Sarcoidosis

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Example Management | References

Definition

Sarcoidosis is a multisystem inflammatory disease characterised by the formation of non-caseating granulomas in various organs, most commonly the lungs and lymphatic system. The cause of sarcoidosis is unknown, and it can affect individuals of any age, but it typically presents in adults under the age of 50.

Aetiology

The exact cause of sarcoidosis is unknown, but it is believed to involve a combination of genetic, environmental, and immunological factors:

• Genetic predisposition: Certain genetic factors may increase susceptibility.
• Environmental triggers: Possible associations with infections, allergens, and occupational exposures.
• Immune system dysfunction: Abnormal immune response leading to granuloma formation.

Pathophysiology

Sarcoidosis is characterised by the formation of non-caseating granulomas, which are clusters of immune cells that form in response to chronic inflammation. These granulomas can disrupt the normal structure and function of affected organs. The lungs and lymphatic system are most commonly involved, but other organs such as the skin, eyes, liver, and heart can also be affected.

Risk Factors

• Age: Most commonly diagnosed between ages 20 and 50.
• Sex: Slightly more common in women.
• Ethnicity: Higher prevalence in African Americans and Northern Europeans.
• Family history: Increased risk if a close relative has sarcoidosis.
• Occupational and environmental exposures: Certain exposures may trigger the disease.

Signs and Symptoms

• Respiratory symptoms: Persistent dry cough, shortness of breath, and chest pain.
• Fatigue and general malaise.
• Skin lesions: Erythema nodosum, lupus pernio.
• Eye involvement: Uveitis, conjunctivitis.
• Lymphadenopathy: Swollen lymph nodes, particularly in the chest.
• Joint pain and arthritis.
• Hepatosplenomegaly: Enlarged liver and spleen.

Investigations

• Clinical history and physical examination, focusing on multisystem assessment.
• Chest X-ray: To identify hilar lymphadenopathy and lung infiltrates.
• High-resolution CT scan of the chest for detailed lung assessment.
• Pulmonary function tests: To assess lung function.
• Blood tests: Riased ESR, elevated serum angiotensin-converting enzyme (ACE) levels, hypercalcaemia.
• Biopsy: To confirm the presence of non-caseating granulomas in affected tissues.
• ECG and echocardiogram: If cardiac involvement is suspected.
• Ophthalmologic examination: To assess for eye involvement.

Management

Primary Care Management

• Initial assessment and referral to a specialist (e.g., pulmonologist, rheumatologist) for further evaluation and diagnosis.
• Supportive care, including managing symptoms and providing information and support to patients and families.
• Monitoring for complications, such as pulmonary fibrosis or cardiac involvement.

Specialist Management

• Corticosteroids (e.g., prednisolone) as the mainstay of treatment to reduce inflammation and granuloma formation.
• Immunosuppressive therapies (e.g., methotrexate, azathioprine) for patients with severe or refractory disease.
• Hydroxychloroquine for skin and joint involvement.
• Organ-specific treatments: Depending on the organs affected (e.g., inhalers for lung involvement, eye drops for uveitis).
• Regular follow-up and monitoring of disease progression and treatment side effects.

Example Management for Sarcoidosis

A patient presenting with symptoms of sarcoidosis, such as persistent cough and skin lesions, should be referred to a specialist for a comprehensive evaluation, including chest X-ray and biopsy. If diagnosed, the patient may be started on corticosteroids to reduce inflammation and granuloma formation. Immunosuppressive therapies may be considered for severe cases. The patient should receive multidisciplinary care, including monitoring for complications and regular follow-up to assess treatment response and adjust the care plan as needed.

References

1. NICE. (2024). Sarcoidosis: Diagnosis and Management. Retrieved from NICE
2. NHS. (2023). Sarcoidosis. Retrieved from NHS
3. Iannuzzi, M. C., et al. (2007). Sarcoidosis. New England Journal of Medicine.
4. Judson, M. A. (2015). Sarcoidosis: Clinical Presentation, Diagnosis, and Approach to Treatment. American Journal of Respiratory and Critical Care Medicine.
5. Statement on Sarcoidosis. (1999). American Thoracic Society. American Journal of Respiratory and Critical Care Medicine.

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