Can allergies cause a cough?

How allergies cause it

A cough is a spontaneous reflex.⁶ When things such as mucus, germs or dust irritate your throat and airways, your body automatically responds by coughing.⁶

With nasal allergies (rhinitis), your nose may make more mucus.³ When more mucus drains down the back of your throat, substances in it may irritate the throat and cause coughing.³ Allergies like hay fever can cause a chronic dry cough.¹

Allergens are also the most common asthma trigger, and allergic asthma is the most common type of asthma.⁴ Too much of an antibody called IgE can cause swelling of the airways in your lungs, which can make it harder to breathe and set off an asthma flare-up.⁴ In one form, called cough-variant asthma, a chronic cough is the only symptom.² Coughing from asthma can occur after exercise, after exposure to specific triggers or after laughing, and often at night.²

Common triggers of an asthma cough include outdoor allergens, such as pollens from grass, trees and weeds, and indoor allergens, such as pet dander, dust mites and mold.² If your cough is allergy-related, you might notice that you cough more during some seasons or in some environments.¹ In spring, the most common hay fever triggers are tree and grass pollen.⁸ In fall, a common one is ragweed or other weed pollen, or outdoor mold.⁸

Allergies or something else?

Most people have had a cough caused by a cold or flu, the kind that comes on strong for a few days during the illness and then tapers off as you start to feel better.¹ An allergy cough is caused by your immune system’s response to an allergen.¹

Allergy symptoms usually last as long as you’re exposed to the allergen, while colds and flu rarely last beyond 2 weeks.⁷ Fever is not a symptom of allergies.⁹ If you are also wheezing or have tightness in your chest or shortness of breath, you may have an asthma cough.¹

Acute coughs begin suddenly and usually last no more than 2 to 3 weeks, and they are the kind you most often get with a cold, flu or acute bronchitis.⁵ Ninety percent of chronic coughs are related to one of these: asthma, chronic bronchitis, gastroesophageal reflux (GERD), postnasal drip or smoking.¹ Lower respiratory tract infections, which can affect the airways (bronchitis) or go further into the lungs (pneumonia), are more serious viral and bacterial infections that usually cause a deep, lingering cough and fever.⁶

When to see a doctor

A cough that doesn’t go away or comes with other symptoms like shortness of breath, mucus production or bloody phlegm could be the sign of a more serious medical problem.⁶ See a doctor if your cough brings up yellowish-green phlegm or blood.⁶ A cough that comes with other symptoms such as fever, headache, drowsiness or shortness of breath should be brought to a doctor’s attention.⁶ Coughs that make certain sounds, like whooping, wheezing or barking, may also signal a bigger problem.⁶ Any cough that lasts more than 8 weeks should be discussed with your doctor.⁶

If you have a chronic cough that might be related to allergy or asthma, ACAAI says it’s important to get tested.¹ Skin testing is the most commonly used form of allergy testing.¹ If coughing or other asthma symptoms are severe or unpredictable, or flare up more than twice a week, seeing an allergist can help determine their cause.²