Allergic Cough: Causes, Symptoms, Diagnosis, Treatment, and Prevention
Some coughs are caused by allergic reactions to substances in the environment, such as pollen, dust, pet dander, or mold. This type of cough is called an allergic cough.
An allergic cough often seems like a barking or hacking cough. An allergic cough is dry and not productive, so it doesn't bring up any mucus or phlegm.
Nevertheless, allergic coughs can also be symptoms of other respiratory conditions, such as asthma and chronic bronchitis. A cough that persists for more than three weeks, produces blood or greenish-yellow mucus, interferes with your sleep or daily activities, or is accompanied by other symptoms such as fever, chest pain, shortness of breath, wheezing, or weight loss should be discussed with your doctor.
Causes of Allergic Cough
An allergic cough occurs when your immune system reacts to a substance (allergen) that it believes to be dangerous but is not. Inflammation and irritation of the airways are caused by the release of histamine and other chemicals by the allergen. Mucus production is increased as a result, leading to postnasal drip.
Some common allergens that can cause an allergic cough are:
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Plants produce pollen during their reproductive cycle, which can be carried by the wind and inhaled by people with pollen allergies.
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Inhaling dust can trigger a reaction in some people who are allergic to soil particles, pollen grains, animal dander (dead skin cells), mold spores (fungi), and other substances that accumulate on surfaces.
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As pets shed skin flakes, pet dander can stick to carpets, furniture, bedding, and clothing and become airborne when disturbed or cleaned.
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Inhaling mold spores can cause an allergic reaction in some people. Mold grows in damp places like basements, bathrooms, kitchens, and outdoors.
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In addition to pollen and weeds, some people may be allergic to animal hair, food additives, medications, insect stings, tobacco smoke, chemicals, metals, latex, perfume, etc.
Symptoms of Allergic Cough
The main symptom of an allergic cough is a dry and non-productive cough that may sound like a barking or hacking noise. The cough may be worse at night when lying down due to postnasal drip.
Other symptoms that may accompany an allergic cough are:
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Runny nose
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Nasal congestion
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Sneezing
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Itchy eyes
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Watery eyes
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Red eyes
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Throat irritation
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Hoarseness
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Fatigue
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Sinus headache
Diagnosis of Allergic Cough
It is important to discuss your medical history, symptoms, and exposure to potential allergens with your doctor in order to diagnose an allergic cough caused by an allergy exposure. They will also perform a physical exam, including checking your ears, nose, throat, and lungs for signs of infection, inflammation, or obstruction. Tests may also be ordered, such as:
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As part of the skin prick test, a needle is used to inject small amounts of different allergens into your arm. If you develop any redness or swelling at the site where the allergens were applied, another needle will be prickted at 15 minutes to determine if you are allergic to them.
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During a blood test, a sample of your blood is taken from your vein and sent to a laboratory to be analyzed. Your blood will be tested for antibodies called immunoglobulin E (IgE) that react to specific allergens.
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The challenge test involves being exposed to increasing doses of an allergen under controlled conditions while having your breathing monitored by spirometry(a device that measures how much air you can inhale and exhale). This test can confirm if you have an allergy to that substance.
Treatment of Allergic Cough
Some of the treatment options for allergic cough depend on the cause and severity of the condition. The main goals of treatment are to relieve symptoms, reduce exposure to the allergen, and prevent complications.
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Antihistamines: These medications block the effects of histamine, the chemical that causes an allergic reaction. They can reduce coughing, sneezing, runny noses, and itching. Antihistamines include diphenhydramine (Benadryl), loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra).
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Decongestants: These medications shrink the swollen blood vessels and tissues in the nose and sinuses. Decongestants can relieve nasal congestion and sinus pressure. Some examples of decongestants include pseudoephedrine (Sudafed), phenylephrine (Neo-Synephrine), and oxymetazoline (Afrin).
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Dextromethorphan (Robitussin), codeine, and hydrocodone are examples of cough suppressants. Cough suppressants reduce the urge to cough by affecting the cough center in the brain.
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Guaifenesin (Mucinex) and acetylcysteine (Mucomyst) are examples of expectorants that thin mucus, making it easier to cough up.
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Inflammation, congestion, and mucus production can be reduced with nasal sprays because the active ingredient is directly delivered to the nasal passages. Among the nasal sprays are saline (salt water), corticosteroids (such as fluticasone and budesonide), antihistamines (such as azelastine and olopatadine), and mast cell stabilizers (such as cromolyn).
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With an inhaler, medication is delivered to the lungs via a mouthpiece or mask. Inhalers help relax the muscles around the airways, reducing coughing, wheezing, and shortness of breath. Bronchodilators (such as albuterol and salmeterol) and corticosteroids (such as fluticasone and budesonide) are examples of inhalers.
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A treatment called immunotherapy involves gradually desensitizing the immune system and reducing the allergic response by exposing the body to small amounts of the allergen over time. The allergic cough and other symptoms can be treated with immunotherapy, either as a shot (subcutaneous immunotherapy) or as a tablet or drop under the tongue (sublingual immunotherapy).
Prevention of Allergic Cough
An allergic cough can be prevented by avoiding or minimizing exposure to the allergen that causes it. Some strategies include:
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Keep a diary of your symptoms and the possible triggers, do an allergy test, and read the labels of the products you use to identify and avoid the allergen. If you want to improve the air quality at home or at work, you can also use a humidifier, a dehumidifier, or an air purifier.
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Wear protective gear: Wear a mask, gloves, goggles, or a hat when you are exposed to the allergen, such as when you are cleaning, gardening, or working outside.
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You can take an antihistamine, a decongestant, or a nasal spray before you encounter the allergen, such as when traveling, visiting a friend with a pet, or visiting a high pollen area.
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Treat your allergic cough and other respiratory conditions, such as asthma or chronic bronchitis, according to your doctor's recommendations.
