Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Asthma in children usually has many causes, or triggers. These triggers may change as a child ages. A child's reaction to a trigger may also change with treatment. Viral infections can increase the likelihood of an asthma attack. Common triggers of asthma include the following:
Respiratory infections: These are usually viral infections. In some patients, other infections with fungi, bacteria, or parasites might be responsible.
Allergens (see below for more information): An allergen is anything in a child's environment that causes an allergic reaction. Allergens can be foods, pet dander, molds, fungi, roach allergens, or dust mites. Allergens can also be seasonal outdoor allergens (for
example, mold spores, pollens, grass, trees).
Irritants: When an irritating substance is inhaled, it can cause an asthmatic response. Tobacco smoke, cold air, chemicals, perfumes, paint odors, hair sprays, and air pollutants are irritants that can cause inflammation in the lungs and result in asthma symptoms.
Weather changes: Asthma attacks can be related to changes in the weather or
the quality of the air. Weather factors such as humidity and temperature can
affect how many allergens and irritants are being carried in the air and inhaled
by your child. Some patients have asthmatic symptoms whenever they are exposed to cold air.
Exercise (see below for more information): In some patients, exercise can trigger asthma. Exactly how exercise triggers asthma is unclear, but it may have to do with heat and water loss and temperature changes as a child heats up during exercise and cools down after exercise.
Emotional factors: Some children can have asthma attacks that are caused or made worse by emotional upsets.
Gastroesophageal reflux disease (GERD): GERD is characterized by the symptom of heartburn. GERD is related to asthma because the presence of small amounts of stomach acid that pass from the stomach through the food pipe (esophagus) into the lungs can irritate the airways. In severe cases of GERD, there may be spillage of small amounts of stomach acid into the airways initiating asthmatic symptoms.
Inflammation of the upper airways (including the nasal passages and the sinuses): Inflammation in the upper airways, which can be caused by allergies, sinus infections, or lung (respiratory) infections, must be treated before asthmatic symptoms can be completely controlled.
Nocturnal asthma: Nighttime asthma is probably caused by multiple factors. Some factors may be related to how breathing changes during sleep, exposure to allergens during and before sleep, or body position during sleep. Furthermore, as a part of biological clock (circadian rhythm), there is reduction in the levels of cortisone produced naturally within the body. This may be a contributing factor for nighttime asthma.
Recent reports of possible association between asthma and acetaminophen use may be due to the fact that children with severe asthma may be more likely to be take acetaminophen for viral or other infections that may actually be due to asthma or may precede an asthma diagnosis.