Asthma (Asthmas)

Two Peak Flow Meters[1]

Asthma is a chronic inflammatory disease of the airways characterized by airway hyperresponsiveness and reversible airflow obstruction. It is caused by a combination of incompletely understood environmental and genetic interactions. Common symptoms include wheezing, coughing and dyspnea, which may vary from mild and almost undetectable to severe and unremitting. Symptoms can be prevented by avoiding triggers.


Presentation

Most of the symptoms of asthma involve the respiratory system and symptoms depend mainly on the severity of the condition. Some of the symptoms of asthma are:

Cough: The cough from asthma is so distressing that one find it difficult to sleep. It usually worsens late at night and early in the morning.

Wheezing: Wheezing manifests itself as squeaky or a whistling sound while breathing.

Chest tightness: The patient feels as if something is sitting on the chest and squeezing.

Shortness of breath: Most people find it very difficult to breathe. They feel as if they cannot breathe out.

Symptoms may vary depending on the severity of the condition and if left untreated can even turn fatal. Treatment given at the first onset of symptoms can leave the patient symptomless during the day and night.

Complications

Though not life threatening, asthmatic attacks can affect the regular activities in school and at work and may require frequent hospitalizations. Moreover, it can result in permanent narrowing of the airway. Using long term medications have their own side effects too [10]. Normal asthmatic attacks if not taken proper care can turn out to be life threatening condition called the status asthmaticus that may require hospitalization.

Workup

The diagnosis of asthma is usually done by assessing the patient’s condition, by doing a complete physical examination, undertaking a thorough medical history and by doing lung function tests.

Obstruction of the airflow is assessed and proper examination is done, if the obstruction is at least partially reversible [1].

Wheezing is assessed using a stethoscope and the obstruction is considered reversible if the wheeze disappears with treatment or if the triggering factor is resolved. Various physiological tests are done to assess lung function. Some of them are:

  • Spirometry
  • Peak flow meter
  • Bronchial provocation

Apart, from these various other tests are done to exclude other possible diseases. Some of such tests are, X-ray of the chest and sinuses, testing for allergies and evaluation for gastroesophageal reflux diseases [3]. These can act as triggering factors and can worsen the asthmatic condition and hence assessment of possibilities for such worsening conditions is absolutely crucial.

Treatment

Treatment involves keeping the symptoms under control by using proper medications. The breathing pattern should be tracked often to assess the efficacy of the medication. In case of occasional flare-ups, inhalers such as albuterol are used for symptomatic relief. The choice of various medications used in the treatment of asthma are based on the patient’s age, symptoms, triggers and effectiveness [6]. Medications for asthma are of three categories.

Preventive, Long term medications

They reduce the inflammation of the airways leading to symptoms. Some of such medications are:

  • Inhaled corticosteroids- E.g. Fluticasone, budesonide
  • Leukotriene modifiers – e.g. Motelukast, zafirlukast
  • Long acting beta agonist – e.g. Salmeterol, Formoterol
  • Combination inhalers- e.g. Fluticasone- salmeterol, budesonide-Formoterol
  • Theophylline

Quick relief inhalers 

They open up the swollen airway and hence ease breathing. Some of such medications are:

  • Short acting beta agonists
  • Ipratropium
  • Oral and intravenous corticosteroids

Allergy medications such as antihistamines and decongestants if necessary [9].

Prognosis

Asthma is a chronic disease and prognosis usually depends on the severity of the disease. In some cases the disease can go into longer periods of remission. Generally in mild to moderate cases, the symptoms can improve over time and in some adults, they can even be disease free. Even when it comes to some severe cases, adults may find good improvement depending on the timeliness, the effectiveness of the treatment and the degree of lung obstruction.

Only in about 10% of the cases the condition is very severe and persistent and not responsive to treatment [7]. There is an irreversible decline in lung function in such patients and there are also changes in the walls of the airways which are progressive.

Smoking exacerbates the condition and declination in lung function is much faster in people with asthma than normal individuals. Death as a result of asthmatic attacks is relatively rare and can be prevented by proper medications. Though this disease condition is not that debilitating, it can turn out to be a hindrance to day-to-day activities and work if not properly controlled.

Etiology

The etiology for the occurrence of asthma has not yet been completely established. The link between the genetic and the environmental factors in the occurrence of asthma is still a subject of debate and studies are being carried on to establish the relationship of allergy to asthma. Exposure to infections and endotoxins in infancy or early childhood may act as risk factors depending on the timing of exposure.

Prenatal exposure to maternal smoking has been strongly associated with the incidence of asthma. Moreover, stress, diet, nutrition, mode of delivery and use of antibiotics are also associated with the occurrence of asthma. In later stages of life, exposure to allergens, gender, sex, family size and structure, occupational exposure to allergens are all considered to be predisposing factors to asthma.

Epidemiology

Most of the cross-sectional studies that are population based are dependent mostly on recognizing the symptoms. There is a wide variation on documentation of prevalence of asthma.

Documented evidence suggests low prevalence rate of asthma in Asian countries like China and India. There is only a 2-4% of prevalence in these countries when compared to developed countries such as the United Kingdom, Canada, Australia and New Zealand, the prevalence of this disease is documented to be 15-20%.

Sex distribution
Age distribution

Pathophysiology

The pathophysiology of asthma is a complex phenomena and the attack may be spontaneous or it may be triggered. Either way, the attack progresses as follows.

  • Initially there is an activation of the inflammatory cells resulting in the release of inflammatory mediators from the epithelial cells, macrophages and the bronchial mast cells.
  • There is an increased responsiveness in the airway smooth muscles as a result of alterations in the neural control of the muscle tone and disturbance in the epithelial integrity.
  • This results in clinical manifestations such as dyspnea and wheezing.

The various factors that contribute for the clinical manifestations are, bronchospasms, edema and inflammation of the mucosa, thick mucus that contributes to airway obstruction, hyperinflation, impaired gas exchange and increased work on breathing [4]. If the initial attack is not taken good care the condition may exacerbate into a more acute and severe form called the status asthmaticus which may require hospitalization.

Prevention

Asthmatic attacks can be prevented by reducing the exposure to the triggers. For this the first step is to identify the triggers. Some of such triggers include air pollution, allergies, sinusitis, cold air, flu virus, smoke and fragrances. Maintaining a diary of conditions that can trigger an asthmatic attack can be helpful in managing the symptoms.

An IgE testing can also be done to identify substances that can sensitize and induce an asthmatic attack. For some people exercise may induce an asthmatic attack and such people should consult their physician before undergoing an exercise regimen [2].

Smoking can worsen the asthmatic attack and hence smoking in any form such as smoking tobacco, fireworks, incense and candles should be avoided.

If cold and flu can induce an asthmatic attack, avoiding situations that can cause a cold or flu such as a crowded place or exposure to cold air must be avoided to reduce the incidence of asthmatic attacks [5].

Summary

Asthma is a chronic inflammatory disease found worldwide. This disease affects the airways and is characterized by a reversible bronchospasm and airflow obstruction. It has been estimated that 24 million people are affected by this disease and being a common childhood disease, more than 7 million children are found to be victims of this disease.

The occurrence of asthma has increased over the recent years especially after the 1970s. Asthma has also been found to be a cause for around 250,000 deaths. The etiology for the occurrence of asthma is a bit complex and involves a combination of genetic and environmental factors.

Patient Information

Asthma is a chronic illness that can be managed successfully with proper medications. Though an asthmatic attack turning to become fatal is rare, it can be debilitating at times affecting day-to-day life. Hence it is necessary to keep note on the triggering factors by maintaining a diary and avoiding them [8]. Usage of proper medications prescribed by the physician are mandatory to avoid future asthmatic attacks and avoiding flare ups.

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References

1. Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma-Summary Report 2007. J Allergy Clin Immunol. Nov 2007;120(5 Suppl):S94-138.

2. National Heart, Lung, and Blood Institute. Global Strategy for Asthma Management and Prevention. NIH Publication; 2008.

3. Harding SM, Guzzo MR, Richter JE. The prevalence of gastroesophageal reflux in asthma patients without reflux symptoms. Am J Respir Crit Care Med. Jul 2000;162(1):34-9.

4. Randolph C. Exercise-induced asthma: update on pathophysiology, clinical diagnosis, and treatment. Curr Probl Pediatr. Feb 1997;27(2):53-77

5. Bateman ED, Hurd SS, Barnes PJ, Bousquet J, Drazen JM, FitzGerald M, et al. Global strategy for asthma management and prevention: GINA executive summary. Eur Respir J. Jan 2008;31(1):143-78.

6. Management of Asthma Working Group. VA/DoD clinical practice guideline for management of asthma in children and adults. Washington (DC): Department of Veteran Affairs, Department of Defense; 2009

7. Moorman JE, Rudd RA, Johnson CA, King M, Minor P, Bailey C, et al. National surveillance for asthma--United States, 1980-2004. MMWR Surveill Summ. Oct 19 2007;56(8):1-54.

8. Kotses H, Bernstein IL, Bernstein DI, Reynolds RV, Korbee L, Wigal JK, et al. A self-management program for adult asthma. Part I: Development and evaluation. J Allergy Clin Immunol. Feb 1995;95(2):529-40.

9. From the Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA) 2010. Available at http://www.ginasthma.org.

10. Sears MR. Consequences of long-term inflammation. The natural history of asthma. Clin Chest Med. Jun 2000;21(2):315-29.

Media References

  1. Two Peak Flow Meters, Public Domain

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