Respiratory Therapist/About allergy related cough
QUESTION: I have ongoing cough after cold. I am pretty sure it is related with the allergy because the cough can be immediately controlled by taking the antihistamine medicine such as Loratadine or Zyrtec. If I stop the antihistamine, the cough will return. I searched it online and saw it may be called allergic cough. However, when I travelled abroad and saw a doctor, I was told I have allergic bronchitis because the doctor heard a wheezing sound when I deeply breathe. I wonder whether the allergic cough and allergic bronchitis are the same. What is the standard medical term for this kind of disease? Is the treatment the same for the allergic cough and allergic bronchitis? Can you explain it? Thank you.
ANSWER: Hi Ray,
Allergic cough is used more as a generic term descriptive of a cough that
is produced in response to an allergic reaction. The term may be more
likely to be used where cough is the main symptom of a known allergy, or
where there is no other identifiable cause and allergy is suspected.
Allergic bronchitis is also produced in response to an allergic reaction but it is a
condition, which can be classified as a form of chronic bronchitis, that involves
a number of adverse effects and symptoms including allergy-induced (allergic)cough.
The allergic response over-activates the immune system by release of histamine and other
inflammatory mediators that act to initiate the adverse effects and symptoms often
seen in allergic bronchitis such as cough, runny nose, bronchoconstriction
and mucus production that may produce wheezing,shortness of breath, and other
symptoms. In contrast,acute bronchitis, which has similar symptoms, is not
allergy related but instead is most often triggered by a cold, or viral or bacterial infection.
It is has been shown that elevated levels of histamine induced in an
allergic response activate processes which increase cough sensitivity that
can lead to chronic cough. Anti-histamines can block histamine action and
thereby reduce the cough sensitivity and thus the coughing. So,histamine
may not directly cause the cough but lowers the cough threshold,
predisposing a person to cough on exposure to agents that might not
otherwise produce a cough. Under such circumstances it is more likely that
cough frequency will increase adding to airway inflammatory and irritant
stresses that promote further coughing, and prolong healing. The cough may persist
for a month or so.
Since anti-histamines can block the action of histamine which may increase
coughing then taking anti-histamines may improve persistent coughing and can also
be beneficial, at least to a degree, in histamine-induced symptoms in allergic
bronchitis such as bronchoconstriction, mucus production and cough. If some
symptoms are not related to histamine-induced mechanisms they will probably
not respond to anti-histamine dosing. In fact, cough sensitivity can also be
regulated by other inflammatory mediators which could dampen the positive
effect of anti-histamine on cough in some cases. And, not all anti-histamines
are created equal so effectiveness may vary. But, from what you said, taking
anti-histamine such as loratadine, works to relieve your cough; so, as
they say, it is hard to argue with success. However, if you suspect that
you are allergic to something in your environment that may be related to
your cough, or is making it worse, this needs to be addressed in order to
prevent the likelihood of repeat episodes and long-term problems. If your
cough persists for more than a month, or worsens, it might be wise to
schedule an appointment with your doctor to be sure there are not other
more serious underlying problems.
If you need further clarification please let me know and I hope you will be
cough-free and feeling well soon.
---------- FOLLOW-UP ----------
QUESTION: I knew what my problem is but do not know how to accurately tell a doctor the medical term of my disease. Should I say I have allergic cough or allergic bronchitis? So I still need to further ask you whether the treatment is the same if one doctor says I have allergic cough while another doctor says I have allergic bronchitis. So far, I only noticed the allergic cough seems prescription of the oral antihistamine medication while the allergic bronchitis frequently prescripts the antihistamine medication AND inhalers. Can you further explain the difference in the treatment between the allergic cough and allergic bronchitis or tell the reader the treatment is the same, prescription of the antihistamine is the main choice? Thank you for your answer.
I do not know the circumstances of either case so I can only guess that each doctor based his/her diagnosis on observation of your symptoms, physical assessment and what you told them. Either you had symptoms of allergy or you gave some information that suggested they were allergy related or both. You said you had a wheeze in one instance and this along with other symptoms may have led the doctor to conclude it was bronchitis related to allergy. Perhaps in the first case you primarily had a cough and no wheeze or other symptom that would warrant a different diagnosis. Sometimes cough may be only complaint in a bout of bronchitis. I do not really have any information to work with so I cannot clarify this for you.
If you are concerned about exactly what the diagnosis of allergic cough means perhaps you could call the doctor you saw and ask him/her to clarify for you, then you could know for sure.
If you are planning to see another doctor about your cough it is best just to explain to the doctor what the previous doctor(s) told you (i.e. I was told I have allergic bronchitis) along with your symptoms, history and physical assessment, he or she should be able to make the proper determination from there. I do not know your history or any other symptoms you may have,like shortness of breath, wheezing etc. You have only mentioned that you have a persistent cough after a cold, so I do not know if is dry or productive, if you have pain with it, how long you have had the problem currently, how frequently it occurs, if you have any idea what triggers it, or how long bouts last, if the symptoms are the same each time and how severe they are. These are all things a doctor will need to know to determine the real nature and extent of your problem,in order to determine appropriate testing if needed (i.e allergy, etc), and to assure proper diagnosis and treatment.
The treatment in either case is generally symptom based. If you only have a cough and the anti-histamine takes care of the cough then that is generally the only treatment required. Cough suppressants are used more commonly when allergy is not involved. If there is significant inflammation associated with the cough steroids may also be given. The most important thing, as I stated previously, is to determine what is triggering the reaction and try to prevent exposure. For instance you may have cigarette smoke, mold, dust, air fresheners, etc. in you house, or fumes or chemicals at work, etc. If you smoke or are around cigarette smoke frequently this can make your situation much worse as this is the number one exposure factor leading to chronic bronchitis. No medicines will be as effective as prevention.
If you have symptoms other than cough, like wheezing, tight chest, thick mucus production, inflamed and irritated airways, then other medications may be required. Frequent or periodic wheezing can be treated with bronchodilators either as an inhaler or a nebulizer (i.e. albuterol or Duoneb) as needed. Bronchodilators help to open constricted airways which relieve wheezing and make breathing easier and make it easier to remove mucus, if present, by coughing. And sometimes steroids, which may be inhaled, are used to help treat inflammation of the airways, if warranted. It is best to try to prevent getting to the point that you need these medications if possible.
I hope this answers your questions more thoroughly and that you are able to resolve your health problems soon.