What is eosinophilic asthma and what makes it different?

Asthma is a common condition which affects the airways. Many of us can identify the hallmark signs of asthma: wheezing, breathlessness, coughing and chest tightness, to name a few. These symptoms may be triggered by any number of factors including exercise, allergy and air quality.

Getting to know triggers, if any, is essential to prevent symptoms from happening in the first place and to get on the right treatment regime.

Types of asthma

Asthma can have different symptoms ranging from mild to severe. Someone with mild, intermittent asthma symptoms may find that their asthma doesn't cause too much disruption to their everyday activities and that it can be managed by using an inhaler when needed.

Someone on the other end of that spectrum with severe, persistent symptoms may find themselves struggling with breathlessness, wheezing or coughing throughout the day and might need different types of treatment to control their condition.

Eosinophilic asthma is a rarer, more severe form of asthma. Studies suggest fewer than 1 in 100 people with asthma have the severe eosinophilic type with symptoms that aren't controlled with standard treatment. It's unusual in that it tends to have its onset in adulthood rather than in childhood and is often resistant to many of the usual treatment options. This can make recognising and managing symptoms more challenging.

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What is eosinophilic asthma?

Eosinophils are a type of white blood cell which increase inflammation and swelling to assist healing. These cells are an important part of the body's immune response when recovering from injury or illness. But too much inflammation and swelling can cause problems, including eosinophilic asthma.

The most common types of asthma tend to begin in childhood, with many people experiencing symptoms before they are 5 years old. Although eosinophilic asthma can develop at any age, it most commonly starts when people are aged between 35 and 50.

"Though many common types of asthma are closely linked to a family or personal history of allergic conditions such as eczema and hay fever, people with eosinophilic asthma usually have no history of allergy," explains Dr Sarah Jarvis, GP and Clinical Director at Patient.info.

What are the symptoms of eosinophilic asthma?

Wheezing is often one of the early signs of asthma. But if you have eosinophilic asthma, you're more likely to experience shortness of breath as asthma symptoms develop rather than the classic whistling sound which comes with wheezy breathing.

Some of the common symptoms of eosinophilic asthma include:

• Breathlessness.

• Wheezing.

• Coughing.

• Tightness in the chest.

• Eczema.

• Nasal polyps.

• Chronic sinusitis.

If you experience ongoing breathlessness, wheezing or coughing fits, whether at rest, exercising or just going about your daily activities, it's important to speak to your doctor as soon as possible. In an emergency if you or someone else is struggling to breathe, call 999.

What is the treatment for eosinophilic asthma?

There's no cure for eosinophilic asthma but many people can manage symptoms using inhalers. Other people may respond better to a combination of inhalers and other asthma treatments like tablets, injections, surgery or complementary therapies.

As with any other form of asthma, avoiding smoking can help improve symptoms. If you're sensitive to common triggers, such as fumes, chemicals, passive smoke or exposure to animals you're allergic to, you should do your very best to avoid these too.

"The combination of shortness of breath and severe symptoms that don't respond to standard 'preventer' inhaler treatment always prompts me first to check inhaler technique. Not using your inhaler regularly is likely to mean it won't work as well as it should. Next, I ask about whether my patient is taking their medicine really regularly. Many patients don't recognise the importance of taking preventive inhalers really regularly because most versions don't provide immediate relief.

Still getting symptoms despite taking their inhaler regularly, at the right dose and with the right technique, would always be a flag to me that eosinophilic asthma could be at the root of a patient's problems," says Dr Jarvis. "Nasal polyps and/or sinusitis can also help to differentiate eosinophilic asthma from other types of asthma - this increase in eosinophils can lead to inflammation in other parts of your body outside your lungs.

"Eosinophilic asthma often doesn't respond to standard treatment, particularly inhaled steroids which are the mainstay of treatment for standard asthma. That means it is often harder to control using conventional treatments, and symptoms can be severe.

"However, there are several 'biologic' medicines which have been proven to improve severe symptoms in eosinophilic asthma. These have to be started by a hospital chest specialist."

Biologic therapies help stop the body's processes that lead to lung inflammation, which in turn causes asthma symptoms. Your GP or a specialist may be able to talk you through the treatment options available. Finding the right treatment may be a case of trying a few options to find the best one for you. But the first step to getting eosinophilic asthma under control is to identify it and start working with your medical team to manage your symptoms.

What should I do if my asthma is uncontrolled?

When asthma is left uncontrolled, symptoms may continue to get worse and affect your daily activities. You may also be at risk of asthma attacks which can be life-threatening.

Questions to consider

When you speak to your GP, they will ask you a number of questions about your symptoms. It is worth making notes beforehand so you don't forget anything during your appointment. Questions are likely to include:

• What are your symptoms?

• When did your symptoms begin?

• Are there any triggers for your symptoms?

• Have you experienced anything like this before?

• Does anything relieve your symptoms? Have any previous treatments helped?

• Does anyone in your family have a history of asthma or allergy?

Next steps

Sometimes getting a diagnosis for severe asthma can take some time because symptoms may be slightly different to the usual presentations of asthma or not respond to regular treatment options.

"Doctors and nurses in primary care need to consider the possibility of eosinophilic asthma in patients whose symptoms aren't controlled, particularly if they have atypical features such as those above," explains Dr Jarvis. "If they consider this as a possibility, patients are more likely to be referred for the appropriate treatment if their symptoms are hard to control."

Your GP may carry out blood tests to check eosinophil levels in your blood or refer you to a specialist asthma service for investigations and treatment.