Fungal lung diseases

What is a fungal disease?

There are lots of different types of fungus (plural fungi) ranging from ones you can eat (e.g. baker’s yeast and edible mushrooms) to ones that can cause infections and other health problems.

Some fungal infections you may have heard of include thrush, fungal nail infections and athlete’s foot. These are all mild skin and nail infections that are readily treatable with over-the-counter treatments from your local pharmacist.

However, health problems caused by fungi can sometimes become more serious, particularly if they affect the lungs.

Types of fungal lung disease

Fungal spores – microscopic particles that enable fungi to multiply and spread – are always in the air around us and we are continuously breathing them in.

Thankfully, this rarely causes problems for healthy people as our immune systems normally get rid of the spores.

If fungi cause lung disease, they do so in two ways:

1. The fungal spores can cause irritation and inflammation of your airways, usually in those with asthma.
2. The fungal spores can infect the tissues of your lungs, usually if you have a weakened immune system.

See below for more information about both types of fungal lung disease.

Fungal disease symptoms

Asthma and fungal sensitivity

If you have asthma, it can be made worse if your lungs are sensitive to fungi.

It is estimated that of adults with asthma severe enough to be referred to a specialist, 50% have sensitivity to one or more types of fungi that cause disease.

Severe asthma with fungal sensitisation

If you have severe asthma (asthma that cannot be controlled with conventional treatments), you may have severe asthma with fungal sensitisation (SAFS).

A blood test can help your doctor understand whether you have a sensitivity to fungi, and this is making the symptoms of your asthma worse – in this case, you may have SAFS. Your doctor may also conduct a skin prick allergy test if they feel it is needed to determine sensitivity to fungi.

Allergic bronchopulmonary aspergillosis

‘Allergic bronchopulmonary aspergillosis (ABPA) affects 1% of patients with asthma and like SAFS, can make asthma more severe. However, your lungs will be sensitive to a specific type of fungus called Aspergillus. ABPA can result in dilatation of your airways, recurrent infection and flares of your asthma.

What causes fungal disease?

Aspergillosis: A common fungal lung infection

The main type of fungal lung infection in the UK is called aspergillosis and like ABPA is caused by the Aspergillus fungus.

Healthy people rarely get this fungal lung infection, but it can cause severe disease if you have a weakened immune system caused by another health condition (such as cystic fibrosis) or you are taking medication that suppresses your immune system (such as treatments for cancer or rheumatoid arthritis).

Aspergillosis

Your health can be affected by aspergillosis in different ways depending on how the infection spreads or other health problems you may have.

Aspergilloma

If you have another health condition that causes a cavity (a large abnormal air-filled space) to form in your lungs, this can lead to the development of an ‘aspergilloma’.

An aspergilloma is a large ball of fungus and this can lead to complications such as coughing up blood, which can be life-threatening. Health conditions that cause cavities to form in your lungs include COPD, tuberculosis infection and sarcoidosis.

Invasive aspergillosis

If your immune system is severely weakened, such as if you are receiving chemotherapy for cancer or are having a bone marrow transplant, you could be at risk of invasive aspergillosis.

This is a serious form of the fungal infection as it can spread from your lungs to other parts of the body, including the brain.

Diagnosing fungal disease

An allergy test can help your doctor understand whether your asthma symptoms are made worse by sensitivity to fungi. Most commonly we can detect allergy to fungi using a blood test, but we may occasionally recommend a skin prick allergy test if we feel it is needed.

An allergy test will help your doctor understand if you have severe asthma with fungal sensitisation (SAFS) or allergic bronchopulmonary aspergillosis (ABPA).

Diagnosing fungal lung infections

Diagnosing an aspergilloma or invasive aspergillosis can be difficult for your doctor.

Symptoms such as fever, cough and shortness of breath are not specific to these lung conditions and they can be confused with others. These fungal lung infections also don’t always cause symptoms.

If your doctor suspects you might have any of these fungal lung infections, they may need to refer you to a centre specialising in their diagnosis such as Royal Brompton and Harefield hospitals.

We may need to conduct a lung scan (such as a CT scan) or consider using a bronchoscopy (telescope examination of your lungs) to enable direct  sampling using fluid from your lungs to understand the presence of fungal infections. Special blood tests can also help determine whether you have an infection.

Our interventional radiologists, histopathologists, medical mycologists (fungal diagnostic pathologists) and respiratory and infectious disease consultants are experts in the diagnosis of fungal lung diseases. They can help with a quick and accurate diagnosis.

Fungal disease treatment

Studies have shown promising results in treating both severe asthma with fungal sensitisation (SAFS) and allergic bronchopulmonary aspergillosis (ABPA) with antifungal medications. They work to ease your symptoms and help you breathe better.

Our respiratory consultants are experts in asthma care and can recommend the best treatment plan to control your asthma symptoms, whether they be due to fungal sensitivity or another cause such as allergy to plant pollen or animal dander (e.g. cat hair).

Treating fungal lung infections

Treatment for fungal lung infections is specific to the type of infection.

For an aspergilloma, long term antifungal therapy has been shown to be successful in up to 60% of patients. However, surgery may be needed to remove the section of the lung affected, if this is a suitable option for you.

We will explore a range of options to prevent life-threatening bleeding in the lungs from an aspergilloma and our cardiothoracic surgeons are world leaders in minimally invasive surgical procedures.

For invasive aspergillosis, treatment will depend on how the infection has spread in the body. Antifungal treatments are provided, but more targeted and supportive therapies may be needed depending on which organ or tissue is affected by the infection.

Occasionally, patients can experience an aspergillosis infection that is resistant to antifungal treatments. Our specialists can conduct tests to determine whether this is the case and change the antifungal treatment given to ensure the best outcomes. For this reason, continuous antifungal drug monitoring by a specialist is recommended.

Our respiratory and infectious disease experts, Dr Anand Shah and Professor Darius Armstrong-James, are both key academic researchers in fungal lung disease, with a broad portfolio of basic and clinical research through both Imperial College London and King’s College London.

They can treat all types of fungal lung disease, from the common types listed to rarer fungal lung diseases that may be picked up while travelling or while working in environments that increase the risk of exposure.