An Overview of Allergy Coughs

Learn about symptoms, causes, and treatment of an allergy-related cough

An allergy cough is caused by airborne allergens (allergy-causing substances) like tree and grass pollen, pet dander, dust mites, or mold. These allergens can get into your nasal passages and trigger a hypersensitive reaction.

A cough caused by allergies can be similar to a cough caused by a cold, but they may differ in subtle ways. A cough caused by allergies is usually dry and may feel like an itch or tickle in your throat. Coughs caused by colds tend to be wet and productive, which means you will cough up mucus.

Antihistamines, nasal sprays, and decongestants are a few of the remedies that can help relieve an allergy cough.

Learn more about allergy-related coughs in this article, including the underlying cause and what you can do to relieve them.

Treatment of Allergy Cough - Illustration by Theresa Chiechi

Verywell / Theresa Chiechi

Why Allergies Can Cause a Cough

Cough is a common symptom of seasonal allergies and hay fever. It is caused by your immune system's response to an allergen, rather than by an infection such as a cold or flu. An allergy is essentially the immune system's inappropriate response to a substance that is otherwise harmless.

When exposed to an allergen, the immune system will produce a substance called immunoglobulin E (IgE) that sets off a chain reaction, causing immune cells known as mast cells and basophils to break open and release histamine into the bloodstream.

Histamine is the main cause of allergy symptoms. It causes tiny blood vessels to widen and leak fluid into surrounding tissues. When this occurs in the nose and sinuses, it can lead to nasal congestion and a runny nose.

The cough itself is the result of a postnasal drip. This is when mucus drains from your nose into the back of your throat, causing an itch or tickle that leads to coughing.

What Medications Can Cause an Allergy Cough?

Ironically, some medications used to treat allergies can also cause cough.

Antihistamines are a class of drugs commonly prescribed to treat allergy symptoms. They work by preventing histamine from attaching to cells and triggering inflammation.

Second-generation antihistamines like Claritin (loratadine) and Zyrtec (cetirizine) are able to do this without the drowsiness associated with earlier-generation drugs. However, one of the common side effects of these popular over-the-counter drugs is a cough.

This is because antihistamines have a drying effect that can leave the throat feeling scratchy. Even so, the cough is generally mild and will clear once you stop treatment.

Symptoms of an Allergy Cough

Allergy coughs can sometimes be difficult to differentiate from other conditions like asthma or an upper respiratory tract infection. Generally speaking, however, an allergy-related cough is "dry," meaning that you won't cough up any mucus or phlegm. In some people, the cough can become chronic, lasting for several weeks at a time.

An allergy cough can feel like a persistent tickle or irritation at the back of the throat and is usually accompanied by other allergy symptoms, including:

An allergy can also set off asthma symptoms, triggering cough and other breathing problems. With asthma, you are more likely to experience chest tightness, shortness of breath (known as dyspnea), and wheezing due to the narrowing of the airways of the lungs.

With infections like flu or COVID-19, you are more likely to experience fever, chill, and body or muscle aches. With COVID-19, there may also be a loss of taste or smell as well as nausea, vomiting, or diarrhea.

Signs of an Emergency

An allergy cough may be aggravating but is rarely severe. However, there are situations in which coughing and other breathing problems are a sign of potentially life-threatening, whole-body allergy known as anaphylaxis.

Symptoms of anaphylaxis tend to develop suddenly and severely. If left untreated, anaphylaxis can lead to shock, coma, heart or respiratory failure, and death.

Call 911 or rush you to your nearest emergency room if you experience the following signs and symptoms of anaphylaxis:

  • Shortness of breath
  • Wheezing
  • A sudden outbreak of hives or rash
  • Feeling fainting or lightheaded
  • Sudden, severe diarrhea
  • Nausea or vomiting
  • Rapid or irregular heartbeat
  • Swelling of the face, neck, or throat
  • A feeling of impending doom

How to Treat an Allergy Cough

Oral antihistamines are the first-line treatment for allergy symptoms, blocking the underlying mechanisms that can lead to an allergy cough. Second-generation antihistamines are usually preferred for daytime use because they are less likely to cause drowsiness.

To treat the cough itself, you can consider the following options:

  • Take an over-the-counter expectorant like Mucinex (guaifenesin) to loosen phlegm.
  • Use an over-the-counter decongestant Sudafed (pseudoephedrine) to open nasal passages.
  • Use a nasal steroid spray like Nasacort (triamcinolone) to relieve inflammation and ease breathing,
  • Suck on a cough lozenge, especially ones containing eucalyptus.
  • Use a saline nasal spray or irrigation, like a neti pot, to clear nasal passages.
  • Use a humidifier or vaporizer to help moisturize the air.
  • Inhale steam either with a commercial inhaler or a heated pot of water to loosen mucus and ease throat irritation.

Treating an Allergy Cough at Night

If your allergy cough is keeping you up at night, try taking a first-generation antihistamine like Benadryl (diphenhydramine) before bedtime. The typically undesired side effect of drowsiness can work to your advantage in this case.

When Testing May Be Recommended

Testing by a specialist known as an allergist may be recommended if allergy symptoms are severe and/or are interfering with your quality of life.

The aim of the testing is to determine which allergens you are hypersensitive to. In some cases, allergy shots may be given to gradually desensitize you to those allergens.

The two tests commonly used to diagnose allergies include:

  • Skin prick test: This involves the insertion of tiny amounts of suspected allergens beneath the skin to see if a reaction occurs.
  • Blood tests: These are IgE-specific tests, also known as RAST testing, that can detect antibodies associated with certain allergens. 

An allergist can also help determine if your cough is related to allergic rhinitis (hay fever) or asthma. Identifying the underlying cause is crucial as each of these two conditions is treated differently.

How to Prevent an Allergy Cough

While you can't always avoid respiratory allergies, you can reduce the frequency of them by taking a few precautionary measures.

Among them:

  • Identify and avoid triggers: Start by keeping an allergy diary, taking note of where you were and everything you did up to the time of an allergic reaction. Over time, you may see a pattern emerging and identify which allergens are at the heart of your symptoms.
  • Watch the weather: If you have hay fever, watch local weather reports to see when pollen or mold levels are high. Windy days also increase the amount of allergens in the air, increasing your chances of an allergy attack.
  • Time your activities: During allergy season, pollen levels tend to be higher in the morning. Plan your outdoor activities during the evening if possible.
  • Clean your environment: Allergies to dust and pet dander can be reduced by keeping your environment clean. Replace air filters frequently, and keep pets out of your bedroom. You should also vacuum after your pet has been on rugs or furniture.

Summary

Coughing is a common symptom of seasonal allergies and hay fever. The cough is largely the result of a postnasal drip in which draining mucus irritates the throat.

Allergy coughs can be treated with antihistamines, expectorants, decongestants, nasal irrigation, and steam inhalation. For people with frequent or severe allergies, a visit to an allergist may be advised to help identify the allergens causing your symptoms.

A Word From Verywell

If you are prone to chronic allergies and have to take antihistamines constantly to control your symptoms, it may be time to speak with an allergist.

Allergy shots may be a safe and effective option for reducing your sensitivity to airborne allergens like pollen and pet dander. There are also sublingual (under the tongue) drops and films that are less commonly used but may be helpful if you are averse to shots.

Frequently Asked Questions

  • What does an allergy cough sound like?

    An allergy cough is typically a dry, non-productive cough. The sound of the cough is sometimes described as "barking" or "hacking."

  • How is an allergy cough different from an asthma cough?

    An allergy cough is mainly caused by a postnasal drip that irritates the back of the throat. An asthma cough is induced by the sudden narrowing and spasms of the airways.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  3. Church MK, Church DS. Pharmacology of antihistaminesIndian J Dermatol. 2013;58(3):219-24. doi:10.4103/0019-5154.110832

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By Aubrey Bailey, PT, DPT, CHT
Aubrey Bailey is a physical therapist and professor of anatomy and physiology with over a decade of experience providing in-person and online education for medical personnel and the general public, specializing in the areas of orthopedic injury, neurologic diseases, developmental disorders, and healthy living.