Response to the “What is Asthma 2” presentation.
The presentation is quite insightful and at the same time thought provoking, and I noted a two things. First, it is indeed true that neurogenic theory does not comprehensively explain asthma pathogenesis, and immunological theory does not explain all asthma features such as airway hyperreactivity. Second, you have mentioned that asthmatic patients have been reported to have higher parasympathetic tone, yet it has never been suggested as an underlying causal factor for the disease. This raised several questions, but the one that stood out most is, “what role does the parasympathetic system play in airway hyper-responsiveness?” According to Hamid, Shannon and Martin (2005), asthmatic patients have increased airway resistance even during remission periods, and there is evidence suggesting that their increased basal tone is partially mediated by increased parasympathetic tone since anticholinergic drugs are known to inhibit the latter. These drugs decrease airway hyper-reactivity when exposed to irritants such as distilled water, histamine, bradykinin and capsaicin, and this only indicates that the parasympathetic system is involved in airway reactivity. Consequently, your assertion that high parasympathetic firing leading to increased production of NO (Nitrogen oxide) would explain immunologic and neurogenic events that occur during asthma pathogenesis is well founded. In this case, I do agree that a higher parasympathetic tone in combination with inflammation or certain genetic backgrounds can modify the effects of NO on human lung homeostasis leading to hyper-reactivity and other asthma features.
References:
Hamid, Q., Shannon, J., & Martin, J. (2005). Physiologic basis of respiratory disease (pp. 367-368). Hamilton: BC Decker, Inc.
Response to the “Extrinsic Asthma” presentation.
First, environmental exposure and allergens play a significant role in the exacerbation of symptoms and thus in vitro testing, and skin testing should be done to assess the patients’ sensitivity to various indoor and outdoor allergens. Once the allergens are identified, patients should be counselled on how to avoid them as much as possible with a major emphasis on home, school, and workplaces since this is where most triggers are found. There is also need to provide complaint corticosteroid inhaler treatments especially during seasons where viral infections such as influenza and rhinovirus are prevalent (Morris & Pearson, 2016).
References:
Johnston, N. & Sears, M. (2006). Asthma exacerbations {middle dot} 1: Epidemiology. Thorax, 61(8), 722-728. http://dx.doi.org/10.1136/thx.2005.045161
Morris, M. & Pearson, D. (2016). Asthma: Practice Essentials, Background, Anatomy. Emedicine.medscape.com. Retrieved 10 May 2016, from http://emedicine.medscape.com/article/296301-overview
