Tuesday, April 22, 2014

1768: Asthma classified as a disease

Prior to the 19th century the symptom was the disease, and the treatment was some form of supernatural remedy. And even when an herb was the remedy, the reason it worked was rationalized by superstition. Of course the other common remedy was a simple prayer, which worked through efforts of the gods or God worshipped.

For the most part, prior to the transition from superstition to science, diseases were merely symptoms. For example, if you were short of breath you had asthma unless there was some other rationalization for your dyspnea, such as tuberculosis or influenza or pneumonia. Asthma, in a sense, was a symptom more so so than a disease.

T.E. Weckowicz and H. Liebel-Weckowicz, in their book "History of Great Ideas in Abnormal Psychology," explain that prior to 18th century (and even during the 18th century for the most part) illness was categorized by the Constitutional models that were devised by Hippocrates and Galen, which emphasized symptoms. (1, page 168)

During the 18th century a shift was made away from the Constitutional model and toward the disease model of disease.  Weckowicz and Weckowicz propose three theories as to why this may have occurred.  (1, page 68)

1.  They suggest that various epidemics of diseases "suggested the possibility of contageon."  They mention Girolamo Fracastoro of Verona (1484-1553) who "wrote a famous poem about syphilis.  He postulated that diseases were caused by minute germs which passed from one person to another. He recognized that smallpox, measles, bubonic plague, phtisis (tuberculosis) were contagious diseases." (1, page 68)

They also mention Fracastro, the Jesuit Father, Athanasius Kirchner (1602-1680) who "claimed to have found microscopic worms in the blood of patients suffering from infectious diseases."  While the "link between bacteria and infectious disease was not definitely established until the middle of the nineteenth century," the idea was beginning to grow in the minds of the medical profession, or at least the scientific community. (1, page 68)

2.  They suggest that "clinitians tended to isolate the symptoms of disease from the total patient and to treat them as entities in themselves." (1, page 68)

3.  "There was a growing interest in morbid anatomy. The bodies of dead people were dissected, the diseased organs were examined, and the pathology of the organs was linked with the symptoms of the patients." An example here may be the diagnosis of the disease pneumonia by the observation of fluid or puss in the parts of the lungs that they ultimately attributed to the symptoms the person had prior to death, such as dyspnea and coughing up colored secretions. (1, page 68)

Weckowicz and Weckowicz list the significant figures in the birth of nosology, or the classification of diseases, and I will list some of the ones most significant to our asthma and allergy history here.  (1, page 68-9)

1.   Felix Plater:  (1536-1614)  (He considered asthma as a mental disorder.  He observed the asthma attack when nothing else seemed to be wrong)  He classified nervous disorders, dividing them into "idiots, morons, cretons, mutes, and melancholics." (1, page 69)

2.  Thomas Willis:  (1621-1675) (He was the person often given credit as the first to classify asthma as a nervous disorder).  He's also known as among the first two men to classify psychological diseases.  He classified mental patients as "melancholics, maniacs, idiots, and Apoplectics." (1, page 69)

3.  Dr. Thomas Syndenham (1624-1689):  He was among the first to favor the disease model as opposed to the constitutional model of Hippocrates and Galen.  He stressed, in his book Medical observations Concerning History and Cure of Acute Diseases (Sydenham, 1848), that "each disease should be treated by the specific remedy for it." (1, page 68)

He also stressed the importance of nosology (classification of disease), and he suggested such classification should be made similar to the methods used to classify plants and animals. He also classified diseases according to their symptoms. (1, page 68-9)

4.  Theophile Bonet of Geneva:  (1620-1689) "He compiled all the existing knowledge of pathological anatomy in his work Sepulchretum." (1, page 68)

5.  Dr. Carl von Linne (Linneaus):  (1707-1778) He continued work on the classification system started by Sydenham, and he classified plants according to genera, families, and orders.  He also "treated diseases as plant species." (1, page 71)   He published his works on nosology in his 1763 book "Genera Morborum."  
6. Francois Boissier de Sauvages de Lacroix: (1706-1767) He classified disease in his book Nosologie Methodique (Systematic Nosology). In this book "he distinguished twenty-four hundred diseases which he divided into ten classes, each further divided into several orders and genera. (1, page 71)

Lineaus was a medical student when Sauvages first book was published in 1731, and the two met and started corresponding.  This led to a lifelong friendship whereby the two "influenced one another" in forming classification systems.  In 1763 they both published their own treaties on nosology, Linnaeus published Genera Morborum and Sauvages published Methodical Nosology. (3, page 98)

Sauvages also was mentioned by Dr. John Charles Thorowgood in his 1878 book "Asthma and Chronic Bronchitis." Thorowgood notes the following:  (2, page 10)
As knowledge and observation progressed, the intermittent character of the breath difficulty of asthma was duly observed and insisted on; and we find Boissier de Sauvages, in his 'Genera Morborum' (1768), defining asthma as 'difficultas spirandi periodice recurrens, chronica.'(2, page 10)
In this way, Boissier de Sauvages may have actually been the first person to classify asthma as a disease as opposed to just a symptom. 

7.  William Cullen:  (1710-1790)  I'm actually adding him to this list on my own because he was also among the first nosologists.  He was a physician from Edinburgh, and he was among the first to base his theories of asthma on studies he performed.

He believed most diseases, asthma included, were caused by some disorder of the nervous system.  He found it difficult to classify asthma as a disease mainly because most other physicians of his day believed all or most cases of dyspnea were asthma.

He was among the first physicians to study signs and symptoms of diseases while a person was awake, and compare this with findings on autopsy.

According to Thorowgood, Culen defined asthma in his 1772 book "Synopsis Nosologiae Methodicae" as follows: (2, page 13)
 'spirandi difficultas, cum angustise in pectore sensu, per intervalla subiens.' (2, page 13)
He believed spasmotic asthma was caused by constriction of the muscles that wrap around the smaller bronchiole tubes.  This theory, which was also supported by John Floyer, received a lot of attention among the medical community through the 19th century, said Thorowgood.  (2, page 13)

There were many ardent supporters of this theory during the course of the 19th century, and I will list them and discuss their contributions to asthma in a later post.

Thorowgood also said that Cullen further classified asthma into the following three groups: (2, page 13)
  1. Idiopathic Asthma:  There are 8 varieties of this
  2. Symptomatic Asthma: There are 2 varieties of this
    1. Gouty Asthma (asthma arthriticum)
    2. Syphilitic Asthma (Asthma Venereum)
  3. Other:  This "consists of a long list of asthmas, dyspnoeas, and orthopnoeas symptomatic of cardiac and pulmonary difficulties and obstructions  (2, page 13)
Conclusion:  So these are some of the earliest nosologists responsible for the early categorization. The systems created by Sydenham, Linneaus and Sauvages made nosology popular, and during the 1760s through the 1780s there were an abundance of treaties dedicated to nosology, with Cullins work being among them.  (3, page 98)

So, throughout the 18th century physicians were on a quest to match the symptoms that occured in life with what they saw on autopsy.  The more they did this the more diseases they discovered, and this resulted in an effort to classify these diseases in order to organize them.

The next rush among the medical community would be to further understand the various diseases.  Yet they would soon find out that asthma left no scars, and therefore was not so easy to define.  The debate as to what causes asthma would be fought long and hard by many physicians during the 19th century.

References:
  1. Weckowicz, T.E. and H. Liebel-Weckowicz, "History of Great Ideas in Abnormal Psychology,"1990, New York, Elsevier Science Publishing Company, Inc. 
  2. Thorowgood, John C., "Asthma and Chronic Bronchitis: A New Edition of Notes on Asthma and Bronchial Asthma," 1894, London, Bailliere, Tyndall, & Cox
  3. Flangsmyr, Tore, J.L. Heilbron, Tobin E. Rider, editors, "The Quantifying Spirit in the Eighteenth Century," Berkley, Los Angeles, Oxford, University of California Press
  4. Butlin, H. Trentham, President of the Laryngological Society of London, "Proceedings of the Laryngological Society of London elected at the annual meeting January 13th, 1897," 1897, London, Printed by Adlard and Son

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