Asthma Basics

Asthma has been recorded in medical history for thousands of years.   Chinese medical literature dating back 5, 000 years mentions asthmatic conditions, as do the greek physicians.  Since the 1950s and 60s asthma rates seem to be on the rise.  This illness now affects close to 10% of the population of many countries.  The World Health Organization (WHO) estimates that 235 million people are annually affected by asthma and approximately 250,000 people die of asthma per year worldwide.

Asthma, in western medicine, is considered an incurable disorder that requires long term management with medication.  Children may grow out of their asthma around puberty, but are at risk for developing asthma again later on in life.

Asthma is a respiratory condition which is defined by reversible hyper-reactivity of the airways.  What this means is that your lungs are more "twitchy" than those of a normal person, and they react to certain stimuli, known as triggers.  A trigger can be an allergen (inhaled ones such as pollen or dust mites, and some that are ingested orally like aspirin), pollution (dust, smoke, air contamination), stress, cold, or exercise.  Things like laughing, catching a cold or excessive talking may also result in asthma symptoms.

Symptoms of asthma include:  cough, wheezing, shortness of breath, chest pain, coughing up of phlegm and mucus plugs.  Accompanying symptoms may be allergic rhinitis (nasal congestion, runny nose, sneezing, itchy eyes and nose), sinusitis (blocked sinuses), hoarseness, fatigue, lack of concentration.  You can have one symptom alone or all of them together.  Often symptoms are worst in the early morning hours, or even at night.  If severe enough, asthma attacks may require hospitalisation.  Otherwise an attack is typically treated by opening the airways with a "rescue medication" (such as Ventolin - a short acting bronchial dilator).  

 

Uncontrolled asthma puts patients at risk for airway remodelling, which is hardening and scarring of the airway's smooth muscles  Over time this can make the lungs less efficient in their function of breathing and lead to chronic obstruction of the airways (COPD).  It is generally considered very important to attain good asthma control as poorly controlled asthma puts you at higher risk for complications, including fatal asthma attacks.  Poor asthma control also equals a miserable quality of life, severely restricting normal activities.  To this effect the advent of ICS (inhaled corticosteroids) in the 1980s has made a positive change to the management of asthma.  These medications are now made from yam derivatives instead of animal by-products, and have become widely available. 

 

Diagnosis:

 

Via spirometry- an improvement in lung function after use of bronchial dilators is a basis for diagnosing asthma.

 

Methacholine Challenge - if the diagnosis is unclear via spirometry, methacholine mist may be administered in increasing amounts (causing bronchial spasms).  If lung function declines by more than 20%, asthma is considered present.  This test is done only in adults.

 

Fractional Exhaled Nitric Oxide levels in the exhaled breath are measured in a machine called the NioxMino.  This level will be increased in asthmatics as a byproduct of the inflammation found in the lungs of asthmatics.

 

Blood tests - elevated IgE, eosinophils and or neutrophils all point to allergic disease

 

Blood or skin prick tests for allergens, both inhaled and ingested.

 

Induced sputum analysis - checking for eosinophil count in the sputum.  If present, allergic activity is diagnosed.  Eosinophilic asthma usually responds to steroid treatment.  Some people have neutrophil dominant asthma, and 80% or more of these do not respond to steroid treatment.

 

Chest and/ or sinus X-rays or CT scans to rule out other pathologies.  Chest X-rays are for simple asthma are usually normal, but sinus imaging may show polyps or congestion.

 

A general note on diagnosis:  millions of people are diagnosed or mis-diagnosed as asthmatics and treated as a “one size fits all”. 

 

Other Conditions that may mimic asthma symptoms:

 

Vocal Cord Dysfunction - more difficulty breathing in than out, symptoms don't respond to asthma meds, spirometry and lung function tests normal.  Caused by closing off of the vocal cords which can be triggered by inhaling irritants or from an upper respiratory infection, just as in asthma, causing SOB, wheezing, cough and hoarseness and tightness in the throat.  Wheezing sounds are auscultated upon inhalation and are higher pitched than normal asthmatic breathing (known as stridor). Asthmatic wheezing is usually more pronounced on exhalation.  Treated with special breathing exercises, speech therapy, counselling and avoidance of irritants.  Note that it is not uncommon for asthmatics to have VCD in addition to asthma.

 

COPD - usually the result of smoking or long term exposure to pollution, smoke or other irritants to the lungs (such as cooking over an open fire in unventilated rooms).  COPD results in chronically obstructed airways (as opposed to reversible obstruction seen in asthma).  The obstruction is caused by either:

Emphysema - destruction of the alveoli, which causes them to collapse upon exhalation.

Chronic bronchitis - chronic inflammation in the lungs due to chronic bronchitis can cause permanent obstruction in the bronchi. 

COPD symptoms usually include chronic coughing, clearing of the lungs in the mornings due to excessive mucus, smokers cough, wheezing, shortness of breath, fatigue, cyanosis (blue lips).  It is a progressive disease which is managed with similar medications as asthma (steroids and bronchial dilators).  Stopping smoking, exercise and healthy life style can all slow down the progression of COPD.  In late stages lung transplants are sometimes performed.

Alpha 1 Anti-trypsin deficiency - a genetic illness which affects the liver as well as the lungs.  Alpha 1 Anti-trypsin is a protein which is usually secreted by the liver and protects the lungs.  This is determined via blood analysis checking for the presence of the alpha 1 anti-trypsin protein.

 

Sarcoidosis: is an autoimmune disorder, that, when it affects the lungs, can mimic asthmatic symptoms.  It can present with wheezing, a persistent dry cough, shortness of breath and chest pain. Additional symptoms may include fatigue, fever, swollen lymph nodes and weight loss. It is an autoimmune disorder of uncertain ethology which causes granulomas to form in different organs, including the lungs, skin, eyes, heart.

 

GERD: acid reflux can cause marked bronchospasms, especially at night, while lying horizontally.  A chronic coughing or wheezing that is pronounced at night could be indicative.  It is thought that the cough is caused by an irritation of the vagus nerve.  This condition should improve with antacids or proton pump inhibitors (Omeprazol) before bed time (or changing diet and sleeping with at an angle).  Improvement with such measures is also diagnostic.

 

Congestive Heart Failure: or heart disease can cause back up of fluids into the lungs causing coughing, shortness of breath and wheezing.  Asthma meds will not help, but meds for cardiac issues should help in this case.  Diagnosis would be made by checking for accompanying symptoms for CHF and checking out the cardiovascular system.  This rarely occurs spontaneously, and is mostly seen in elderly patients or patients with a history of cardiovascular problems.

 

Asthma induced by medications:  some asthma can be caused by the use of NSAIDs like aspirin or beta-blockers.  Check medication intake and evaluate.  ACE inhibitors (Lisinopril, ramipril, capoten, lotensin) can cause a chronic dry cough in 10-30% of patients taking them, up to a year after beginning taking the medication, and exacerbate asthmatic symptoms.  Coming off the ACE inhibitors will eliminate these symptoms within some days.  

https://www.ncbi.nlm.nih.gov/pubmed/8862965

There is some evidence that taking iron supplements could counteract this effect.

http://www.webmd.com/heart-disease/news/20010816/on-ace-inhibitor-you-dont-have-to-cough-up-lung#1

 

Sensory Neuropathic Cough: (AKA Laryngeal Sensory Neuropathy) Similar to post-herpetic neuralgia or neuropathy, the vagus nerve remains irritated causing up to hundreds of bouts of severe coughing fits that are preceded by a sensation of irritation (tickle, dryness, scratch, mucus dripping) in the throat.  Coughing fits can be violent, lasting minutes at a time, and result in vomiting, gagging, tearing of eyes and nose, incontinence, broken ribs, sleep disturbance.  Treatment are neuralgia medications, like amitriptyline, desipramine, gabapentin, pregabalin or oxcarbazepine - need to be dosage adjusted depending on patient.  Another treatment may be capsacin. Consider this diagnosis in cases where asthma medications fail to work.  (www.laryngopedia.com)

Non-asthmatic eosinophilic bronchitis: Patients with a chronic, non-productive cough without apparent cause (infections, asthma) should be evaluated for eosinophils in their (induced) sputum.  A sputum eosinophil count >3% and unresponsiveness to asthma tests (methacoline challenge with spirometry) would be the diagnosis.  Treatment is with ICS, and if necessary, systemic coritcosteroids. 

 

Churg-Strauss Vasculitis (Eosinophilic granulomatosis with polyangiitis):  a rare auto-immune disorder affecting the vascular systems that has three stages that can occur in any order.  In the allergic stage patients experience asthma and sinusitis and allergic rhinitis symptoms.  In the Eosinophilic stage, high serum levels of eosinophils are present (>10%).  Depending on which body part is affected, this can cause fatigue, fever, loss of appetite and weight loss, joint pain, asthma, cough, abdominal pain and GI bleeding.  In the vasculitic stage the blood vessels become severely inflamed causing constriction and thus multi-system symptoms (cardiac digestive, bone, muscles, nervous system, skin, kidneys and bladder (symptoms can be weakness, fatigue, malaise, swollen lymph nodes, rash or skin sores, joint pain and swelling, severe neuropathy, severe abdominal pain, diarrhea, nausea, vomiting, SOB, cough, chest pain, arrythmias, hematuria).  This disease can be brought about in some asthmatics when coming off of Montelukast (Singulair) or corticosteroids.  Diagnosis is made by history (risk factors: asthma, eosinophilia, sinus problems, migratory lung infiltrates seen on lung imaging, polyneuropathy), auto-immune antibodies, tissue biopsy at affected sites, imaging (MRI) of lungs and sinuses. Treatment is with immune suppressants, initially steroids.  If that is not enough, other immune suppressants are used (cyclophosphamide, azathioprine (Azasan, Imuran) or methotrexate (Trexall).  Immune globulin infusions may help some patients.  Rituximab is a monoclonal antibody therapy that some respond to to lower eosinophil counts. 

 

CAUSES OF ASTHMA:

When it comes to finding root causes of asthma the literature is quite scant.  I often ask myself if we are barking up the wrong tree, spending millions in coming up with expensive pharamaceutical solutions rather than looking at the root cause of the problem and trying to address that.  There are some theories about why there has been such an increase over the last decades in asthma.  The one most often quoted being the hygiene hypothesis.  The idea is that we are not exposed to enough pathogens in our childhood, so our immune system is under challenged, with the result that non-pathogenic substances, such as pollen, suddenly become the targets of our immune cells.  This is thought to be the primary cause of most cases of asthma:  an allergic reaction which sends the twitchy lungs into hyperdrive when they are exposed to the allergen. However, the question, in my mind, is why do some people develop those "allergies" and others don't?  Why is it that one day you are perfectly healthy, and the next day you can become severely asthmatic?

Another thing you hear often by your doctors or when you read about asthma is that it is caused by inflammation in the airways.  While this certainly seems to be true, what causes the inflammation in the first place?  Inflammation is nothing other than the immune system trying to do it's job - for example if you cut yourself, the immune system is called into action to fight off any bacteria or debris at the site of the cut, and promote healing.  This causes some redness, heat and swelling until the job is done and the wound is healed up.  But what could cause your lung tissues to be chronically inflamed in the first place?  What event might trigger your immune system to become reactive to antigens (substances the immune system recognises) that in most people are totally benign?

The only thing that seems quite evident from epidemiological studies is the strong link between  viral respiratory infections and the onset/exacerbation of asthma.  Respiratory syncytial virus (RSV), metapneumovirus, coronavirus, parainfluenza and human rhinovirus are just some of the viruses which affect humans that are known to be connected with asthma.   It appears that they may be able to initiate asthma problems in the first place, and they certainly exacerbate asthmatic symptoms in the already asthmatic patient.

"Some emerging evidence has shown that individuals with asthma may have deficiencies in antiviral activity and a dysfunctional epithelial barrier, increasing susceptibity to severe viral respiratory infections with more potential for exacerbations." 

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674907/

https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-016-0479-4

Exposure to fungal spores may well be one of the triggers for initiation of asthma. This excerpt is from the European Respiratory Journal, (Denning DW, et al. The link between fungi and severe asthma: a summary of the evidence. Eur Respir J. 2006;27(3):615–26):

"Indeed fungal spores, which are potent allergens, are postulated to damage the epithelial barrier by inducing cell shrinkage and subsequent inflammation and barrier breakdown.

 

Exposure to fungal allergens can have a devastating impact on asthmatics. Fungi contain proteins which are detrimental to the airway epithelium, enhance additional reactions and also act as allergens. It is possible that the long term fungal colonisation of an atopic patient may provide a chronic source of allergen exposure, propagate airway inflammation and increase severity of asthma phenotype."

 

A basic blood test for mould exposure that overwhelms the immune system, called the C4a test, can get you started if you think you may fit into this category - for example if your asthma symptoms began after living in a damp house.

 

Unhealthy Intestinal & Respiratory Tract Flora - this is a hot topic of research which seems to indicate that having a balanced gut (and possibly lung) flora are essential to good health.  An unhealthy micro biome may cause inflammation of the intestines, leading to a "leaky gut", which means that substances that normally do not enter the blood stream now have free access to your innermost body parts, setting the immune system alight and causing auto-immune conditions and other illnesses.  Dr. Martin Blaser from NY University and author of the book "Missing Microbes" states: "Nearly every scientific study performed that has attempted to correlate the microbiome with specific traits or diseases has been successful.  In other words studies are finding that our bacteria (or lack thereof) can be linked to or associated with: obesity, malnutrition, heart disease, diabetes, celiac disease, eczema, asthma, multiple sclerosis, colitis, some cancers, and even autism."  One study showed that infants with low levels of Lachnospira, Veillonella, Faecalibacterium and Rothia  had a much higher chance of getting asthma during infancy.  Much energy is being put into understanding the implications of the differences in the micro biome found in asthmatics and COPD patients, both for etiological and therapeutic purposes.

 

The micro biome findings tie in to the hygiene hypothesis, as early use of antibiotics, C-section births, an unhealthy diet and lack of breast feeding are found to be associated with an increase risk of illness, including asthma.

Bacterial infections such as Chlamydiae Pneumonia and Mycoplasma Pneuomoniae have been found to contribute to cases of treatment resistant, adult onset asthma and have been successfully treated with long term use of macrolide antibiotics, for example Azythromycin. This has been extensively studied by Dr. David Hahn from the Univ. of Wisconsin.  See for example Hahn et. al, 

Azithromycin for Bronchial Asthma in Adults: An Effectiveness Trial (JABFM July–August 2012 Vol. 25 No. 4).

Parasitic Infections can also cause some asthmatic type syndromes, such as Ascariasis in Loefflers Syndrome and Strangyloides (see above).

Low cortisol levels have been found to be present in asthmatics.  It is interesting to note that asthma often improves or goes away completely when asthmatic children reach adolescence (a time in life marked by an increase in sex hormones), only to return at a later age when hormones decline again (as in menopause).  Also of note is that corticosteroids are the treatment of choice (and effective in most cases!) for asthma exacerbations.  The function of cortisol in our bodies is to keep the immune system in check.  This is why, for example, during periods of high stress you do not usually catch a cold (high cortisol in your system in response to the stress) - and the minute you relax, and your cortisol levels go down the cold takes a hold of you (just when you are going on vacation!).  Could it be then, that in people with asthma, the immune system is not kept in check as well, thus allowing it to run rampant?

Hormonal Fluctuations are tied in to the cortisol issue just mentioned.  It is interesting that there is a strong correlation in increased asthma symptoms during ovulatory and menstrual phases in women (see here).  

Pollution:  surprisingly one of the highest incidences of asthma is in New Zealand, which sort of throws the pollution theory of causing asthma out of the window.  The same is true for the old eastern block countries, which although had higher pollution levels, had lower levels of asthma than their Western European counterparts. Nevertheless there is also evidence that air pollution is associated with an increase in respiratory problems.

NON CONVENTIONAL VIEWS OF CAUSES OF ASTHMA:

Buteyko Theory states that asthma (and many other disorders) are a result of chronic hyperventilation which results in lower CO2 levels in the blood and in the alveoli.  Since CO2 is a bronchial dilator, the conclusion is drawn that chronically low CO2 levels (which the respiratory centre in the brain becomes accustomed to) results in bronchial constriction and even possibly inflammation (due to higher oxidative stress).  See Buteyko page.  Chronic hyperventilation results from a sedentary lifestyle, high stress, poor diet and overeating, overweight people, the belief in deep breathing being beneficial to health and improper breathing habits. 

Emotional blockages caused by childhood trauma may be one of the major culprits of asthma, as Dr. Peter Parkinson in his book "Smash Asthma" talks about.  He has seen many instances in which even very severe asthma will resolve almost instantaneously when the offending incidences are faced during "psychodrama sessions" (a form of therapy conducted in groups of supporting therapeutic "families").  His view is, interestingly, that the "adrenal-pituitary" axis is shut down during these traumas, leading to a lifetime of fear, and the resulting chronic asthma.

DIFFERENT TYPES OF ASTHMA:

Go to TYPES OF ASTHMA page

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