Allergic cough is defined as cough caused by allergy rather than an infection. Cough is one of the most common signs and symptoms of diseases both in adults and children, from a common and transient respiratory tract infection as the common cold to more serious and chronic illnesses which can even be life-threatening.
In this article, we will discuss cough developing due to allergic disease such as allergic rhinitis, commonly known as hay fever.
Symptoms of Allergic Cough and differences with a common cold
Allergic cough is caused by an excessive response from the immune system to some substances, such as dust and pollen, known as allergens; being mistakenly recognized by the organism as germs, the immune systems attacks such allergens and releases chemical substances like histamine which cause the classic allergy symptoms.
Symptoms associated with allergies are:
- Red, itchy and watery eyes
- Runny or stuffy nose
Other possible symptoms are fatigue, headache and sore throat.
These symptoms are similar to those experienced with a common cold, but their characteristics are very different.
Allergic symptoms last from days to months depending on how long you are exposed to the allergen. If you are allergic to cats and are briefly in contact with one, those symptoms may last just a couple of hours. If you are allergic to pollen, your symptoms may last for several months from the onset of symptoms to when the plants stop releasing their pollen. Allergic symptoms can happen any time of the year and in some cases, like pollen allergy, they are seasonal and happen around the same time every year. Another characteristic of allergy symptoms is that the onset of such symptoms is very rapid after contact with the allergen.
Symptoms from a viral infection tend to last between 3 and 14 days and are more likely to be experienced in winter although they are possible any time of the year. After catching a virus, it usually takes a couple of days for the symptoms to appear and the onset is more gradual. With a cold or other viral infection, you may also experience fever and aches which are not a symptom of allergies.
Persistent cough: is it CoViD-19 or allergy?
Due to the current pandemic, some may wonder whether their cough is simply a seasonal allergy or a symptom of coronavirus disease 2019 (CoViD-19). According to the CDC, the following are the symptoms of coronavirus which appear 2-14 days after exposure:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
Some of these symptoms clearly differentiate between COVID and allergies, such as fever which is the main symptom, loss of taste and smell, nausea and vomiting, and diarrhea. These symptoms may range from mild to severe and you may only experience some of those.
COVID-19 does not respond to allergy medications, so if you feel better after taking your usual allergy treatment you likely don’t have an infection.
If you have some of the above symptoms don’t panic, it could also be another type of infection unrelated to the outbreak.
Difficulty breathing and/or shortness of breath are also common with asthma that can worsen during allergy season.
Symptoms should always be looked at critically, logically and as a whole, so calling your GP for a consult is always a good choice.
Trouble breathing, persistent pain or pressure to the chest, confusion, inability to wake or stay awake, bluish lips or face, are all emergency warning signs according to the CDC so if you or someone you know is experiencing such symptoms call the medical emergency number. The list does not cover all possible symptoms so for any severe or concerning symptom you should call your medical provider.
Allergic bronchitis vs acute bronchitis
Bronchitis may be caused by allergies or by an infection and its main symptom is coughing. Germs are the of cause acute bronchitis, which usually lasts from a few days to a few weeks; conversely, chronic allergic bronchitis may last several weeks or months.
With bronchitis there is also mucus production, which is clear or whitish when it’s chronic or due to allergies, while it is green or yellow when it is due to an infection. Moreover, acute bronchitis generally causes fever too, which is not present in chronic or allergic bronchitis.
Chronic allergic bronchitis may be caused by the exposure to allergens like pollen and dust, and may worsen with pollution; chronic cough may also have other causes.
Other possible causes of chronic cough
A chronic cough may be a sign of a wide range of illnesses and diseases. Some of the most common are:
- Allergic rhinitis
- Chronic rhinosinusitis
- Acid reflux
- Some medications such as ACE-inhibitors for blood pressure
- Primary lung disease
- Other causes
You should refer to your GP for a proper evaluation and differential diagnosis of your chronic cough.
Why do allergies cause coughing – Throat itching and cough
Allergic cough is usually caused by swelling or irritation of the airways. Irritation if often caused by what is known as postnasal drip: nasal secretions due to the allergy drip down the throat causing irritation of both the throat and the larynx and a tickling feeling which in turn causes the cough. Although allergies are usually worse during the day when it is more likely to be in contact with allergens, postnasal drip may be worse at night due to the position of the body: by lying down, due to gravity and the anatomy of the nose, it’s easier for liquids to drip into the throat and cause the itching.
Allergic cough in children
Cough as a symptom accounts for roughly 10% of all medical appointments in patients younger than 15 years old, with most cases being self-resolving and classified as acute cough due to upper respiratory tract viral infection. If a cough lasts more than 3 weeks or if episodes of cough are recurring over several months, it is advised to seek a proper evaluation by a medical professional.
Allergic cough in children is caused by post-nasal drip and upper airways irritation by the allergens.
Allergies tend to run in families: If both parents have allergies, the children have a 60-70% chance of being allergic too, while if only one parent has allergies, the chance is lower, around 30%. The exception to this is allergies to medications, insect venom and latex.
Allergic cough treatments and remedies
There are several remedies as well as treatments available OTC for allergic cough.
The first thing to do is to understand what substance is causing the allergy. Seasonal allergies are commonly triggered by grass pollen, ragweed pollen, spores from molds and fungi, and tree pollen. Year-round allergies are commonly triggered by dust, mites, pet hair or dander, and mold. Your doctor may order a Skin Prick Test (SPT) or a Specific IgE Blood Test to find out what you’re allergic to.
Once the allergen is known, you should avoid it. You may want to keep the windows closed during allergy season both at home and in your car, take a shower and change your clothes after spending time outdoor, and get an air purifier or making sure your air conditioning system has a clean filter. Face masks with filters are also an option when being outdoors. You can also check your local pollen counts online and avoid going out during peaks.
Other remedies for allergic cough are:
- Nasal sinus irrigations (nasal rinse) with saline solution, which can wash out any irritant stuck in the nose and curb nasal drip.
- Drinking warm water mixed with honey and lemon may help soothe the throat and reduce the need of coughing. Honey by itself (1-2 teaspoons) may also help relieve your cough.
- Nasal corticosteroids
- Eye drops for red, itchy, watery eyes. This is because tears are drained through the tear duct to your nose and may contribute to postnasal drip.
- Oral and nasal antihistamines
- Nasal decongestants
- Leukotriene inhibitors are another class of medications that block chemicals produced by the body in response to allergens. They require a prescription.
- Known as allergy shots, immunotherapy can provide long-lasting symptom relief. It consists of a series of shots with progressively increasing amounts of the allergen to desensitize your organism to it.
Ask your physician for a proper recommendation on the right treatment for your allergic cough.
- Center for Disease Control and Prevention (CDC)
- American Academy of Family Physicians
- American College of Allergy, Asthma and Immunology (ACAAI)
- American Academy of Pediatrics
- Allergy and Asthma – The Basics to Best Practices
M Mahmoudi – Springer, 2019
- Pediatric Allergy – Principles and Practice, 3rd Ed.
DYM Leung, SJ Szefler, FA Bonilla – Elsevier, 2016