Asthma is one of the most common and ancient diseases that our world suffers from . Asthma was recognised as early as Ancient Egypt . But sadly , there is no cure for this epidemic . It usually begins in the childhood . And the statistics related to Asthma are very intimidating .
In 2013, 242 million people globally had asthma up from 183 million in 1990 . It caused about 489,000 deaths in 2013 , most of which occurred in the developing world . The rates of asthma have increased significantly since the 1960s .
So lets start with the definition of this disease …
The word asthma is from the Greek ἅσθμα, asthma which means “panting”.
While asthma is a well-recognized condition, there is not one universal agreed upon definition. It is defined by the Global Initiative for Asthma as “a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. The chronic inflammation is associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing particularly at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction within the lung that is often reversible either spontaneously or with treatment”
According to Wikipedia , It is a common long term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm.
In general , Asthma is a chronic disease involving the airways in the lungs. These airways, or bronchial tubes, allow air to come in and out of the lungs . A person suffering from asthma will always have inflamed airways . They become even more swollen and the muscles around the airways can tighten up when something triggers the symptoms . This makes it difficult for air to move in and out of the lungs, causing symptoms such as coughing, wheezing, shortness of breath and/or chest tightness .
Asthma can also lead to some other health hazards . A number of other health conditions occur more frequently in those with asthma, including gastro-esophageal reflux disease (GERD), rhinosinusitis, and obstructive sleep apnea. Psychological disorders are also more common, with anxiety disorders occurring in between 16–52% and mood disorders in 14–41%. However, it is not known if asthma causes psychological problems or if psychological problems lead to asthma. Those with asthma, especially if it is poorly controlled, are at high risk for radiocontrast reactions .
Asthma is caused by a combination of complex and incompletely understood environmental and genetic interactions .Onset before age 12 is more likely due to genetic influence, while onset after 12 is more likely due to environmental influence. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin and beta blockers. These factors influence both its severity and its responsiveness to treatment. It is believed that the recent increased rates of asthma are due to changing epigenetics (heritable factors other than those related to the DNA sequence) and a changing living environment.
-> Many environmental factors have been associated with asthma’s development and exacerbation including allergens, air pollution, and other environmental chemicals.
-> Low air quality from factors such as traffic pollution or high ozone levels, has been associated with both asthma development and increased asthma severity.
-> Exposure to indoor volatile organic compounds may be a trigger for asthma;for example, formaldehyde exposure. -Also, phthalates in certain types of PVC are associated with asthma in children and adults. Smoking during pregnancy and after delivery is associated with a greater risk of asthma-like symptoms
-> Common indoor allergens include dust mites, cockroaches, animal dander, and mold. Certain viral respiratory infections, such as respiratory syncytial virus and rhinovirus, may increase the risk of developing asthma when acquired as young children. Certain other infections, however, may decrease the risk.
-> There is an association between acetaminophen (paracetamol) use and asthma. Use by a mother during pregnancy is also associated with an increased risk as is psychological stress during pregnancy.
-> The strongest risk factor for developing asthma is a history of atopic disease; with asthma occurring at a much greater rate in those who have either eczema or hay fever.
-> If one identical twin is affected, the probability of the other having the disease is approximately 25%.
-> By the end of 2005, 25 genes had been associated with asthma in six or more separate populations, including GSTM1, IL10, CTLA-4, SPINK5, LTC4S, IL4R and ADAM33, among others. Many of these genes are related to the immune system or modulating inflammation.
-> In 2006 over 100 genes were associated with asthma in one genetic association study alone and more continue to be found.
-> Some genetic variants may only cause asthma when they are combined with specific environmental exposures. An example is a specific single nucleotide polymorphism in the CD14 region and exposure to endotoxin (a bacterial product). Endotoxin exposure can come from several environmental sources including tobacco smoke, dogs, and farms. Risk for asthma, then, is determined by both a person’s genetics and the level of endotoxin exposure.
A person is susceptible to asthma even because of his medical siutuations and his medications.
-> Obesity correlates with asthma , as both of them have risen recently . Several factors may be at play including decreased respiratory function due to a buildup of fat and the fact that adipose tissue leads to a pro-inflammatory state.
-> Beta blocker medications such as propranolol can trigger asthma in those who are susceptible. Cardioselective beta-blockers, however, appear safe in those with mild or moderate disease.
-> Other medications that can cause problems in asthmatics are angiotensin-converting enzyme inhibitors, aspirin, and NSAIDs.
Most individuals can develop severe exacerbation from a number of triggering agents.
-> Home factors that can lead to exacerbation of asthma include dust, animal dander (especially cat and dog hair), cockroach allergens and mold.
-> Perfumes are a common cause of acute attacks in women and children.
-> Both viral and bacterial infections of the upper respiratory tract can worsen the disease.
-> Psychological stress may worsen symptoms—it is thought that stress alters the immune system and thus increases the airway inflammatory response to allergens and irritants
Asthma is classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. It may also be classified as atopic or non-atopic where atopy refers to a predisposition toward developing a type 1 hypersensitivity reaction .
-> Asthma is characterized by recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing.
-> Sputum may be produced from the lung by coughing but is often hard to bring up.
-> Symptoms are usually worse at night and in the early morning or in response to exercise or cold air.
-> Some people with asthma rarely experience symptoms, usually in response to triggers, whereas others may have marked and persistent symptoms.
There is currently no precise test for the diagnosis, which is typically based on the pattern of symptoms and response to therapy over time. A diagnosis of asthma should be suspected if there is a history of recurrent wheezing, coughing or difficulty breathing and these symptoms occur or worsen due to exercise, viral infections, allergens or air pollution.
Spirometry is recommended to aid in diagnosis and management. It is the single best test for asthma. If the FEV1 measured by this technique improves more than 12% following administration of a bronchodilator such as salbutamol, this is supportive of the diagnosis. It is reasonable to perform spirometry every one or two years to follow how well a person’s asthma is controlled.
While there is no cure for asthma, symptoms can typically be improved. A specific, customized plan for proactively monitoring and managing symptoms should be created. This plan should include the reduction of exposure to allergens, testing to assess the severity of symptoms, and the usage of medications. The treatment plan should be written down and advise adjustments to treatment according to changes in symptoms.
The most effective treatment for asthma is identifying triggers, such as cigarette smoke, pets, or aspirin, and eliminating exposure to them. If trigger avoidance is insufficient, the use of medication is recommended. Pharmaceutical drugs are selected based on, among other things, the severity of illness and the frequency of symptoms. Specific medications for asthma are broadly classified into fast-acting and long-acting categories.
Bronchodilators are recommended for short-term relief of symptoms. In those with occasional attacks, no other medication is needed. If mild persistent disease is present (more than two attacks a week), low-dose inhaled corticosteroids or alternatively, an oral leukotriene antagonist or a mast cell stabilizer is recommended. For those who have daily attacks, a higher dose of inhaled corticosteroids is used. In a moderate or severe exacerbation, oral corticosteroids are added to these treatments