Croup Cough starts when a person acquires a virus (e.g., adenovirus, parainfluenza virus, respiratory syntactical virus) from coming in direct contact with an individual who has the illness. One may get Croup Cough from touching the infected objects and surfaces and then touching his nose or mouth too. The virus will then travel to the sites commonly affected which are the larynx, trachea and bronchial tubes.
As the Croup Cough virus occupies these regions of a person’s airway, the immune system of the body sends in the cellular combatants. These disease fighters are usually the white blood cells (WBC). As the WBC’s battle the foreign microorganisms in the infected tissues, the biochemical reactions occurring will result to inflammation and edema of the airways and surrounding areas.
The swelling may also be caused by one of the body’s defense mechanism. During infectious processes, the body makes the vascular system of the affected areas more permeable for the cellular fragments of WBC. This is for the WBC’s to reach the infection more easily.
Platelets (blood-clotting components) may accumulate in these regions as well to repair the damage caused by the ‘biological warfare’.
The narrowed air passages would then lead to the Croup Cough symptoms of barking cough, inspiratory stridor, voice hoarseness and sternal retractions. All of these signs are due to either the constricted condition of the airways or from the oxygen compensation brought about by the narrowing.
If this upper airway blockage worsens, it can lead to failure of the respiratory system. As the airway is totally obstructed, no air and its oxygen content could be inhaled. This would result to hypoxia or insufficient oxygen level in the body. Serious Croup Cough signs of cyanosis or bluish discoloration will be observed in areas like the mouth of an individual.
Since the airway is also the same path wherein carbon dioxide or ‘used’ oxygen is exhaled, a build-up of this system poisoning substance would result to hypercabia – the condition wherein dangerous levels of carbon dioxide is present in the body. If these severe events of Croup Cough are not resolved immediately, the person will eventually die.