Allergy and Asthma: Why Do They Often Occur Together?

Allergy triggered asthma is most common form of asthma

Woman with allergy triggered asthma sneezes into tissue.

Allergy triggered asthma is most common form of asthma

Pollen. Dust mites. Pet dander. For people with asthma, these allergens may trigger an asthma attack. Allergy induced asthma is the most common type of asthma in the United States.


More than half of adults with asthma, and 80 percent of children with asthma have allergic reactions to such everyday things like pollen, dust, mold spores and pet dander.


Asthma symptoms may also be caused by non-allergens, such as exposure to tobacco smoke. Identifying underlying allergies and other triggers is important for treatment to keep it under control and prevent asthma attacks.


“Your doctor may take a detailed medical history, review symptoms, do a physical exam and do breathing tests and possibly order blood, allergy or other tests,” says Katharine Woessner, MD, an allergist and immunologist at Scripps Clinic.

What is asthma?

Asthma is a respiratory condition that affects the airways of the lungs and interferes with normal breathing. An asthma attack is often marked by shortness of breath, coughing and wheezing.


An asthma attack happens when asthma triggers irritate the airways and cause the immune system to overreact.

What is an asthma attack?

During an asthma attack, three things happen:


  • The airways become inflamed and swollen.
  • The muscles around them constrict and make the airways even smaller.
  • The mucous glands in the airways step up production, further blocking the opening, making it difficult for air to pass freely to and from the lungs.

Symptoms of allergies and asthma

Allergies can either worsen asthma or trigger it. Both conditions can cause respiratory symptoms, such as coughing and congestion.


Some symptoms are unique to each disease.


Allergies may cause:


  • Watery and itchy eyes
  • Sneezing
  • Runny nose
  • Scratchy throat
  • Rashes and hives


Asthma usually does not cause these symptoms. Instead someone with asthma more often experience:


  • Chest tightness
  • Wheezing
  • Breathlessness
  • Coughing at night or in the early morning.


For some asthma sufferers, an asthma attack can mean a life-threatening inability to breathe at all. Without treatment, asthma attacks can kill, not just because fresh air can’t get in, but because carbon dioxide buildup in the lungs can’t get out.


“Never ignore possible signs of asthma, downplay its severity or try to treat symptoms yourself with over-the-counter medications. Remember, left untreated, asthma can be fatal. Always consult with your doctor,” Dr. Woessner says.

What causes allergic asthma?

In an allergic asthma attack, the immune system overreacts to an offending allergen by releasing a number of mediators and chemicals that trigger the symptoms of an allergy attack and asthma.

Other causes of asthma

Asthma also may be triggered by environmental factors, such as cigarette smoke, perfumes, foods, even changes in the weather. Lifestyle may play a role. Some attacks are brought on by exercise, illness, strong emotions, or stress. Most people with asthma can have symptoms triggered by a number of stimuli.

Infants, children and asthma

Asthma runs in families, so if both parents have asthma, a child’s chance of getting it is over 60 percent. It affects boys more often than girls, although it evens out around puberty.


Signs of asthma in children and infants may include rapid breathing, wheezing, breathlessness, coughing after running or other activity, nighttime cough, frequent respiratory infections and a chest that appears caved in.


It’s a myth that children outgrow their asthma. Lungs remain sensitive for a lifetime. Symptoms may go away as lungs grow and create more room for air flow. Symptoms may reappear later in life. Some people who develop asthma after age 20 may have had it as a child and not been aware of it.

Medication for allergies and asthma

Most treatments target either asthma or allergies. Some methods specifically treat symptoms related to allergic asthma. It is important to control the allergies in order to gain control of you asthma.


Asthma can also be helped through medication:


  • Bronchodilators help relax constricted muscles to let air flow through to the lungs.
  • Anti-inflammatories tame the airways’ reaction to triggers and keep them from swelling.
  • Leukotriene modifiers help ward off the chemicals that cause airways to swell and tighten and help halt the production of mucous.


For people with severe asthma, there are several new treatments that will help to get it under control and prevent a visit to the emergency room and hospital.


“If you have asthma, your doctor can recommend the best medication for you,” Dr. Woessner says.

Living with asthma

Ask your doctor for a written treatment plan that tells you how to manage your asthma both day-to-day and in emergencies. Many people find that a solid, written guide to working, exercising, sleeping and enjoying life with asthma enables them to feel in control of their condition and makes their everyday lives easier.

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