sarcoidosis Flashcards
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Sarcoidosis is a multisystemic inflammatory disorder of unknown etiology characterized by the accumilation of non-caseating epithelioid granulomas in involved organs
epi
20-40 y/o
F > M
geo: afrocaribbean
HLA-DRB1 + DQB! alleles
Features
acute: erythema nodosum [painful erythematous nodules on shins], bilateral hilar lymphadenopathy, swinging fever, polyarthralgia, uveitis/keratoconjunctivitis sicca
insidious: dyspnoea, non-productive cough, malaise, weight loss
skin: lupus pernio [dusky raised purple plaque on nose, cheek, fingers]
hypercalcaemia: macrophages inside the granulomas cause an increased conversion of vitamin D to its active form (1,25-dihydroxycholecalciferol)
- renal stones
- nephrocalcinosis
heart: restrictive cardiomyopathy 2ry to granulomas + fibrosis, pericardial effusion
- Many patients are asymptomatic.
- Symptom and disease progression occurs in 10-20% of patients – this usually involves a decline in lung function.
- It can also cause a whole range of other non-pulmonary symptoms, making sarcoidosis a differential diagnosis for almost any unidentifiable disease! Examples include, Hepatomegaly, splenomegaly, lymphadenopathy, Bell’s palsy, uveitis, conjunctivitis and cataracts.
what is a granuloma
- A granuloma is a collection of WBC’s (mononuclear cells and macrophages) , surrounded by lymphocytes, plasma cells, mast cells, fibroblasts, and collagen.
- They can occur in any organ, but in sarcoidosis most commonly occur in the lung and lymphatics.
- In the lung they tend to be distributed along the line of lymph nodes – Hence the association of sarcoidosis and hilar CXRchanges
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- a detailed history from the patient - inquire about
- any extrapulmonary symptoms which may relate to skin, eyes, and joints involvement
- occupational and environmental dust exposure - may indicate hypersensitive pneumonitis
- family history of sarcoidosis (1)
- physical examination
- should be carried out according to the symptoms
- identify any possible biopsy sites e.g. - lymphadenopathy, skin lesions, old scars, and tattoos
- chest radiology
- CXR is often used to stage the condition
Stage 0 – normal CXR
Stage 1 – BHL – bilateral hilar lymphadenopathy
Stage 2 – BHL + Infiltrates
Stage 3 – Peripheral pulmonary infiltrates alone
Stage 4 – Progressive pulmonary fibrosis ± bulla (honeycombing on CXR).
- lung function tests - may show reduced transfer factor, reduced FVC and a restrictive ventilatory defect
- blood tests
- full blood count
- liver function test
- serum (and urinary) electrolytes and calcium - hypercalcaemia and hypercalciuria are common
- serum angiotensin converting enzyme (ACE) - may be raised in acute sarcoidosis, however, the low specificity of the test renders it useful only for monitoring the severity of disease (1)
- ECG - findings suggestive of latent cardiac sarcoidosis are arrhythmias and conduction delay (3)
- tuberculin tests up to 1 in 100 are negative in 75% of patients
- ophthalmology review - slit lamp examination to recognize symptomatic and potentially sight threatening uveitis (1)
- high resolution CT
- is a standard investigation in hospital setting and can be used to assess the involvement and to identify abnormal nodes for biopsy (1).
- may reveal the presence of parenchymal disease, not revealed by a chest radiograph
- tissue biopsy: see non caseating granuloma
- samples: lymph nodes, bronchial, transbronchial, liver, skin, eyelids and muscle
- transbronchial samples are histologically positive in 90% of patients with pulmonary sarcoidosis
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- Patients with asympto BHL dont need rx
- acute sarcoidosis- usually resolves spontaneously, bed rest + NSAIDs
- chronic sarcoidosis- need steroids
Indications for steroids
- patients with chest x-ray stage 2 or 3 disease who have moderate to severe or progressive symptoms. Patients with asymptomatic and stable stage 2 or 3 disease who have only mildly abnormal lung function do not require treatment
- hypercalcaemia
- eye, heart or neuro involvement
- Very severe cases may require further intervention, including:
- IV methyprednisolone
- Immunosuprressants – e.g. cyclosporine, methotrxate, cyclophosphamide
prognosis
generally good prognosis
spontaneous remission is seen in within 6 mo of rx
- 55–90% of patients with stage I radiological disease
- 40–70% with stage II disease
- 10–20% with stage III disease
- 0% in stage IV disease
overall mortality in sarcoidosis is estimated to be around 1–5% , majority are due to pulmonary, myocardial or CNS involvement (3)
as many as 10% will become disabled by pulmonary fibrosis
BHL ddx
sarcoidosis
infection- TB, mycoplasma
malignancy- lymphoma, carcinoma
interstitial disease: EAA, silicosis
granulomatous disease differential
- infections- tb, leprosy, syphillis, crypto, schistosomiasis
- autoimmune: PBC
- vasculitis: GCA, PAN, wegener’s, takayasu’s
- idiopathic: crohns, sarcoidosis
- interstitial lung: EAA, silicosis
