Sarcoidosis Flashcards
What is sarcoidosis
granulomatous inflammatory multi-systemic disease in which any organ can be affected, although the lungs are the predominantly affected organ
Epidemiology
- Common in Afro-Caribbeans and Scandinavians
- F>M
- There are two spikes in incidence, in young adulthood and again around age 60.
RFs
- Afro-Caribbean and Scandinavian ethnicity
- Young adults: commonly presents at 20-40 years of age
- Female gender
- Family history
What is sarcoidosis defined by?
presence of non-caseating granulomas, which are nodules of inflammation full of macrophages
What type of reaction is sarcoidosis?
type IV hypersensitivity reaction against an unknown antigen. This reaction is uncontrolled.
What is a granuloma?
small nodules with T-cells on the periphery and macrophages in the centre
What does a T cell-mediated immune response cause?
response to an antigenic stimulus attracts other immune cells and causes the formation of granulomas
What does non-caseating mean?
no tissue necrosis at the centre of the granuloma.
What is a Langhans giant cell?
macrophages fuse together to form a single large multi-nucleated cell called a Langhans giant cells
macrophages begin to release local mediators that result in inflammatio
What does sarcoidosis involve?
- nearly every organ
- Most often:
- hilar lymph nodes which are near the point bronchi meets the lungs
Signs of sarcoidosis
- Cervical and submandibular lymphadenopathy
- Lupus pernio: a lupus-type rash
- Erythema nodosum: dusky coloured nodules on the shins
Symptoms of sarcoidosis
- Cough: non-productive
- Dyspnoea: gradual onset
- Polyarthralgia
-
Uveitis:
- Red-eye
- Photophobia
- Constitutional symptoms: swinging fever, fatigue, weight loss
Acute vs insidious sarcoidosis
- Acute: presents with features such as a swinging fever, polyarthralgia and erythema nodosum
- Insidious: insidious sarcoidosis is commonly associated with a non-productive cough, dyspnoea and fatigue.
Assosciated syndromes with sarcoidosis
- Lofgren’s syndrome: an acute form of sarcoidosis associated with migratory polyarthritis, erythema nodosum, fever, and bilateral hilar lymphadenopathy; has a very good prognosis
- Heerfordt’s syndrome: causes facial nerve palsy, fever, uveitis and parotitis
- Mikulicz’s disease: bilateral parotid and lacrimal gland enlargement; can also occur due to TB and lymphoma.
Investigations
- CXR:first-line imaging; may show hilar lymphadenopathy or bilateral infiltrates
- Routine bloods:inflammatory markers may be raised, can screen for other organ involvement
- Serum calcium:hypercalcaemia (10%) (due to macrophages in non-caseating granulomas activating vitamin D)
- Angiotensin-converting enzyme (ACE):elevated (but with poor sensitivity (60%) and specificity (70%))
- Serum soluble interleukin-2 receptor: raised
