Sarcoidosis

Question 1

Define

Answer 1

Multisystem granulomatous inflammation disorder of unknown cause

Question 2

Cause

Answer 2

aetiology unknown
? Potentially due to transmissible agents (e.g. viruses, atypical mycobacterium, Propionibacterium acnes), environmental triggers or genetic factors

Question 3

Risk factors

Answer 3

associated with HLA-DRB1 and DQB1 alleles

Question 4

Epidemiology

Answer 4

uncommon
More common in 20-40 years
More common in FEMALE
Afro-Caribbean affected more frequently and severely UK 16/100 0000

Question 5

Symptoms and Signs

Answer 5

In 20–40%, the disease is discovered incidentally, after a routine CXR, and is thus asymptomatic

*Acute sarcoidosis often presents with erythema nodosum ±polyarthralgia – usually resolves spontaneous

• General – fever, malaise, ↓weight, bilateral parotid swelling, lymphadenopathy, hepatosplenomegaly
• Lungs – SOB, cough, ↓ETT, chest discomfort (minimal clinical signs, e.g. fine inspiratory crepitations), CXR shows bilateral hilar lymphadenopathy ±fibrosis
• Musculoskeletal – bone cysts (e.g. dactylitis in phalanges), polyarthlagia, myopathy
• ​Eyes – keratoconjuntivitis sicca (dry eyes), uveitis, papilloedema, glaucoma
• Skin – lupus pernio (red–blue in filtrations of nose, cheek, ears, terminal phalanges),erythema nodosum, non caseating granuloma in shins maculopapular eruptions
• Neuro – lymphocytic meningitis, space-occupying lesions, pituitary infiltration, cerebellar ataxia, CN palsies (e.g. Bell’s palsy), peripheral neuropathy
• Heart – arrhythmias, BBB,pericarditis, cardiomyopathy, congestive cardiac failure
• Metabolic – hypercalcaemia, hypercalciuria (renal stones), pituitary dysfunction

Question 6

Investigations

Answer 6

Bloods

• High serum ACE
• High calcium
• High ESR
• FBC - WCC may be low due to lymphocyte sequestration in the lungs
• Immunoglobulins - polyclonal hyperglobulinaemia
• LFTs - high ALP + GGT

24 hr Urine Collection

• Hypercalciuria

CXR

• Stage 0 - may be clear
• Stage 1 - bilateral hilar lymphadenopathy
• Stage 2 - stage 1 with pulmonary infiltration and paratracheal node enlargement
• Stage 3 - pulmonary infiltration and fibrosis

High-Resolution CT Scan

• Check for diffuse lung involvement

Gallium Scan - shows areas of inflammation

Pulmonary Function Tests

• Low FEV1
• FVC shows restrictive picture

Bronchoscopy and Bronchoalveolar Lavage

• High lymphocytes
• High CD4: CD8 ratio

Transbronchial Lung Biopsy (or lymph node biopsy)

• Shows non-caseating granulomas consisting of:
• Epithelioid cells (activated macrophages)
• Multinucleate Langerhans cells
• Mononuclear cells (lymphocytes)