Download - Sarcoidosis
Sarcoidosis
DEAPCIT
definition
• Idiopathic, multi-system, chronic granulomatous disease characterised by noncaseating granuloma formation
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
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
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
pathology• Giant cells, epithelioid cells & macrophages in non-caseating
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
Schaumann Bodies
non-caseating granulomas
Asteroid bodies
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
– Nodular, erythematous eruption on anterior LL
– Type IV hypersensitivity reaction
• Constitutional symptoms
• Chronic
– Gradual onset, with relapses
– More organ-specific symptoms, which result from irreversible fibrosis
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
ENT
• Occur in 9%-15% of patient with sarcoidosis• Most common with– Cervical LN– Parotidomegaly– Facial nerve palsy
Laryngeal = 1 – 5%
– Hoarseness, dyspnoea / stridor
– Rarely painful– Early stage = white-
brown mucosal nodules– Later stage = pale,
oedematous epiglottis• Lesser changes in
remaining supraglottis (arytenoids, aryepiglottic folds, false VC)
• Glottis rarely involved
• 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
• 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
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
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
• Laryngeal– Steroids– Intralesional steroid injection– If unresponsive, consider low-dose RTH– Tracheostomy or RTH / laser to obstructing lesions