Sarcoidosis

Question 1

Define sarcoidosis

Answer 1

Multisystem granulomatous inflammatory disorder (lung and lymph node involvement in
>90% of patients)

Question 2

What are the causes/risk factors of sarcoidosis?

Answer 2

Unknown aetiology - ?viruses, Mycobacterium, environmental triggers, genetic factors
MHC II presents unknown antigen to CD4 T cells -> cytokine release -> formation of noncaseating granulomas with multinucleated giant cells

Question 3

What are the signs and symptoms of sarcoidosis?

Answer 3

General
• Fever
• Malaise
• Weight loss
• Bilateral parotid swelling
• Bilateral hilar lymphadenopathy
• Hepatosplenomegaly

Lungs
• SOB
• Cough
• Wheeze

Skin
• Lupus pernio (indurated plaques on face)
• Erythema nodosum (tender erythematous
nodules)

Eyes
• Uveitis
• Keratoconjunctivitis sicca

Joints
• Arthralgia

Neurological
• SOL – headache, seizures
• Pituitary infiltration
• Cranial nerve palsies (facial weakness)
• Peripheral neuropathy

Heart
• Arrhythmia
• Bundle branch block
• Pericarditis

Question 4

What are the investigations for sarcoidosis?

Answer 4

• Bloods - ↑ serum ACE,
calcium and ESR
• CXR - Stage 0: normal
Stage I: bilateral hilar lymphadenopathy
Stage II: bilateral hilar lymphadenopathy plus pulmonary infiltrates
Stage III: pulmonary infiltrates without hilar lymphadenopathy
Stage IV: extensive fibrosis with distortion.
(hilar and/or paratracheal adenopathy with upper lobe predominant, bilateral infiltrates; pleural effusions (rare) and egg shell calcifications (very rare) may be seen)
• HRCT
• Lung function tests
(restrictive)
• Bronchoscopy and
transbronchial biopsy
• FBC - anaemia in 4%-20%; leukopenia in 40%
• serum urea - may be elevated
• creatinine -may be elevated
• liver enzymes - elevated
• serum calcium - hypercalcaemia
• PFTs - restrictive or obstructive or mixed pattern
• ECG - conduction defects
• purified protein derivative of tuberculin (PPD) - negative