Asthma is a chronic inflammatory condition that affects more people worldwide than there are people in the United States: a staggering 300 million. While the underlying cause is unknown, its symptoms have allowed us to understand the physiology of asthma.
Interestingly, the physiology of asthma is almost identical to that of allergies. In fact, most of the time, an asthma attack – that is, an acute episode of symptoms – is triggered by a common allergen, such as pollen, mold, or even food.
The Allergic Reaction
Even with all the recent developments in immunology (AIDS, for instance), allergies remain a mystery to the scientific world. We understand how they happen, but not why they happen.
Definition
An allergen is anything that causes the immune system to react unnecessarily. Normally, the immune system works to keep anything out of the body that doesn’t belong there – like the influenza virus or a sliver. Through a series of powerful reactions, the immune system causes helpful cells and proteins to rush to a site of infection, isolating and destroying the unwanted intruders. You can see and feel your immune system doing just this, like when your tonsils become swollen and painful when you have a bad cold, or when a scrape oozes with clear liquid.
Search and Destroy
But sometimes the immune system reacts unnecessarily. Things that wouldn’t normally be harmful to the average person – like dust or mold – can trigger a miserable state in someone with allergies. Instead of ignoring these harmless substances, the immune system recognizes them as foreign and does what it normally does to rid the body of unwanted things: sends fluid containing cells and proteins to the site of entry. The fluid involved in an allergic reaction can cause things to swell, while the proteins can cause reactions like sneezing or coughing. In all of these actions, the immune system is trying to clear the body of invaders.
Asthma
When someone has asthma, they often experience similar symptoms in reaction to harmless substances. The symptoms of asthma, however, are localized to the respiratory system. In response to a trigger like pollen or pet dander, the immune system of an asthmatic will respond by causing the muscles of airways to contract. Cells within the respiratory system are instructed to produce more mucus in an effort to trap the supposedly harmful particles. An excessive amount of fluid rushes to respiratory tissues causing the airways to swell, limiting the entry of foreign substances (and air). An asthma attack is essentially an allergic reaction that is localized to the respiratory system.
Similarities in Treatment and Prevention
Because the immune system is responsible for the symptoms experienced in both an asthma attack and an allergic reaction, the treatment required is often the same. Chemicals like antihistamine reduce inflammation, while bronchodilators relax contracted muscles of the airways.
It may seem as though we would be better off without an immune system considering the harm of which is it capable. This notion can be quickly crushed, however, when considering the mortality rate of AIDS patients, who essentially have no immune system.
Although the immune system is a powerful, and in some cases deadly, entity, without it we wouldn’t survive long. Instead, we must attempt to keep it in check while dealing with the irritation it can invoke in allergies and asthma.
