Monday, May 24, 2010

History of Asthma Definitions

As we travel back in time we will learn the definition of asthma has grown through the years.
  • 30,000 B.C.:  Diseases are noted by their symptoms as opposed to their causes.  The symptoms of shortness of breath, wheezing, anxiety, nausea, headache, itchy and watery eyes, runny nose, etc are caused by the unseen spirits and gods.  
  • 10,000 B.C.: Theories started to evolve in most societies that diseases (symptoms) were caused by some kind of imbalance inside the body.  These types of theories would hold strong through most of history.  
  • 5,000 B.C.:  Asthma-like symptoms were described in ancient Egypt, although no respiratory diseases were described. 
  • 2,697 B.C. Chinese physician Ch'i Po provides the first description of asthma (maybe):  "Those who do not rest and whose breathing is noisy have disorders in the region of Yang Ming (the 'sunlight').  The Yang of the foot in descending causes the present disturbance and is ascending it causes the breathing to be noisy."  You can read more by clicking here
  • 800 BC?  The first reference to asthma was made by Homer in his epic poem The Illiad.    "asthma" was derived from the Greek word aazein, which means to exhale with an open mouth or to pant.  Actually, asthma is derived from the Greek word Panos which means panting.  Homer used the term to reference any dyspnea, including shortness of breath after exertion from fighting in a battle. So here asthma was basically an umbrella term that represented all causes of dyspnea (asthma, hay fever, bronchitis, emphysema, kidney failure, heart failure, pneumonia, tuberculosis, etc.)
  • 400 B.C.:  Hippocrates introduced the term asthma into the medical community, using it to describe any medical condition that caused dyspnea.  Pneumonia and tuberculosis are the first two respiratory diseases taken out from under the asthma umbrella.  The cause of asthma was the same as any other disease, it was caused by an imbalance of one of the four humors: Blood, Phlegm, Black Bile, Yellow Bile.
  • 1 A.D.: Celcus was the first to distinguish dyspnea from asthma.  He defined dyspnea as Moderate, unsuffocative breathing without a wheeze (it's chronic); he defined asthma as Vehement breathing that is sonorous and wheezing (it's acute)
  • 100 A.D.: In India, asthma-like symptoms were referred to as Tamaka Swasa, with swasa meaning breathlessness.  It's a condition that closely resembles our modern description of asthma such as wheezing, shortness of breath, increased phlegm and coughing (kawa).  When severe it may result in sweating, trouble lying down and trouble speaking.
  • 100 A.D. Aeretaeus of Cappadocia defines asthma this way: "If a difficulty of breathing is produced either from running, excessive exercise, or any other cause, it is denominated asthma, or any other cause, it is denominated asthma: that disease likwise known by the name orthopnea, is called asthma, because the patients during the paroxysms are affected with difficulty of breathing, it obtains the appelation orthopnea from the patients not being able to breathe easily, unless in an erect posture of body, in a reclining state, there is danger of suffocation taking place." The cause was "coldness of breath with moisture: the matter consists of thick gutinous humors lurking internally." Treatment was based on your age and sex. 
  • 150 A.D.: Galen mostly agreed with Hippocrates that asthma was a humoral disease, and he was the first to define asthma as a disease of wheezing.  He noted that "if the breathing is rough and noisy it indicates that a large amount of thick and sticky humors in the bronchial tubes of the lungs has accumulated and become annoying because it is difficult to expectorate." 
  • 650 A.D.: Paulus Aegineta defines the asthmatic as "those who break thick without fever, like those who have run fast...The affection arises from thick and viscid humours becoming infarcted in the bronchial cells of the lungs... Dyspnea is a common symptom which accompanies these and many other complaints... 
  • 960 A.D.: Haly Abbas, like Galen, refers to asthma as a collection of gross phlegm about the cells in the lungs. His remedies are of an attentuant and incisive nature, and he particularises the vinegar of squills.  He cautious asthmatics to be aware of indigestion, and, therefore, forbids exercise after food, but recommends it before a meal.  After exercise he enjoins hard friction, no doubt with the intention of favouring the cutaneous perspiration
  • 1000:  asthma was a chronic disease in which patients often suffered 'acute paroxysms with similarity of epilepsy and spasm.'  The flow of thick humours from the head to the lungs produced a situation in which 'the patient finds no escape from rapid panting, like the labored panting of one who is being choked or rushed'. 
  • 1180:   Maimonides might have been the first to describe nervous asthma when he wrote how a patient who is "mentally agitated" causes his physical well-being to suffer and eventually he becomes physically ill. He was also to think asthma might be caused by pollutants in the air.  He believed asthma usually began with a cold and advanced to shortness of breath. 
  • 1400:  Korean physicians believed asthma-like symptoms or coughing were caused by excessive eating, fear and shock.
  • 1600: Jean Baptiste Van Helmont was the first to describe asthma as anything other than simply a symptom.  He was the first to propose the idea that asthma was a disease of bronchospasm when he wrote:  "The lungs are contracted or drawn together." He was the first to describe asthma as a nervous disorder. 
  • 1650:  Thomas Willis is actually given credit for the nervous theory of asthma because he wrote more extensively about it. He described asthma as "obstruction of bronchi by thick humors, swelling of their walls and obstruction from without." He describes three types of asthma: 
    • Pneumatic Asthma:  Dyspnea is a result of air passages in the lungs being obstructed or not open enough
    • Convulsive Asthma:  The primary fault of dyspnea comes from the lungs themselves, "in the moving fibres or muscular coats of the air vessels or in the diaphragm and muscles of the chest or in the nerves of the lungs and chest or of the origin of those nerves in the brain."
    • Mixed Asthma:  Both pneumatic and convulsive.
  • 1675:  John Floyer described a hereditary component of asthma, and numerous exacerbating factors such as air pollution, infection, cold air, exercise, sleep, psychological stress, and tobacco smoke, and astutely observed the benefits of clean air and environmental change.  He was the first to separate asthma from other causes of shortness of breath.  You can read more here
  • 1700 Bernardino Ramazzini was the first to describe occupational asthma.  
  • 1750 William Cullen was the first to start removing lung diseases out from under the umbrella of asthma, defining asthma as dyspnea caused by spasp.  He defines asthma as: "Difficult respiration recurring at intervals, with sense of stricture in the breast, respiration performed with a wheezing noise; difficult cough at the beginning of the fit, sometimes none, free towards the end; and often with copious discharge of mucus."
  • 1800:  Robert Bree believed asthma was a humoral disease and not a spasmotic disease.  He believed that some sort of paroxysm was present in the air tubes that caused asthma.  As the asthma fit progressed, the asthmatic would ultimately cough up some sputum, and with the sputum would be expectorated the causative agent. 
  • 1850:  Henry Hyde Salter believed asthma was a condition of airway spasms or convulsions caused by a nervous disorder.  He strongly inculcated the idea that asthma was nervous.  He was the first to state that asthma was not a humoral disease, but an actual disease of the lungs and mind.  
  • 1859: American physician J.A. Swett acknowledged that bronchospasm was important, but regarded 'bronchial inflammation' as the 'principal exciting cause of the paraxysm'. (1, page 109, 110)
  • 1859: Berkart rejected the idea that 'mysterious derangements of the nervous system' caused asthma, yet he saw little evidence that anti-spasmotics of that time benefited the disease. Based on this wisdom he believed asthma was a product of transient obstruction of the bronchi. (1, pp. 110)
  • 1873: Charles Harrison Blackley argued that symptoms of hay asthma (hay fever) were due to inflammation of the 'submucous cellular tissue' of the bronchi rather than 'spasm of the circular muscles of the bronchial tubes'. (1, pp. 110)
  • 1870s: Mucus plugs were discovered in the lungs of asthmatics(1, pp. 110)
  • 1890s: Eosinophils in both the sputum and the blood of asthmatics were found, which confirmed that inflammatory exudates layed a pivotal role in bronchial asthma (1, pp. 110).
  • 1892: In The Principles and Practice of Medicine, William Osler believed the theory of bronchospasm was not proven, and he suggested attacks of asthma were due to 'swelling of the bronchial mucus membrane' (later referred to as inflammation), otherwise referred to as inflammation of the smaller bronchi. He also believed asthma was caused by a reflex spasm of the diaphragm and other respiratory muscles. He acknowledged asthma as neurotic. He believed the relationship between hay fever and asthma deserved attention, because he believed if the changes in the mucosal membranes that occured with hay fever were to occur in the lungs, this would further explain a paroxysm of asthma (1, pp. 111, 112).
  • 1894?: Edouard Brissaud condisered the symptoms of asthma to be the product of both bronchospasm and hypersecretion, which constituted a form of 'bronchial urticaria' (1, 111).
  • 1895: Arthur Foxwell suggested attacks of asthma were characterized by a combination of bronchial oedema, bronchial constriction, and contraction of blood vessels in teh lungs (1, pp. 111).
  • 1959: The Condition of subjects with widespread narrowing of the bronchial airways changes its severity over short periods of time either spontaneously or under treatment. (American Thoracic Society: Am Rev Respir Dis 85: 762-785, 1962)
  • -- Asthma experts at this time were working hard to differentiate asthma from COPD. Although it was basically defined, in 1959, as a form of intermittent airway obstruction that could be reversed with bronchodilators. Chronic bronchitis was defined as productive cough, and emphysema was defined as dilation of the air-spaces distal to the terminal bronchi.**
  • 1962: Asthma is a disease characterized by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of the airways that changes in severity either spontaneously or as a result of therapy (Ciba Foundation Guest Symposium: Thorax 14: 286-299, 1959)
  • 1975: A chronic condition is characterized by recurrent bronchospasm resulting from a tendency to develop reversible narrowing of the airway lumens in response to stimuli of a level or intensity not inducing such narrowing in most individuals (World Health Organization: Bull World Health Organ 52; 251-260, 1975)
  • 1985: Reversible Obstructive Airway Disease: The acronym R-O-A-D was what I was taught in 1984 during my time at National Jewish Hospital/ National Asthma Center.
  • 1987: A clinical syndrome is characterized by increased responsiveness of the tracheobronchial tree to a variety of stimuli. Major symptoms are paroxysms of dyspnea, wheezing, and cough, which may vary from mild and almost undetectable to severe and unremitting (status asthmaticus). The primary physiological manifestation of this hyperesponsiveness is variable airways obstruction. This can take the form of fluctuations in the severity of obstruction, after the use of bronchodilators or corticosteroids, or increased obstruction caused by drugs or other stimuli. There is evidence of mucosal edema of the bronchi, infiltration of the bronchial mucosa or submucosa with inflammatory cells, especially eosinophils; shedding of epithelium; obstruction of peripheral airways with mucus. (American Thoracic Society: Am Rev Respir Dis 136: 1285-1298, 1987)
  • 1991: A lung disease has the following characteristics (1) airway obstruction that is reversible (but not completely so in some patients) either spontaneously or with treatment; (2) airway inflammation; and (3) increased airway responsiveness to a variety of stimuli. (National Heart Lung and Blood Institute, National Institutes of Health: Guidelines for the diagnosis and management of asthma, NIH pub no 91-3642, Bethesda, MD, 1991.)
  • 1992-1997: A chronic inflammatory disorder of the airways in which many cells play a role, particular mast cells, eosinophils, and T lymphocytes. In susceptible individuals this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough in early morning. These symptoms are usually associated with widespread but variable airflow limitation that is at least partly reversible either spontaneously or with treatment. The inflammation also causes an associated increase in airway responsiveness to a variety of stimuli. (National Heart Lung and Blood Institute, National Institutes of Health: International Consensus report on diagnosis and management of asthma, NIH pub no 92-3091, Bethesda, MD, 1992
  • 2010: A lung disease that is associated with chronic inflammation of the air passages (bronchioles) of the lungs. The bronchioles are therefore sensitive to various stimuli (asthma triggers) that should be harmless. The degree of inflammation determines severity. When exposed to asthma triggers the inflammation worsens, thus causing acute spasming of the muscles of the air bronchioles (bronchospasm) which causes the bronchioles to become narrow, thus trapping air inside the lungs. This is called an asthma flare, and results in coughing, wheezing, chest tightness and shortness of breath. The episode is reversible sometimes on its own, and sometimes with therapy. Between episodes breathing is normal for most patients.

1 comment:

  1. Every year there is an increase in the list that means there are more to come on the list.