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Sarcoidosis

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Overview

Sarcoidosis is a multisystem condition of unknown aetiology characterised by non-caseating (without a necrotic centre) granulomas (abnormal collections of inflammatory cells). It most often affects the lungs but can manifest at various sites in the body, making its diagnosis difficult.

Epidemiology

  • More commonly seen in African-American people
  • Usually seen in adults <50 years

Risk Factors

  • Age 20-40 years
  • Family history
  • Female sex
  • African-American ethnicity

Presentation

The presentation can vary widely depending on what sites are affected. Classical presentations in exams are:

Some features seen may be:

  • Cough – usually dry
  • Dyspnoea – gradual in onset
  • Wheeze on auscultation
  • Lymphadenopathy – usually axillary, cervical, inguinal, and submandibular
  • Symptoms of uveitis:
    • Red, painful eye
    • Blurred vision
    • Photophobia
  • Erythema nodosum
  • Lupus pernio – hardened, raised, purple lesions on the nose, cheeks, lips, and ears

Other possible features can be:

Differential Diagnoses

Lymphoma

  • Cervical and supraclavicular lymphadenopathy are more common
  • Lymph node biopsy would be needed to differentiate the two

Tuberculosis (TB)

  • Fever may be present
  • Chest X-rays may show upper zone lesions
  • Smear or cultures are positive for TB

Investigations

All patients

  • Chest x-ray:
    • Can be normal
    • May show bilateral hilar lymphadenopathy
  • Serum calcium:
    • Hypercalcaemia is often present due to the cells in the granulomas producing calcitriol
  • Serum ACE:
    • Usually elevated
  • Urea and electrolytes (U&Es):
    • May be deranged
  • Tuberculin skin test (Mantoux):
    • Usually negative
  • Erythrocyte sedimentation rate (ESR):
    • Usually raised
  • Tissue biopsy:
    • Shows non-caseating granulomas

Diagnosis

Pulmonary sarcoidosis radiographic staging

  • Stage 0: normal chest x-ray
  • Stage I: bilateral hilar lymphadenopathy
  • Stage 2: bilateral hilar lymphadenopathy + pulmonary infiltrates
  • Stage 3: pulmonary infiltrates only
  • Stage 4: pulmonary fibrosis

Management

Overview

Patients with mildly abnormal lung function do not need treatment and can be managed conservatively. The mnemonic ‘PUNCH’ can be used to remember when oral steroids are indicated:

  • Parenchymal lung disease (stage 2 or 3 + symptomatic)
  • Uveitis (eye involvement)
  • Neurological involvement
  • Cardiac involvement
  • Hypercalcaemia

Complications

Complications occur depending on what organs are affected:

  • Respiratory:
  • Cardiac:
    • Arrhythmia
    • Cardiac failure
  • Ophthalmological:
    • Uveitis
  • Dermatological:
    • Chronic refractory skin disease
  • Neurological:
    • Neuropsychiatric problems
    • Cranial and peripheral nerve damage
    • Strokes and transient ischaemic attacks
  • Other:

Prognosis

  • Around 1-5% with sarcoidosis die due to complications
  • Around 20% of patients have permanent symptoms due to irreversible lung fibrosis

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