Here’s How Allergies and Asthma Are Linked
The allergy and asthma connection
Each year, more than 50 million Americans experience allergy symptoms, from itchiness to watery eyes and sneezing. For many, however, allergens can also make it difficult to breathe, a condition known as allergic asthma.
Asthma is a respiratory disease that causes the airways to be hyperresponsive or hyperreactive to substances that generally don’t bother other people. For example, when exposed to an allergen, dust, or other triggers, the airways become inflamed and narrow. This can lead to symptoms like coughing, chest tightness, shortness of breath, and wheezing.
It’s one of the most common diseases in the United States today, affecting about one in 13 people.
While things like cigarette smoke, cold air, and exercise can trigger symptoms, for about 60 percent of people with asthma, allergens are a culprit as well.
How are allergies and asthma linked?
An allergic reaction is an immune system response to a foreign substance. If you have an allergy and encounter an otherwise harmless substance—like pollen, dust mites, or pet dander—your body will attack it as if it were a threat.
As part of this protective response, the immune system releases antibodies to fight off the potential danger.
This causes inflammation that triggers typical allergy symptoms, like sneezing and a stuffy nose, explains Ekta Perera, MD, an allergist/immunologist and assistant professor of medicine at Columbia University Irving Medical Center.
But because our upper and lower airways are so interconnected, she says, an allergen’s impact often extends to our lungs.
Just as an allergic reaction can stuff up your sinuses, it can cause the muscles that line your airways to inflame and tighten. This makes it difficult to breathe and can and lead to wheezing, coughing, and shortness of breath—all symptoms of asthma.
What allergens trigger asthma?
According to the Asthma and Allergy Foundation of America (AAFA), the most common allergens that trigger allergic asthma include:
- Dust mites
- Pet hair and dander (skin flakes)
- Pollens, such as tress, grasses, and ragweed
It’s less common for food or chemical allergies to trigger asthma, but some food additives and fumes from paint, cleaning products, or perfumes may worsen symptoms.
Do allergies always cause asthma?
While allergic asthma is the most common form of the disease, not everyone with allergies has asthma—and not all cases of asthma involve allergies.
This inconsistency makes identifying asthma’s cause complex.
“It’s not well understood why some patients have allergic asthma while other patients have different triggers,” Dr. Perera says.
Studies suggest that more than 100 genes may be associated with allergic asthma, so having a family history of asthma might increase a person’s risk.
Dr. Perera says environmental factors could play a strong role, too, like exposure to animals early in life.
There’s overlap between different forms of asthma as well. People with allergic asthma might also experience symptoms from nonallergic triggers like:
- Respiratory infections
- Cold air or humidity
- Smoke and pollution
Do I have allergic asthma?
“Allergic asthma can be under recognized,” says Payel Gupta, MD, an adult and pediatric allergist/immunologist at Mount Sinai Medical Center in New York and cofounder and chief medical officer of the telehealth allergy platform Cleared.
Because any form of asthma can be life-threatening, she says it’s important to recognize the signs to ensure proper treatment.
According to Dr. Perera, the symptoms of allergic asthma are the same as other asthma types. These include:
- Shortness of breath and difficulty breathing
- Wheezing, or a high-pitched whistling sound when you breathe
- Chest tightness
- Coughing, especially at night, when laughing and talking, or during exercise
“If your allergy medications aren’t helping with these symptoms, then it is time to get evaluated and treated for asthma,” Dr. Gupta says.
Does my kid have allergic asthma?
Dr. Noha Polack, a pediatrician with Progressive Pediatrics in New Jersey, explains that kids with allergic asthma often have eczema and chronic nasal congestion in addition to breathing difficulties.
“Kids with asthma [also] always cough. That is the main symptom parents should be on the lookout for,” she says. “Especially a cough that awakens the child from sleep or causes a child to vomit phlegm.”
How is allergic asthma treated?
Allergy medications like antihistamines can help some people with allergic asthma manage their symptoms, Dr. Gupta says. But she explains that in most cases, people need an inhaler like albuterol—a drug that helps open up the lungs quickly—to effectively control their asthma.
Additional treatments are recommended for people who experience more persistent symptoms.
For example, drugs called leukotriene modifiers are often beneficial for treating allergic asthma, Dr. Perera says. These medications work to block the chemicals the immune system releases during an allergic reaction, preventing the inflammation that makes airways tighten up.
Allergy immunotherapy is another treatment that can help with moderate to severe allergy-induced asthma.
Dr. Gupta says this approach comes in two forms: allergy shots or Food and Drug Administration (FDA)-approved sublingual (under-the-tongue) tablets.
“Immunotherapy is a way to desensitize your body from the things that you are allergic to,” she explains. “Over time, your body won’t react as strongly to these allergens, and therefore your symptoms will improve.”
Managing allergic asthma
If you suspect you have allergic asthma, an allergist can confirm the diagnosis.
The doctor will first test how well your lungs are working with a procedure called a spirometry.
During this exam, you may also get a dose of asthma medication or a known asthma trigger so that the doctor can observe how your lung function changes in response.
Once an asthma diagnosis is confirmed, your doctor will work with you to understand what triggers your symptoms. This process can involve:
- Looking at your family medical history
- Testing for specific allergens with a skin or blood allergy test
- Considering your exposure to things like secondhand smoke and pollutants
- Detailing patterns, like if you experience symptoms while exercising or during cold weather
- Making a plan for certain lifestyle changes, like quitting smoking or managing stress levels
Identifying your allergic asthma triggers can help you learn how to limit your exposure and manage your condition.
Research shows that people can lead perfectly normal daily lives when their asthma is well-controlled with professional treatment and trigger avoidance.
Next, learn essential steps you can take to prevent an asthma attack.
- Ekta Perera, MD, allergist/immunologist and assistant professor of medicine at Columbia University Irving Medical Center
- Payel Gupta, MD, allergist/immunologist at Mount Sinai Medical Center in New York and cofounder and chief medical officer for the telehealth allergy platform Cleared
- Noha Polack, MD, board-certified pediatrician at Progressive Pediatrics in New Jersey
- American Lung Association: "Methacholine Challenge Test"
- American Lung Association: "Spirometry"
- Asthma and Allergy Foundation of America: "Allergy Facts and Figures"
- Asthma and Allergy Foundation of America: "Allergens and Allergic Asthma"
- Asthma and Allergy Foundation of America: "Foods Can Affect Asthma"
- U.S. National Library of Medicine: "Allergic asthma"
- The BMJ: "Leukotriene modifiers in the treatment of asthma"
- Scientific Reports: "Effect of asthma control on general health-related quality of life in patients diagnosed with adult-onset asthma"
- Regulatory Toxicology and Pharmacology: "Chemical-induced asthma and the role of clinical, toxicological, exposure and epidemiological research in regulatory and hazard characterization approaches"