subject: Epidemiology And Causes Of Childhood Asthma [print this page] Did you know asthma is the most common chronic disease of childhood? Studies show that asthma affects approximately 5.5 million children under the age of 18 in the U.S.
1 in every 14 school-age kids is diagnosed with asthma sometime during childhood, causing more hospitalizations and Emergency-Room visits than any other condition during these ages.
This fact is especially disturbing, because it has been shown that not only asthma rates haven't decreased in the past 20 year, they have gradually increased. These astounding facts should raise questions regarding the origin of this disease, what causes it and what triggers future attacks or recovery.
Due to the increasing prevalence of the disease, mortality rates have also gone up- in fact they nearly doubled, between the years 1980 and 1995. The exact origin of asthma is not yet known. The physiology and pathology of the disease is known to a certain degree. Children who develop asthma have been found to have more inflammatory cells in their upper and lower airways. These inflammatory cells and mediators activate several processes that take place once one of the airway cells is triggered.
These cells produce and secrete histamine, a mediator that is known to be released during an allergic reaction.Therefore it is thought that asthmatic children are more prone to develop allergies and allergic rhinitis ("hay-fever"). Triggers such as dust, cold wind or physical effort can cause the asthmatic airways to constrict. This constriction is known as airway "hyper-responsiveness". The reason for this reaction is thought to be due to the inflammatory processes within the cells, which lead to contraction of the airway smooth-muscle.
Other irritants and allergens, including viruses, bacteria, plants, animal fur, different scents, etc. can also trigger this inflammatory hyper-response and what is eventually a full blown asthma "attack".
An asthma attack ultimately results in edema and congestion of the airways and increased mucus production in the lungs. These chronic inflammatory responses lead to non-reversible changes in the airway cells (a process called "remodeling"), causing progressive loss of lung and airway function.
This is the reason why asthma is not a simple disease to deal with. Diagnosis and treatment should begin as early as possible, whenever there's even a small suspicion of the disease.
It is easier to make the diagnosis in children with asthmatic family members (parents, siblings), since there is a known obvious genetic connection. It is important to mention that not all children with asthma will grow to have asthma as adults, and sometimes the disease passes after the age of 8-10. The reason to why some undergo regression of the disease is unknown.
