“Chronic multisystem inflammatory disorder characterised by non-caseating granulomas (epithelioid cells and macrophages, surrounded by lymphocytes and fibroblasts)

Risk Factors
  • 20-60 Year Old
  • Female
  • African descent – African Americans much more likely to have lung involvement
  • Family History
Aetiology
  • The cause is unknown, likely be due to immune response to infection, chemicals, dust or self
  • Some people have a genetic predisposition
Pathophysiology
  1. T cell dysfunction and increased B cell activity result in local immune hyperactivity and inflammation.
  2. Formation of non-caseating granulomas within the lungs and lymphatic system- macrophages activate Th1 cells which in turn stimulate epithelioid cells and multinucleated giant cells via IFN-y.
  3. Epithelioid cells produce ACE and release cytokines to further activate the immune system.
  4. Fibrosis is due to cytokine release from epithelioid cells
  5. Calcium dysregulation and renal failure via 1-α hydroxylase production from activated macrophages (activates vitamin D pathway)
Clinical Presentation
  • Can be asymptomatic, found incidentally on imaging (especially CXR)
  • Typically begins with vague symptoms
    • Fatigue, weight loss, lymphadenopathy, joint pain and swelling
  • 1/3 are acute (remission within 2 years), 2/3 are chronic (may not be proceeded by acute sarcoidosis)
  • May occur with respiratory symptoms – Pulmonary Sarcoidosis
    • Persistent dry cough
    • SOB
    • Wheezing
    • Chest pain
  • May occur with skin symptoms
    • Red-purple rash on ankles
    • Lesions to nose/ cheeks/ ears,
    • Hyper or hypopigmentation
    • Nodules around scars/ tattoos
  • May occur with eye symptoms
    • Blurred vision
    • Eye pain
    • Burning/ itching
    • Redness
    • Photosensitivity
  • May occur with cardiac symptoms – Cardiac Sarcoidosis
    • Chest pain
    • Dyspnoea
    • Syncope
    • Fatigue
    • Arrhythmia
    • Palpitations,
    • Oedema
Investigations
  • Bloods:
    • Full Blood Count
    • Urea + Electrolytes
  • Imaging:
    • Chest X-Ray
    • PET or MRI if evidence of neuro/heart granulomas
  • Special:
    • Bronchoscopy – Gold standard – non-caseating granulomas with giant cells, increased CD4+ to CD8+ ratio
    • Urine Dip
    • Lung function tests
    • Biopsies of Skin Lesions
Management
  • There is no cure
  • Most patients manage without any treatment
  • Corticosteroids if disease progression or eye/ heart affected
Complications
  • Dependant on the affected area
    • Pulmonary fibrosis
    • Retinal damage
    • Cataracts
    • Glaucoma
    • Renal calculi
    • Reduced renal function
    • Arrhythmias
    • Inflammation of nerves (esp facial nerve, leading to facial paralysis)   

Leave a Reply

Search Our Notes

Get Updates

Get updates direct to your inbox as we post more notes!

Our Latest Notes