Before the world was ravaged by COVID-19, there was another highly infectious deadly disease — tuberculosis.
Tuberculosis is the second most deadly infectious disease in the world. It was only relinquished of its title of “most deadly infectious disease” when COVID-19 appeared. While COVID-19 is usually easy to treat, with most people not requiring any medication, tuberculosis can be fatal if not treated and treatment takes a minimum of 6 months.
According to the World Health Organization (WHO), approximately 10.6 million people fell ill with tuberculosis in 2021[1]. In Singapore alone, tuberculosis is endemic, with 1,306 new cases of active tuberculosis among Singapore residents [2].
To understand the gravity of being infected with tuberculosis, we must learn more about what it is and how it affects us.

What is tuberculosis?

Tuberculosis, commonly known as TB, is a highly infectious disease caused by a bacteria known as Mycobacterium tuberculosis. TB usually affects the lungs but can spread to other parts of the body such as the brain and spine. It is passed from person to person via respiratory droplets, but not everyone exposed to TB will develop symptoms.

There are two types of TB:

• Latent TB: you have been infected with the TB-causing bacteria but your immune system is keeping it at bay and preventing it from spreading and manifesting. You will not have any symptoms and you are not contagious. However, your infection may become active if your immune system weakens or you start consuming immune-compromising drugs.
• Active TB: you are showing symptoms of TB and are contagious, most active TB infections progress from latent TB.

What are the symptoms of active TB?

The symptoms of active TB are as follows:

• Persistent cough lasting longer than 3 weeks
• Low-grade fever
• Night chills
• Unintended weight loss
• Fatigue
• Chest pains
• Coughing up sputum (phlegm) or blood

How is TB diagnosed?

TB is diagnosed in the following ways:

• Skin test: also known as the Mantoux tuberculin skin test, a small amount of fluid is injected into your arm. If the spot swells after 2-3 days, you are considered positive for TB.
• Blood test: also known as interferon-gamma release assays (IGRA), TB proteins are mixed with a small amount of your blood to see the reaction.
• Sputum test: your sputum or phlegm is tested for the presence of TB bacteria.
• Chest x-ray or CT-scan: the appearance of your lungs can be studied for the presence of TB.

How is TB treated?

Both latent and active TB must be treated to prevent symptoms or the worsening of symptoms. Treatment usually involves a combination of antibiotics that must be taken over the course of 6 months to a year. After a few weeks of treatment, you will no longer be contagious — but you must continue with your treatment until the course of antibiotics is complete.
While most TB infections can be cured using antibiotics, there are some TB infections that are drug resistant. This means that the TB-causing bacteria have developed and is now resistant to certain medications. Hence a different group of medications will be used to treat it and must be taken for a much longer period of time, approximately 30 months or two and a half years.
Since TB is treated using antibiotics, the whole course of medication needs to be completed regardless of how you feel or if your symptoms are alleviated. If you do not complete the whole course of antibiotics, the TB-causing bacteria can multiply and grow back and may even become drug-resistant, making them even harder to eradicate.

What happens if TB is left untreated?

TB is not a disease that will go away on its own.
In fact, if TB is left untreated, 45% of HIV (human immunodeficiency virus) negative individuals will die, while nearly all HIV-positive individuals will die.
Furthermore, if you have untreated active TB, you can go on to infect 5-15 people at any one time as TB is easily spread when you speak, cough, sneeze, laugh, or spit, and it does not require a high concentration of bacteria to spread and infect others.

If active TB is left untreated, it could:

• Be fatal
• Spread
• Spread to other parts of your body such as your brain, spine, kidneys, etc.

Although individuals with latent TB do not have any symptoms and are not contagious, it is still important to treat them because their infection can progress to active TB if their immune system weakens or if they start taking immunosuppressive drugs.

What are the possible side effects/complications of TB medications?

Some individuals may experience the following side effects from TB medications:

• Jaundice, characterised by yellow skin or eyes
• Nausea or stomach discomfort
• Dark urine
• Rashes
• Itchy skin

What should I do if I have TB?

TB is curable if you adhere strictly to your treatment regime. If you have just been diagnosed with TB, you must observe the following to keep your loved ones safe:

• Wear a mask when in contact with them, especially during the first two weeks of treatment.
• Cover your mouth with a tissue when you sneeze or cough.
• Stay at home and isolated during the first two weeks of treatment.
• Complete your full course of TB medications.

What can I do to reduce my risk of an active TB infection?

There are various ways in which you can reduce your risk of an active TB infection, these are:

• Good hygiene habits such as washing your hands thoroughly and often
• Avoid close contact with others
• Getting vaccinated with the BCG vaccine
• Healthy lifestyle habits that help to boost your immune system

In conclusion, treatment for TB is absolutely necessary and should be started immediately once you have tested positive. Remember to complete all medications and isolate yourself for the first two weeks of treatment. TB is curable and is no longer the death sentence it once was. Get treated and get cured!

Any questions? Leave them for me here.

References

1. World Health Organization. (2022, October 27). Tuberculosis. Retrieved from World Health Organization: https://www.who.int/news-room/fact-sheets/detail/tuberculosis
2. Ministry of Health Singapore. (2022, March 24). Update on Tuberculosis Situation in Singapore. Retrieved from Ministry of Health Singapore: https://www.moh.gov.sg/news-highlights/details/update-on-tuberculosis-situation-in-singapore-2022

Asthma is a relatively common condition. According to a National Health Survey conducted from 2016-2018, approximately 11.9%[1] of Singaporeans aged between 18-60 were affected by asthma at some point of their lives.
To better understand what asthma is, let’s first understand how our lungs work, and then we can learn about allergic asthma.

How do our lungs work, and what is asthma?

Breathing is something we do without even thinking, but the whole breathing process is intricate and complicated. When you breathe, air travels down your throat and into your lungs. Within your lungs are tiny airways known as alveoli. Once air reaches the alveoli, it transfers to the surrounding blood vessels and is transported all over your body.

However, when someone has asthma, this process gets affected negatively, at times making breathing difficult.
Asthma is a chronic inflammatory disease of the airways in the lungs. It occurs when the airways and surrounding muscles swell and tighten. This causes a significant narrowing of the airways, leading to production of mucus which also contributes to the narrowed airways, making breathing difficult. The severity of asthma varies between individuals ranging from mild irritation to life-threatening.

Types of asthma

• Allergic asthma: asthma triggered by various allergens and can be linked to different seasons in seasonal countries.
• Non-allergic asthma: air irritants that are not linked to allergens and can trigger non-allergic asthma.
• Occupational asthma: asthma triggered by irritants found at some workplaces.
• Exercise-induced bronchoconstriction (EIB): asthma trigger by exercise within a few minutes of starting.
• Aspirin-induced asthma: severe asthma triggered by aspirin or other non-steroidal anti-inflammatory drugs (NSAIDS).
• Nocturnal asthma: symptoms of asthma that worsens at night.
• Cough-variant asthma (CVA): characterised by a dry, persistent cough and usually does not result in common asthma symptoms such as wheezing and breathlessness.

For the purposes of this article, we will be focusing on allergic asthma.

Can allergies cause asthma?

Yes, allergic asthma, or allergy-induced asthma, is asthma that is triggered by various allergens. These can range from pollen to even cockroaches; but often allergens that cause allergic rhinitis/hay fever have been known to trigger an allergic asthma attack.

An allergic reaction is caused by an over-reaction of our immune system. The main function of the immune system is to protect our body from dangerous or harmful substances that can make us sick.

However, sometimes the immune system mistakenly identifies harmless substances such as food, dust, pollen or other everyday items as harmful. When this happens, our body overproduces immunoglobulin E (IgE), an antibody when present in excess can cause your airways to:

• Become inflamed or irritated
• Produce large amounts of thick mucus
• Narrow due to tightened muscles that surround the airways

Worldwide, allergic asthma is responsible for 90%[1] and 50% of asthma cases in children and adults respectively.

What are the common causes of allergic asthma in Singapore?

According to Asthma Singapore [2], the common causes of allergic asthma in Singapore are:

• Cockroaches: dried droppings and dead cockroaches can trigger allergic asthma.
• Dust mites: dust mites and their droppings are common triggers of allergic asthma.
• Indoor mould: Singapore is a humid country and so indoor mould is fairly common especially in areas that are wet and humid. The spores produced by mould can trigger allergic asthma.
• Pet dander: proteins present in pet dander can trigger allergic asthma. Accumulation of pet fur can also result in other allergens appearing such as dust mites and cockroaches.
• Pollen: pollen produced by various types of trees such as the cotton tree can trigger allergic asthma.

How do I know if I have allergic asthma?

If you experience the following symptoms, you may have allergic asthma:

• Breathlessness
• Chronic coughing especially at night
• Wheezing
• Chest tightness

Symptoms that you might experience in conjunction with allergic asthma are:

• Hives or rashes
• Runny nose
• Watery eyes
• Sneezing
• Blocked or stuffy nose

Do I have asthma or just allergies?

One of the best ways to identify if you have asthma or allergies is to figure out where the reaction happens.

If you are experiencing symptoms in just your nose such as sneezing, congestion, watery nose, then chances are that you are having an allergic reaction. However, if you are experiencing symptoms in your lungs such as wheezing, chest tightness, breathlessness, then you are having an asthma attack.

Asthma attacks can vary in intensity and you must ensure that you have a treatment plan ready to help alleviate your symptoms and prevent them from escalating.
You are at a higher risk of developing allergic asthma if you:

• Have a family history of allergic reactions
• Have existing allergies to other substances

How is allergic asthma diagnosed?

Diagnosing allergic asthma is two-fold. First, an allergy test in conducted, then further tests will be conducted to diagnose for asthma.

Allergy test

• Skin prick/scratch test: thin needles with 10 to 50 allergens, are used to prick or scratch the skin on your back or forearm. Another way is to place droplets of allergens onto the pricked or scratched area. Checks for allergy to airborne allergens, food, and penicillin.
• Intradermal skin test: used if the skin prick test comes back negative or inconclusive. Small amounts of allergens are injected into the outer layer of your skin (the epidermis). Checks for allergy to airborne allergens, medications, and insect bites.
• Patch test: drops of the allergen are placed on your skin which is then covered with a bandage. After 48 to 96 hours, the bandage is removed to check for signs of an allergic reaction. Checks for the causes of contact dermatitis.
• Blood (IgE) test: a sample of your blood is taken and sent to the lab for analysis. Allergens are added to the sample of your blood and the levels of IgE (immunoglobulin E) are measured.
• Challenge tests: usually performed in a hospital setting. Individuals with a suspected food allergy must ingest small amounts of the food and an allergist will observe to see if any allergic reaction occurs.

Asthma testing

If your respiratory specialist (or pulmonologist) suspects that you have asthma based on your medical history and physical examination, the following diagnostic tests will be conducted for a more accurate diagnosis:

• Spirometry: checks how much air you can exhale and how fast you can exhale after a deep breath. This helps to identify if your airways are narrowed or restricted.
• Peak flow testing: measures how quickly you can exhale. Lower peak flow readings are signs that your lungs may not be working as well as it should.
• Bronchoprovocation testing: also known as the methacholine challenge, used to test how reactive your lungs are to certain triggers.
• X-rays: chest x-rays may be used to check if there are other issues causing your symptoms.
• Blood tests: may be used to check for possible infections.

Will allergic asthma go away?

Asthma is a chronic respiratory condition and there is no cure.
The main goal for asthma treatment is maintaining good control of your condition by reducing or minimising exposure to triggers. Continuous management and monitoring by your respiratory specialist are important.
In addition to reducing or minimising exposure to triggers, asthma can be treated with the following medications:

• Bronchodilators: help to relax the muscles around your airways, thereby preventing airway constriction.
• Anti-inflammatory medications: help to reduce inflammation, swelling, and mucus production.
• Anti-cholinergics: helps prevent your airway muscles from tightening
• Biologics: these target specific antibodies in your body to prevent asthma-causing inflammation.

Allergies can be treated in the following ways:

• Avoidance: limit or completely restrict exposure to the allergen.
• Medication: certain medications work to reduce the response of your immune system thus easing symptoms.
• Immunotherapy: also known as allergy shots, these are injections containing small doses of the allergens which are injected into your body, slowly training your immune system to recognise them as friend rather than foe.
• Anti-IgE therapy: medications that interfere with the production of IgE and hence prevents an allergic reaction.

Do you have any questions for me? Feel free to drop me a message.

References

1. Anitha Jeyagurunathan, E. A. (2021). Asthma Prevalence and its Risk Factors Among a Multi-Ethnic Adult Population. Yale Journal of Biology and Medicine, 417-427.
2. Asthma Singapore. (2016, April 26). Understand and manage asthma triggers. Retrieved from Asthma Singapore: https://www.asthmasingapore.com/asthma-singapore/managing-asthma/understanding-asthma-triggers.html

Smoking is a lifestyle habit that has been linked to multiple diseases such as heart disease, stroke, and multiple types of cancer. According to the Singapore Cancer Society1 and the World Health Organization (WHO)2, smoking is associated with at least 6 million deaths worldwide every year. If you are a smoker or know someone who smokes, read on to find out more about how smoking is associated with lung cancer.

What is lung cancer?

Our respiratory system is made up of organs and tissues that help us to breathe, with the lungs being the main organ involved. The lungs are two spongy organs made up of the right and left lung and are where the exchange of gases occurs.
When air is breathed in, it goes into the lungs which consist of the bronchi, bronchioles, and alveoli. The exchange of gases (oxygen and carbon dioxide) occurs here between the alveoli and the blood, for the removal of carbon dioxide and the supply of fresh oxygen.

Cancer occurs when cells in the body grow exponentially and out of control. When this originates in the lungs, it is known as lung cancer.
There are two main types of lung cancer:

• Non-small cell lung cancer (NSCLC): most common type of lung cancer and accounts for a large number of lung cancers. Develops from the epithelial cells (cells that line the organs) and includes adenosarcomas, large cell carcinoma, and squamous cell carcinoma.
• Small cell lung cancer (SCLC): associated with smoking and spreads quickly and easily to other parts of the body.

The most damaging characteristic of cancer is its ability to spread or metastasize to other parts of the body, which results in high mortality rates.
There are 5 stages of lung cancer – the higher the stage, the bigger the tumour and more severe the cancer. By stage 4, the cancer has already spread to neighbouring lymph nodes or other organs such as the brain or stomach.

What are the symptoms of lung cancer?

Lung cancer does not usually cause symptoms when it is still in the early stages. If symptoms are showing, it means that the lung cancer is already in the advanced stages.
Symptoms may include:

• Recurring and chronic cough
• Coughing up blood
• Chest pains
• Breathlessness
• Unintentional weight loss
• Hoarseness
• Headaches
• Bone pain
• Recurring lung infection
• Loss of appetite

How is smoking associated with lung cancer?

Smoking has long been associated with lung cancer and that is because cigarettes contain 7000 toxic chemicals with at least 70 known to be cancer causing. When smoke is inhaled, these chemicals enter your lungs and damage the DNA or deoxyribonucleic acids of your lung cells. Initially, your body responds by healing the damage; however, as time progresses and your smoking increases, your body will no longer be able to heal the damage, resulting in the formation of cancer cells.

These toxic chemicals also weaken your immune system making you more susceptible to infections and also reducing your body’s ability to identify, fight, and kill cancer cells. This coupled with the damaged DNA of lung cells, will result in the exponential and out of control growth and spread of cancer cells.
Smoking has also been associated with other types of cancers and diseases such as:

How common is lung cancer in smokers?

According to the Centres for Disease Control and Prevention (CDC), individuals who smoke are 15-30 times more likely to get or die from lung cancer than individuals who do not smoke3. Your risk of lung cancer increases with each day and cigarette you smoke. Studies have shown that even smoking just one cigarette a day puts you at an increased risk of lung cancer and other medical conditions.
People who quit smoking reduce their risk of lung cancer; this is also true for individuals exposed to secondhand smoke. Removing yourself from smokey situations can reduce your risk of developing lung cancer.
Although smoking is the main cause of lung cancer, there are also other causes such as:

• Secondhand smoke: living with a smoker or being in a long-term proximity of a smoker can increase your risk of lung cancer.
• Radon gas: radon gas is odourless, colourless, and tasteless. It is the second leading cause of lung cancer after smoking. It is a naturally occurring radioactive gas that can enter people’s homes through cracks or gaps in the ground.
• Asbestos and carcinogens: workplace exposure to these chemicals can increase your risk of lung cancer.
• Radiation therapy: previous radiation therapy on your chest or to treat another type of cancer can increase your risk of lung cancer.

What is the rate of lung cancer in Singapore?

The National Cancer Centre Singapore (NCCS) reported that lung cancer is the 3rd most common cancer diagnosed in both males and females in Singapore4. It has the highest rate of mortality (death) in Singapore because they are usually only discovered when symptoms start to show which is when the cancer is already in the advanced stages.

How can I reduce my risk of lung cancer?

• Quit smoking: the best and most effective way to reduce your risk of lung cancer, is to quit smoking or not start smoking in the first place.
• Avoid secondhand smoke: ensure that your home and car is smoke-free to reduce your risk of developing lung cancer.
• Screening: early detection can improve the curability of lung cancer, therefore if you are between the ages of 55 to 74 and have smoked 30 or more pack years, you are encouraged to go for a low dose computed tomography scan (CT-scan) used to screen for lung cancer.

In conclusion…

Smoking puts you at very high risk of lung cancer – not just yourself, but for your loved ones as well when they inhale your secondhand smoke.
If you are a smoker and want to screen or assess your risk for lung cancer, feel free to drop me a message and my friendly team will get in touch.

References

1. Singapore Cancer Society. (2022). Live a smoke-free life: What you should know about smoking. Retrieved from Singapore Cancer Society: https://www.singaporecancersociety.org.sg/learn-about-cancer/cancer-basics/what-you-should-know-about-smoking.html#about-smoking
2. World Health Organization. (2022, May 24). Tobacco. Retrieved from World Health Organization: https://www.who.int/news-room/fact-sheets/detail/tobacco
3. Centers for Disease Control and Prevention. (2022, October 25). Lung Cancer. Retrieved from Centers for Disease Control and Prevention: https://www.cdc.gov/cancer/lung/basic_info/risk_factors.htm
4. National Cancer Centre Singapore. (2022, March 8). Cancer Statistics. Retrieved from National Cancer Centre Singapore: https://www.nccs.com.sg/patient-care/cancer-types/cancer-statistics