anaphylactic shock treatments
When wheezing is part of anaphylactic shock, the person needs emergency treatment, so someone should contact 911 or the local emergency number. If the person has a known allergy, they may have an adrenaline auto-injector.
Before first responders arrive, it is important to:
- lay the person down
- administer an injection with the auto-injector, if there is one
- remove the allergen
If the injection is not available, a first responder will give an adrenaline shot when they arrive.
A variety of factors may cause allergic wheezing, and tests can determine which is responsible and what is likely the best approach to treatment.
Anyone who is having difficulty breathing should receive medical attention, and anyone who may be experiencing anaphylactic shock should receive emergency care.