Interstitial Lung Disease

Information

Interstitial lung disease (ILD) refers to a group of conditions that cause inflammation and scarring of the lung interstitium. This leads to breathlessness, cough, reduced lung function and impaired oxygen exchange.

Diagnostic terminology includes:

idiopathic pulmonary fibrosis (IPF)
hypersensitivity pneumonitis (e.g. bird fanciers lung)
connective tissue disease associated ILD (CTD-ILD) and rheumatoid arthritis associated ILD (RA-ILD)
idiopathic interstitial pneumonia (IIP)
sarcoidosis
rare diseases such as pulmonary vasculitis, cystic lung disease and suspected occupational diseases, namely asbestosis and pneumoconiosis

The causes of ILD can vary widely and may include:

Environmental factors: Long-term exposure to harmful substances such as asbestos, silica dust, or other pollutants
Autoimmune diseases: Conditions like rheumatoid arthritis or systemic lupus erythematosus can lead to ILD.
Medications: Certain drugs, including chemotherapy agents and some antibiotics, can cause lung damage
Idiopathic: In many cases, the exact cause of ILD remains unknown.

Symptoms

Common symptoms of ILD include:
- Shortness of Breath: Especially on exertion, which may worsen over time.
- Dry Cough: A persistent cough that does not produce mucus.
- Fatigue: General tiredness and decreased exercise tolerance.

Clinical signs include finger clubbing and velcro-like inspiratory crackles on chest auscultation.

Diagnosis of ILD typically involves:

Medical History and Physical Examination: Assessing symptoms, exposure history, and family history.
Imaging Tests: Chest X-rays and HRCT scans to visualise lung changes.
Pulmonary Function Tests: To measure lung capacity and function.
Lung Biopsy: In some cases, a biopsy may be necessary to determine the specific type of ILD.

Treatment

There is no cure for most forms of ILD, treatment focuses on managing symptoms and slowing disease progression. Options may include:
Medications: Corticosteroids and other immunosuppressive drugs to reduce inflammation, anti-fibrotics to target lung scarring and slow disease progression.
Oxygen Therapy: To help maintain adequate oxygen levels in the blood.
Pulmonary Rehabilitation: A program that includes exercise training and education to improve lung function and quality of life.
Lung Transplant: In severe cases, a lung transplant may be considered.

Prognosis

The prognosis for individuals with ILD varies widely depending on the specific type of disease, its cause, and how early it is diagnosed.
These conditions tend to be complex and can be difficult to diagnose.
Idiopathic pulmonary fibrosis (IPF) is the commonest ILD and has an average survival from first symptoms of only 3-5yrs. However the disease can run an unpredictable course and most patients with suspected IPF will be followed up indefinitely in the ILD clinic.
The ILD clinic is the only local access to a specialist ILD nurse, newly licensed speciality anti-fibrotic drugs and relevant clinical trials, therefore early referral to the ILD service is essential.

L.N & D.M – 6-8-26

Who can refer

Any primary or secondary care clinician can refer.

Who to refer:

Refer via sci-gateway
- Patients of any age with suspected ILD including sarcoidosis
  - IPF typically presents in those >50 yrs with breathlessness, finger clubbing (sometimes), cough, fine bibasal velcro chest crackles and a diffusely abnormal CXR
  - Sarcoidosis typically presents in young patients (20-50yrs) with erythema nodosum, fatigue, lymphadenopathy and abnormal CXR

Who not to refer:

Patients who have a clear-cut cause for breathlessness eg COPD or heart failure
Patients with asymptomatic asbestos-related pleural plaques and otherwise normal CXR. See Asbestos Related Diseases – RefHelp

How to refer:

All referrals for suspected ILD should be made using Sci-Gateway – RIE or WGH or SJH > Respiratory medicine > LI Basic Sign Referral and freetext reason for referral in presenting complaint.
A CXR should always be performed prior to referral. A normal CXR virtually excludes ILD.
Spirometry is not useful without gas transfer for ILD so please don’t book spirometry in suspected ILD. The ILD clinic will book full PFT when triaging the referral.
The vast majority of ILD is not urgent. The only exceptions are of rapidly progressing ILD (worsening symptoms within a few months) or suspected pulmonary vasculitis.
All ILD referrals are triaged by a consultant or specialist ILD nurse.

After referral:

Most suspected ILD patients will be sent a health questionnaire specific to ILD prior to clinic appointment, please let patients know to expect this.
The triaging Respiratory clinician will often organise a high resolution CT scan and detailed lung function tests prior to clinic review, so patients can be informed they may receive letters for these appointments prior to clinic.

Early diagnosis is paramount in the management of ILD. Please have a low threshold for requesting a CXR in patients with SOBOE and a persistent dry cough.
Please consider referring ILD patients with SOBOE to pulmonary rehabilitation.
Please consider referring patients with advanced ILD to community palliative care for symptom control.
Please signpostpatients to the Action for Pulmonary Fibrosis website for further information, https://actionpf.org