Overview

Almost everyone has heard of asthma and may even know someone who suffers from it. Asthma is a lung disorder characterised by the narrowing of the airways, which causes shortness of breath, wheezing, and a cough. In severe cases, urgent medical care is warranted; however, asthma can be managed by the patient using their inhaler as indicated. An asthma attack can be triggered by exercise, respiratory infections, air pollutants, and allergens. Below we will discuss the role of aspirin in asthma.

About Asthma

Asthma is a chronic condition affecting adults and children. In this particular lung disorder, the airways swell and become narrower, making it difficult to breathe and can make you cough. The lungs also produce extra mucus, which can cause wheezing. There is no permanent cure, but it is manageable. For some people, asthma is just a minor nuisance, but for others, it can be a major interference in their day-to-day life as it has the potential to lead to a life-threatening asthma attack.¹ Symptoms can change over time, so it is important to let your doctor know if you notice anything different so your treatment can be adjusted.

Symptoms

The symptoms of asthma vary from person to person. Some have sporadic events, while others have symptoms all the time. These include shortness of breath, chest tightness or pain, wheezing upon exhaling, and coughing or wheezing attacks that are worsened or exacerbated by a cold or flu.² 

Causes and Risk factors

It is not exactly known how people develop asthma; however, viral infections, a family history (especially asthma on the mother’s side), and the environment (for example, being around smoke) play a role for most people. These combined factors can affect lung development and your immune response. Other risk factors include; allergies, obesity, ethnicity, sex, and occupational hazards.³

Triggers

For people suffering from asthma, respiratory infections, allergens, chemicals, strong smells, exercise, seasonal changes (very cold or dry air), emotional stress, or cigarette smoke or other air pollutants can irritate the lungs, but also certain medicines, like aspirin, and cause serious breathing problems. These are all called triggers.³

What is aspirin-induced asthma?

Aspirin-induced asthma (AIA) is a type of asthma triggered by aspirin (acetylsalicylic acid). It is also triggered by other non-steroidal anti-inflammatory drugs (NSAIDs). It consists of a clinical trinity of asthma, chronic inflammation of the nasal mucosa, the paranasal sinuses with nasal polyps (chronic rhinosinusitis) and the onset of an asthma attack when using aspirin or other NSAIDs. This trinity is also known as Samter’s triad.^4,5  In the adult asthmatic population the prevalence is around 4-10%.⁴ 

Other names

Aspirin-induced asthma is now mostly known as aspirin-exacerbated respiratory disease (AERD).⁴

Causes of aspirin-induced asthma

The cause of aspirin-induced asthma is aspirin. Aspirin is a member of a group of medications called NSAIDs. They are used to treat fever, pain, and also inflammation. People can also take low doses of aspirin to protect themselves from heart disease. AIA is more common in people with severe asthma.^4,6

Signs and symptoms of aspirin-induced asthma

AIA usually starts up within two hours of ingestion but can present in as soon as minutes. Symptoms are a runny or blocked nose, itchy or swollen eyes, hives, redness in the face and neck, stomach pain, and breathing difficulties. About 6% of people will go into shock.^6,7

How does aspirin trigger asthma?

Dr A. Szczeklik was the first to put forward a hypothesis that bronchospasms, or an asthma attack, after taking aspirin were not an allergic response but rather a pharmacological one. His theory was that when asthmatics take drugs, like aspirin, it will inhibit the enzyme cyclooxygenase 1 (COX-1), making it stop accelerating its chemical reaction and trigger an asthma attack. The known COX-1 inhibitors are aspirin and other NSAIDs. There are also drugs available that inhibit COX-2 and do not cause these adverse reactions.⁸ 

The mechanisms are still being studied as the aetiology is quite complex. However, most evidence points toward an abnormality in the arachidonic acid mechanism where COX-1 is a regulator, and without it, the formation of protective prostanoids is hindered. Instead, cysteinyl leukotriene is synthesised, which has bronchoconstriction and mucus production effects, resulting in breathing difficulties.⁴ 

Other drugs that may trigger asthma

Medication-triggered asthma attacks may be rare, but the reactions can be fatal. Other non-steroidal anti-inflammatory drugs that may trigger asthma are naproxen and ibuprofen. Other medications that may trigger an asthma attack are beta-blockers and ACE inhibitors.⁶ It is entirely possible that other drugs can elicit an asthma attack, so please pay attention to any symptoms that occur when you start new medications.

Alternative drugs for people with aspirin-sensitive asthma

People with AIA need to avoid these medications.  As an alternative to treat pain, fever, and inflammation, asthmatic patients may take acetaminophen (paracetamol) in low or moderate doses. As mentioned previously, COX-2 inhibitors (nimesulide, meloxicam) are also better tolerated by the majority.^9,10

Diagnosis

A clinical diagnosis of AIA can be made if all three of the previously mentioned triad are present: asthma, nasal polyposis and respiratory reactions to aspirin and NSAIDs. If there remains any uncertainty, the patient will be given aspirin, in a clinical setting to confirm the diagnosis; this is called an aspirin challenge.^4,5,11

Treatment for aspirin-induced asthma

AIA can be treated with medication or with surgery, but the first course is avoidance. If everything else fails, the patients can undergo aspirin desensitisation which can induce a tolerance to aspirin. This usually leads to improvements in about 60% of the cases.¹¹

Medication

Patients with asthma are typically treated with steroids. In order to decrease the inflammation in the nose and shrink down the nasal polyps, steroids can be used in the form of a nasal spray. As with any patient with asthma, treatment with inhaled corticosteroids is the usual protocol, and unfortunately, a subset of patients will need continuous systemic corticosteroids on a daily basis.¹¹  Another type of medication is leukotriene receptor antagonists, like montelukast and zileuton. These are usually prescribed when the asthma is mild and can prevent it from getting worse. Additionally, there is a newer group called biologics or biologic medications, like dupilumab, mepolizumab and omalizumab, which may also be beneficial.¹²

Surgery 

To get rid of the nasal polyps, surgery is often required, although surgery may not permanently remove them. The recurrence rate is quite high, especially when aspirin desensitisation is not performed. A full-on endoscopic sinus surgery followed by aspirin desensitisation has been shown to mitigate the need for revision surgeries.^13,14

Home treatment

There are no known home remedies to treat AIA other than to avoid aspirin and NSAIDs and to follow the advised use of your prescribed medication.

Diet

People have reported relief of symptoms when following a low-salicylate diet, like the Feingold diet, which makes sense as the body converts aspirin into salicylic acid. However, this diet also eliminates the intake of beer and wine, and as patients with AIA tend to have respiratory reactions when consuming alcohol, this could potentially be the reason for the reported improvements. A diet low in omega-6 oils, precursors of arachidonic acid, and high in omega-3 oils can also be beneficial.^15,16  

Complications

Asthma is a chronic disease. It can affect their quality of life significantly as asthmatic attacks can interfere with a person's daily routine such as exercise, and missing out on school or work. Severe asthma attacks can be life-threatening and require medical care. The majority of people with asthma suffer from night-time asthma symptoms which impairs their sleep cycles. Frequent asthma attacks and uninterrupted inflammation of the airways can lead to structural changes. This is called airway remodelling; the layers of cells in the lining of the airways become overgrown and the muscles surrounding the airways become thicker. When this occurs, medication might not be fully effective in opening the airways. It is currently unknown if these changes are permanent.

In addition, long-term use of steroids has its own side effects, like high blood pressure, osteoporosis, cataracts, and Cushing's disease.¹⁷  

When to seek medical care

When you are starting a new medication, it is important to look out for symptoms like shortness of breath, chest tightness or pain, wheezing upon exhaling, and coughing or wheezing attacks.² If you are experiencing these symptoms, you need to let your doctor know as your asthma attack might require urgent medical care quickly after the onset of these symptoms. 

Summary

An asthma attack has several triggers, including aspirin. When you suffer from aspirin-exacerbated respiratory disease (AERD) or endure an aspirin-induced asthma (AIA) attack, please be aware that it is possible that other factors are at play. Avoid aspirin, NSAIDs, omega-6 oils and alcohol if possible and increase your omega-3 oils as this can be beneficial and potentially have a hand in increasing your quality of life. When AERD is confirmed by a doctor, it is best to start aspirin desensitisation.