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Dr Tatenda Simango

I trust you are keeping well and are in good spirit. Winter is coming and with it some medical conditions become more common. We shall discuss asthma this week.

Asthma is characterised by recurrent episodes of reversible airway obstruction. Cases are recorded as far back as ancient Egypt. The word takes its origins from the Greek word meaning “panting”. Its rate increased significantly in the 1960s. It is thought to be caused by a combination of genetic and environmental factors. It usually has its first attacks in early childhood; from as young as one year. However, it can also have its onset in late adulthood.

It is characterised by recurrent episodes of wheezing, chest tightness, shortness of breath, and coughing, which may produce sputum or phlegm. If severe one may be unable to complete a sentence. It may be triggered by cold weather, exercise, infection, air pollution, allergens, drugs (aspirin/betablockers) and smoking — active or passive. Certain jobs put one at risk, such as painting, food processing, welding, mining and animal handling. Some people only experience asthma in response to triggers, whereas others may have frequent and/or experience persistent symptoms.

Onset below 12 years of age may be attributed to genetic factors and onset after 12 years is generally attributed to environmental factors. Smoking during pregnancy and exposing a baby to cigarette smoke is associated with an increased risk of asthma. Countries with high levels of air pollution have increased cases of the condition. Asthma is associated with exposure to indoor allergens. Common indoor allergens include dust mites, cockroaches, animal dander (fragments of fur especially dog and cat or feathers), and mould. Efforts to decrease dust mites have been found to be effective on symptoms in sensitised subjects.

Both viral and bacterial infections of the upper respiratory tract can worsen the disease. There is a correlation between obesity and the risk of asthma. Perfumes are a common cause of acute attacks in women and children. Psychological stress may worsen symptoms — it is thought that stress alters the immune system.

Certain viral respiratory infections, such as respiratory syncytial virus and rhinovirus, may increase the risk of developing asthma. Initially it was thought people with asthma were at increased risk for severe Covid-19 outcomes, although evidence is emerging contrary to this. Under normal circumstances, viral infections are a big driver of flares in asthma patients, but research indicates asthma patients with Covid-19 do not appear to have a higher rate of hospitalisation or mortality compared with other Covid-19 patients (Linda Rogers, MD, of Icahn School of Medicine at Mount Sinai in New York City).

The hygiene hypothesis attempts to explain the increased rates of asthma worldwide as a direct and unintended result of reduced exposure, during childhood, to non-pathogenic bacteria and viruses. It has been proposed that the reduced exposure to bacteria and viruses is due, in part, to increased cleanliness and decreased family size in modern societies. Exposure to bacterial endotoxin in early childhood may prevent the development of asthma, but exposure at an older age may provoke bronchoconstriction. Evidence supporting the hygiene hypothesis includes lower rates of asthma on farms and in households with pets.

In simple terms, when one is experiencing an asthmatic attack from the possible allergens discussed above, it causes the airways to be affected at its terminal section called bronchioles. Smooth muscles in this section contract causing the classic wheeze. In addition to the contraction of airways there is increased mucus production and there is also marked swelling of the of the lining of the airways. Narrowing is typically reversible with or without treatment.

Diagnosis of asthma is made from clinical history and examination. Tests maybe be done for the diagnosis. The best is spirometry, it measures how much and how fast you can move air into and out of your lungs.

Treatment includes medications called quick-relief, or “rescue,” medicines that only need to be taken during an asthma attack. Controller medicines help reduce inflammation in the airway to keep an asthma attack from happening in the first place, these work best when taken daily. Medication includes inhalers, pills and syrups.

There are myths arising from misconceptions on the condition. Asthma drugs do not stop working overtime, they remain effective if regularly used as directed. An asthmatic should engage in physical activity as this keeps the lungs resilient. It is important that your doctor helps stabilise your condition to prevent one from getting attacks whilst exercising. This is not a contagious condition.

Asthma is a lifelong condition that may improve with age. The current treatment guidelines are moving away from the use of salbutamol pills to the metered salbutamol inhaler as this has been seen have less side-effects (body shakes and fast heart rate). One does not die if their inhaler runs out as per common belief.

There are no proven foods or nutrients that prevent or treat asthma. We do encourage a well- balanced diet low in fat and red meat and high in whole grains, fruits and vegetables.

The condition is not a psychological condition. Asthma is a chronic long-term condition, so patients with asthma may always need to take medication, but it is not because they are addicted to the medication.

Management tips to prevent recurrent attacks include good inhaler technique, quitting smoking, avoid precipitants, once a year spirometer tests to assess control of disease.

Let us maintain Covid-19 prevention practises. Let’s minimise unnecessary travel and keep our families safe, till next week, happy Africa Day.

Dr Tatenda Simango can be contacted on [email protected] or follow him on Facebook@ 9th Avenue Surgery.