With the dramatic increase of asthma most people know someone with the condition or suffer from the disease themselves.
Scientists are puzzled to way there has been such an increase but there is no denying that more people experience the shortness of breath associated with the condition.
There are several different triggers that can activate an asthma attack. Genes, along with environmental and biologic triggers are the key triggers that affect adults. In children allergies play a higher role, but in recent years it has been suggested that these triggers are impacting adults as well.
Atopy, the allergic process, is a series of events that lead to inflammation of the airways. When the allergen is recognized in the body white blood cells ( TH2-cells) begin to surround the offender. As the cells increase they produce Interleukins 4, 9, and 13 which produce immunoglobulin E. (I) People with both asthma and allergies appear to have a genetic predisposition for overproducing IgE.(/i) During the asthma attack immunoglobulin E antibodies bind to mast cells, which are concentrated in the lungs, skin and mucus membranes. These cells cause spasms in the airways and an overproduction of mucus. Finally at the end of the attack interleukin 5 appears and lingers for several weeks medicating the particles that remain in the lungs.
Asthma can cause irreversible structural and functional changes in the airways over the years a person suffers from it. This remodeling can then cause chronic asthma. Asthma is truly a family affair, with about a third of the sufferers sharing it with another family member. The confusing thing in this case is that even with the familiar background, the patients don’t always have the same causes for an attack.
Female hormones also seem to be a cause. Severity of the conditions can be affected by the menstrual cycle. Women who suffer from asthma can have more severe attacks during any hormonal change. Although it would seem that oral contraceptives would help this it has not proven to be the case. Menopause is not a help either, women’s hospitalizations increase fourfold at this time.
Aspirin can also cause an attack in 10% of the asthmatic population. While aspirin generally helps with inflammation in the asthmatic it has the opposite affect. The attack of an aspirin sensitive asthmatic is often severe and results in up to 25% of asthma hospitalizations.
Asthma is primarily a nocturnal disease, occurring in 75% at that time. Some of the reasons are as follows:
* Chemical and temperature changes in the body during the night that increase inflammation and narrowing of the airways.
* Delayed allergic responses from exposure to allergens during the day.
* The wearing off of inhaled medications toward the early morning.
* An increase in acid reflux (back up of stomach acid) that causes airways to narrow.
* Postnasal drip that occurs during sleep.
* Conditions relating to sleep, such as sleep apnea or sleeping on one’s back, which may worsen any asthma attack that occurs at night.
Another trigger in adult inset asthma are infections, sometime that differs with child induced asthma. Researchers are particularly interested in the organisms Chlamydiapneumoniae, Mycoplasmapneumoniae, adenovirus, and the respiratory syncytial virus. These viruses cause both mild and severe respiratory infections and are looking to be a cause of adult asthma. The common cold itself is assiciated with asthma.
GERD is also a possible factor with about half of adult sufferers having both conditions.
Some theories for the causal connection between GERD and asthma are as follows:
* Acid leaking from the lower esophagus in GERD stimulates the vagus nerves , which run through the gastrointestinal tract. These stimulated nerves in turn trigger the nearby airways in the lung to constrict, which causes asthma symptoms.
* Acid back-up that reaches the mouth may be inhaled into the airways ( aspirated). Here, the acid triggers a reaction in the airways that cause asthma symptoms.
GERD is sometimes hard to detect and might be suspected as a contributor in the following asthmatic patients:
* Those who do not respond to asthma treatments.
* Those whose asthma attacks follow episodes of heartburn.
* Those whose attacks are worse after eating or exercise.
* Those whose coughs follow episodes of acid reflux. (One study found that GERD was associated with about half of the episodes of coughs and wheezes in asthmatic patients.)
Exercise also can be a trigger. Although with exercise induced asthma it is more likely to respond to short acting medicines.