Sarcoidosis Flashcards
Epidemiology of sarcoidosis.
Highest in northern europe.
Usually affects adults aged 20-40 years more common in women.
Associated with HLA-DRB1 alleles.
How is sarcoidosis often detected?
Incidentally on route CXR
Explain the immunopathology in sarcoidosis.
Typical sarcoid granulomas consisting of focal accumulations of epitheloid cells, macrophages and lymphocytes, mainly T cells.
There is a depressed cell mediated reactivity to tuberculin.
Overall lymphopenia but B cells can be raised.
Bronchoalveolar lavage shows a great increase in the overall number of cells.
Define sarcoidosis.
A multisystemic disorder with chronic inflammation and granuloma formation.
Symptoms of sarcoidosis.
The typical MCQ exam patient is a 20-40 year old black woman presenting with a dry cough and shortness of breath. They may have nodules on their shins suggesting erythema nodosum.
Asymptomatic
Fatigue
Weight loss
Aches and pains
Arteritis
Dyspnoea
Dry eyes
Cough
Extertional dyspnoea
Signs of sarcoidosis.
Erythema nodosum
Lymphadenopathy
Rashes
Hepatomegaly
Arrhytmia
Anaemia
Nerve palsy
Common general findings in sarcoidosis.
Bilateral lymph node enlargement
Erythema nodosum in forms of a maculopapular rash
Nodularity of the trachea
Bluish discoloration of nose
Pulmonary infiltration
Uveitis in eyes
Organs involved in sarcoidosis.
Lungs, bronchi and trachea (90%)
Liver (50-80%)
Lymph nodes (70%)
Eyes
Skin (25%)
Heart (30%)
Spleen (18%)
Brain (5%)
What do people with acute sarcoidosis generally present with?
Fever
Erythema nodosum
Polyarthralgia and bilateral hilar lymphadenopathy
This is also called Löfgren syndrome and usually resolves spontaneously.
Non-pulmonary signs of sarcoidosis.
Lymphadenopathy
Hepatomegaly
Splenomegaly
Uveitis
Conjunctivitis
Bell’s palsy
Neuropathy and meningitis
Erythema nodosum
Arrhythmias
Hypercalcaemia
Hypercalciuria
Renal stones
Most common cause of erythema nodosum
Sarcoidosis
Can also be idiopathic or due to bacterial infection.
Explain erythema nodosum.
Usually found in young adult women.
Commonly found on shins and face.
There are bilateral deep tender nodules that are pre-tibial.
The overlying skin is shiny red.
It is called a maculopapular rash.
There can be onset of acute arthralgia, malaise and oedema.
After 2-3 days the lesions flatten and will show up as a bruised appearance.
Diagnostic criteria of sarcoidosis.
Clinical findings
Exclude differentials
Evidence of non-caseating granulomas on lymph node biopsy of bilateral lymph node enlargement.
Differentials of bilateral hilar lymphadenopathy.
Sarcoidosis
TB
Lymphoma
Lung cancer
Investigations of sarcoidosis.
Bloods - ESR, lymphopenia, LFTs, serum ACE, Ca2+, immunoglobulins
24h urine for Ca2+
CXR
HRCT
ECG
PFTs
Tissue biopsy
Bronchoalveolar lavage
USS of kidneys and liver/spleen
Bone x-ray
MRI
Blood findings in sarcoidosis.
Raised serum ACE. This is often used as a screening test.
Raised LFTs
Hypercalcaemia is a key finding.
Raised serum soluble interleukin-2 receptor
Raised CRP
Raised immunoglobulins
24h urine findings in sarcoidosis.
Ca2+ raised
Differentials of raised serum ACE.
Lymphoma
Pulmonary TB
Asbestosis
Silicosis
This makes raised serum ACE supportive but not diagnostic.
ECG findings in sarcoidosis.
May show arrhythmias or bundle branch block.
Radiological stages of sarcoidosis.
Stage 0 - Normal
Stage 1 - BHL
Stage 2 - BHL + peripheral pulmonary infiltrates
Stage 3 - Peripheral pulmonary infiltration alone
4 - Lung fibrosis, bulla formation (honeycomb) and pleural involvement.
Findings on PFTs in sarcoidosis.
May be normal or show redcued lung volumes, restrictive pattern and reduced transfer factors.
What is the diagnostic test of sarcoidosis?
The gold standard for confirming the diagnosis of sarcoidosis is by histology from a biopsy. This is usually done by doing bronchoscopy with ultrasound guided biopsy of mediastinal lymph nodes.
The histology shows characteristic non-caseating granulomas with epithelioid cells.
Eye involvement in sarcoidosis.
Anterior uveitis
Keratoconjunctivitis sicca
Neurological involvement in sarcoidosis.
Cognitive dysfunction
Nodules
Central diabetes insipidus
Headache
Cranial nerve palsies
Mononeuritis multiplex
Peripheral neruopathy
Seizures
