According to the British Lung Foundation, over 12% of the UK population have received an asthma diagnosis [1]. The common condition, typically characterised by symptoms such as wheezing, shortness of breath and coughing, does not always manifest itself in the same way. In this article, we break down the seven different ways asthma may appear, and identify the triggers that tend to cause these variants. Whilst these seven types of asthma are not exclusive of each other, they each have distinctive characteristics relating to their triggers or symptoms.
1. Allergic asthma (extrinsic/atopic asthma)
Allergy-induced asthma is a common asthma type that usually begins in childhood. It occurs when the immune system misidentifies allergens as threats to the body. When these allergens are inhaled, swallowed or touched, the body releases antibodies that result in the lungs becoming inflamed. Allergens that commonly cause this reaction includes:
- Pollen
- Fungi
- Pet dander
- Mould
- Dust mites
Approximately 4 out of 5 allergic asthma sufferers have an associated condition such as hay fever, eczema or food allergies [2].
2. Nonallergic asthma (intrinsic/nonatopic asthma)
If you experience any asthma symptoms that are not triggered by allergens, this is known as nonallergic, intrinsic or nonatopic asthma. Whilst the symptoms themselves are often identical to allergic asthma symptoms, the triggers are different and can sometimes be harder to pinpoint. The condition typically occurs later in life than allergic asthma, and the symptoms can be more severe. Common nonallergic asthma triggers include the following:
- Stress
- Changes in the weather
- Exercise (see point 4)
- Infections
3. Occupational asthma
This type of asthma, due to triggers in the workplace, accounts for approximately 15% of disabling asthma cases. Methods of identifying occupational asthma include if your asthma improves when you’re away from your workplace, if your symptoms started when you changed jobs, or if certain chemicals make breathing difficult. Over 250 manufacturing substances have been associated with aggravating asthma symptoms, including the following: [3]
- Paints, varnishes and adhesives
- Dust particles of wood, such as from sanding
- Metals like platinum, chromium or nickel sulphate
- Plant substances, such as natural rubber latex, cotton or wheat
- Gas or fumes, such as chlorine gas, sulfur dioxide, smoke, or from cleaning products
Depending on the concentration of the irritants you’re exposed to, asthma can develop anywhere from a few days to a few months later [4]. Workers who may be at the most risk or developing workplace asthma include:
- Detergent / drug manufacturers and laboratory workers
- Bakers, millers and farmers
- Metal, plastic or wood workers
- Textile workers and carpet makers
- Hairdressers
- Health care workers
4. Exercise-induced bronchoconstriction (EIB)
9 in 10 asthma sufferers experience some breathing difficulty while exercising [5]. Whilst exercise is not the cause of asthma, it can often be a trigger. Air conditions have a lot to do with the severity of EIB, with cold, dry air triggering symptoms more than warm, humid air. Allergic asthma triggers such as pollen, alongside other airborne irritants like pollution, may exacerbate asthma symptoms further when exercising outside, and combine with EIB to cause an asthma attack. Symptoms of EIB, such as wheezing and difficulty breathing, may occur a few minutes into exercise and can last up to 24 hours, or may reappear as a second wave 4 to 12 hours after exercise. Although exercise can trigger your asthma, this is not a reason to avoid doing exercise, as this may in fact worsen your asthma symptoms; it’s vital to build lung resilience by exercising regularly, just make sure you have a reliever inhaler on hand for when needed.
5. Aspirin-induced asthma
Up to 1 in 5 adults with asthma have a sensitivity to aspirin or other NSAIDs such as ibuprofen or naproxen. You may get a severe asthma attack upon taking one of these medications, so if you do have aspirin sensitive asthma, they should be completely avoided. For over-the-counter pain relief, alternatives such as paracetamol might be a safer option. It’s vital to read the labels on all pain, cold and flu medication to check if they’re suitable for people with aspirin-induced asthma.
If you have nasal polyps as well as asthma, your chances of having aspirin sensitivity is between 30% and 40% - the combination of these three conditions is known as Samter’s triad [6].
6. Nocturnal asthma
Nocturnal, or nighttime, asthma is when you have particularly bad symptoms during the evening and nighttime hours. This involves the usual asthma symptoms, such as coughing, wheezing, and inflammation of the airways. Just under half of asthma sufferers will experience nocturnal asthma, and whilst health professionals debate the exact reasoning symptoms are worse at night, factors that commonly trigger include the following:
- Having a cold or flu
- Dust, pet dander and other allergens
- Acid reflux
- Mucus build-up and sinusitis
- Being reclined as you sleep (as secretions in the airways can build up)
- Hormones (levels of epinephrine - that relaxes the bronchial tubes - are lowest at night)
The ramifications of nocturnal asthma can be severe, with disrupted sleep causing fatigue and lack of concentration in the day. For instance, nighttime asthma has been found to negatively affect children’s mental performance and functioning at school [7].
You can learn how to prevent and control the condition is our dedicated nocturnal asthma guide.
7. Cough-variant asthma (CVA)
Cough-variant asthma is when asthma presents solely as a chronic cough, as the body attempts to rid itself of the particles causing irritation. The cough is typically dry, and is not accompanied by the other usual symptoms. However, 2 in 5 people with CVA will progress to classic asthma if left untreated. Those with CVA are also at increased risk of permanent narrowing of the bronchial tubes, lung failure, pneumonia, fractured rib, and asthma attacks that do not respond to treatment. CVA tends to be treated with inhaled corticosteroids.
To learn more about asthma symptoms and how to treat them, check out our ultimate guide to asthma.