1. Sarcoidosis
DEAPCIT

2. definition
• Idiopathic, multi-system, chronic
granulomatous disease characterised by
noncaseating granuloma formation

3. epidemiology
• Prevalence = 50/100 000
• Common in African Americans, not in Africans
living in Africa
• Common in Japan, uncommon in rest of Asia
• Clusters in health workers
• Age = 20 – 40 yrs
• F>M

4. aetiology
• Genetic predisposition + environmental trigger
• Genetic
– Most common allele found in sarcoidosis is HLA-B8
• ? Infectious Ag triggers CMI response & starts
disease process
– Many organisms have been linked to sarcoidosis:
• M Tb
• Mycoplasma species; Borrelia burgdorferi;
Propionibacterium acnes
• Fungi - Histoplasma and Cryptococcus species
• Viruses - EBV, CMV, HSV, hepatitis C virus, and rubella

5. pathophysiology
• May begin with lung alveolitis
• This overstimulated local cellular immune
response may involve overactive TH-cells, which
release chemotactic factors to attract monocytes
from blood to lungs & nose, resulting in chronic
inflammation
• Macrophages transform into giant cells, which
then form epithelioid cells, which form
granuloma
• Mature epithelioid granulomas release ACE

6. pathology
• Giant cells, epithelioid cells & macrophages in noncaseating granulomas, which have fewer lymphocytes
surrounding = ‘naked tubercle’
• Fibrinoid necrosis
• Giant cells have prominent inclusion bodies (e.g. asteroids,
Schaumann)
• Asteroid bodies are star-shaped eosinophilic structures
• Schaumann bodies are round or oval, laminated structures,
which are usually calcified at the periphery
• Granulomas are referred to as ‘naked’ because they only
have a sparse lymphocytic infiltrate at the margins
• Giant cells are larger & have more nuclei than in TB

7. Schaumann Bodies
non-caseating granulomas
Asteroid bodies

8. Clinical (2 patterns)
•
Acute
– Sudden, with remission in 2 years
– More common in Caucasians
– May present with Lofgren’s Syndrome
•
•
•
•
Bilateral hilar LN
Ankle arthritis
Erythema nodosum
•
Constitutional symptoms
–
–
Nodular, erythematous eruption on anterior LL
Type IV hypersensitivity reaction
Chronic
– Gradual onset, with relapses
– More organ-specific symptoms, which result from irreversible fibrosis

9. Course of disease
• Asymptomatic (30-50%)
• Constitutional Symptoms (30%)
• Organ-Specific Symptoms (20-40%)
– Lung LN (90%, 30% symptomatic)
– LN = 30%
– splenomegaly in 40 – 80%
– Skin = 25%
– Eye = 20 – 30%
– Neuro = < 10%
– Cardiac = 5%
– GIT
– Renal

10. ENT
• Occur in 9%-15% of patient with sarcoidosis
• Most common with
– Cervical LN
– Parotidomegaly
– Facial nerve palsy

11. Laryngeal = 1 – 5%
– Hoarseness, dyspnoea /
stridor
– Rarely painful
– Early stage = whitebrown mucosal nodules
– Later stage = pale,
oedematous epiglottis
• Lesser changes in
remaining supraglottis
(arytenoids, aryepiglottic
folds, false VC)
• Glottis rarely involved

12. • Sinonasal = 10%:
– NOT often presenting
symptom
– Nasal obstruction,
rhinorrhoea, PND
– Anosmia, recurrent sinusitis,
epiphora
– Firm, raised subcutaneous
yellow papule on nose, may
become confluent
– Diffuse nasal crusting & thick
mucous
– Submucosal nodules on
septum & IT, with dry friable
mucosa
• Sarcoidosis interferes with
submucosal gland function,
causing dryness
– Septal perforations & polyps
– Rarely, granulomas may
erode through palate
• Ear - rare
– Pinna = nodules
– ME = ET obstruction from NP
involvement
– SNHL < 1% = sudden,
asymmetric, fluctuating, high
or low frequency
– Permanent loss or complete
recovery
– Vestibular involvement
recovers less well than
acoustic
– Vestibulo-acoustic
involvement is often
concurrent with facial palsy &
uveitis

13. • Oropharyngeal
– Tonsils in 2%
– Pharyngeal & oesophageal
stenosis may result from fibrosis
• Neurosarcoid = 5%
– CN > CNS symptoms (e.g.
pituitary involvement causes DI)
– Basal Granulomatous Meningitis
• Causes multiple cranial
neuropathies by involvement of
nerves with perivascular
lymphocytic infiltrates in IAC,
causing fluctuating ischaemia
• Facial > optic > glossopharyngeal
> vagus > cochlear nerves
– TV channels + 8
• Fluctuating ischaemia of facial
nerve caused by perivascular
lymphocytic infiltration
proximal to geniculate ganglion,
leads to reversible neuropraxia –
often sudden, bilateral palsies,
which resolve
• Cervical LN = 50%
– FNA has high yield
• Parotidomegaly = 6%
– Usually bilateral & FNA is
useful
– Heerfordt’s disease
(Uveoparotid Fever)
• Uveitis, parotitis, facial
paralysis, fever

14. Investigation
• Biopsy
– Submucosal nodules or transbronchial lung, LN, lip gland
– histopath, AFB, culture
• Bronchoalveolar lavage = elevated CD4:CD8 ratio
• Haematologic
– Ca (serum & urine) = elevated
– Serum ACE
• Correlates with active disease in 40 – 90%
• Used in monitoring
• CXR (respiratory symptoms are most common)
– Bilateral hilar lymphadenopathy & lung infiltrates
• Kveim Test
– Part of a spleen from a patient with known sarcoidosis is injected into skin of a
patient suspected to have the disease
– If granulomas are found (4–6 weeks later), the test is positive

15. Management
• MEDICAL
– Steroids = mainstay
– Systemic steroids in eye / organ involvement
– Topical steroids in skin / eye disease
– Inhaled steroids in URT / LRT disease
– MTX / Azathioprine
• Surgical

16. • Laryngeal
– Steroids
– Intralesional steroid injection
– If unresponsive, consider low-dose RTH
– Tracheostomy or RTH / laser to obstructing lesions