Sarcoidosis is a systemic inflammatory condition characterised by the formation of granulomas, which are tight clusters of immune cells. These can develop in almost any organ in the body, most commonly the lungs, lymph nodes, skin and eyes. In many people the condition resolves on its own, but in others it can persist and cause lasting organ damage. Without appropriate management, progressive granuloma formation can impair organ function and significantly affect quality of life. Early assessment is important because untreated sarcoidosis can cause irreversible organ damage, particularly to the lungs, eyes and heart. Prompt evaluation supports better long-term outcomes.
What is sarcoidosis?
Sarcoidosis is an inflammatory condition defined by the formation of tiny inflammatory cell clusters called granulomas. The areas most commonly involved include:
- Lungs and lymph nodes, which are the most frequent sites affected by these granulomas.
- Other organs, such as the skin, eyes, liver, heart, kidneys and nervous system, where clusters can also develop.
The condition can affect people of any age but most often develops between the ages of 20 and 60. It is more common in women than men and occurs more frequently in people of African-Caribbean descent. In some people, sarcoidosis follows a mild and self-limiting course, but in others it becomes chronic and can cause progressive damage to affected organs if left untreated.
What are the causes of sarcoidosis?
The exact cause of sarcoidosis is not fully known, but it is thought to develop when the immune system overreacts to an unidentified external trigger. Key elements of this response include:
- An abnormal immune reaction to an external substance
- Overreaction of the immune system leading to granuloma formation
- Development of the condition primarily in genetically susceptible individuals
- Potential triggers initiating an inflammatory cycle in the body
Demographic and genetic risk factors:
While the exact trigger is not fully understood, certain individuals are more predisposed to developing sarcoidosis. Key risk factors include:
- A family history of sarcoidosis
- African-Caribbean or Scandinavian ancestry
- Age between 20 and 60
- Female sex
Environmental and exposure risk factors:
External substances and occupational settings can also play a major role in triggering the condition in susceptible individuals. Key risk factors include:
- Occupational exposure to organic dusts
- Occupational exposure to mould
- Occupational exposure to chemicals
- Previous infections, which may act as a trigger
What are the symptoms of sarcoidosis?
Symptoms vary depending on which organs are involved and the extent of inflammation. Common features include:
- Persistent dry cough, shortness of breath, or chest pain or tightness
- Fatigue, low energy, fever, night sweats, or unintentional weight loss
- Swollen lymph nodes or joint pain and swelling
- Skin changes or eye redness, pain, or blurred vision
Some people have no symptoms at all and are diagnosed incidentally during investigations for another condition. Because symptoms can overlap with many other conditions, obtaining an accurate diagnosis is important.
Respiratory Symptoms
Sarcoidosis frequently affects the respiratory system, presenting as a persistent dry cough, shortness of breath, or chest pain and chest tightness.
Systemic and Organ-Specific Symptoms
It can also cause fatigue, fever and night sweats, weight loss, swollen lymph nodes, skin changes like raised red patches or lumps, eye redness, pain or blurred vision, joint pain and swelling, and facial weakness or drooping if the nervous system is affected.
When to Seek Medical Advice?
You should seek specialist assessment if you have:
- Persistent respiratory symptoms such as cough or breathlessness that do not resolve
- Unexplained fatigue
- Skin changes
- Eye symptoms
- Swollen lymph nodes
- Symptoms that put you at risk of irreversible organ damage, particularly to the lungs, eyes and heart
How is sarcoidosis diagnosed?
Dr Nuttall will begin with a detailed review of your symptoms, medical history, occupational history and family history, alongside a physical examination, as there is no single test that confirms sarcoidosis. Investigations for sarcoidosis may include:
- Physical examination and detailed symptom review
- Blood tests, including serum calcium, angiotensin-converting enzyme (ACE) level, liver function and inflammatory markers
- Advanced imaging:
- Chest X-ray
- CT scan of the chest
- Pulmonary function tests, urine tests, eye examinations, ECG or cardiac imaging, and a tissue biopsy to confirm non-caseating granulomas
Diagnosis involves a combination of clinical assessment, imaging, and tissue sampling to identify granulomas and to exclude other conditions that can cause similar findings. Different patients require different investigations, and your diagnostic pathway will be tailored to your symptoms and clinical findings to evaluate organ involvement.
How to treat sarcoidosis?
Not everyone with sarcoidosis requires treatment. In mild cases where symptoms are manageable and organ function is preserved, watchful waiting with regular monitoring may be appropriate, while more progressive cases require targeted interventions to suppress inflammation.
Medical management and treatments
When treatment is needed, the aim is to suppress inflammation, protect organ function and improve symptoms. Treatment options may include:
- Corticosteroids, such as prednisolone, which are the main treatment for moderate to severe sarcoidosis and help reduce granuloma activity
- Steroid-sparing immunosuppressant medications if long-term treatment is required or corticosteroids are not tolerated (eg. Methotrexate, Azathioprine, Mycophenolate)
- Hydroxychloroquine, which is particularly useful for skin and joint involvement
- Biologic agents, such as infliximab, for refractory disease that has not responded to standard treatment
Monitoring and specialist care
Long-term health preservation relies heavily on routine monitoring and interdisciplinary referrals:
- Regular monitoring of lung function, eye health, calcium levels and organ function to detect progression or complications
- Specialist referral to respiratory medicine, ophthalmology, cardiology or neurology depending on the organs involved
Dr Nuttall will tailor treatment to reduce inflammation, preserve organ function, and support your long-term health and quality of life.
