MSK Flashcards
Define giant cell arteritis
Granulomatous inflammation of large arteries, particularly branches of the external carotid artery, most commonly the temporal artery.
One of the aorta + medium to large artery vasculitides
Explain the aetiology / risk factors of giant cell arteritis
Unknown.
Genetic: Associated with HLA-DR4 and HLA-DRB1
Viral infection: parvovirus b19
Both the humoral and cellular immune systems have been implicated in the pathogenesis of GCA.
Pathphysiology:
- Inflammation (dendritic cells recruit monocytes, which differnetiate the macrophages and giant cells)
- Local vascular damage (macrophages produce MMPs)
- Concentric intimal hyperplasia (macrophages and giant cell produce PDGF and VEGF which stimulate intimal proliferation leading to reduced blood flow and ischaemia)
Association with polymyalgia rheumatica (PMR): 40–50% of patients with giant cell arteritis also have PMR.
Summarise the epidemiology of giant cell arteritis
Peak onset 65-70 y/o. Female: male= 2-4:1. Norther european women
Recognise the presenting symptoms of giant cell arteritis
Subacute, over a few weeks
Constitutional symptoms
Fever, weight loss, night sweats
Symptoms of anemia: fatigue and malaise
Headache: scalp and temporal tenderness (pain on combing hair. Jaw and tongue claudication (when eating!).
Visual disturbances : Blurred vision, sudden blindness in one eye (amaurosis fugax=painless temporary loss of vision in one or both eyes and scintillating scotoma ).
Systemic features : Malaise, low-grade fever, lethargy, weight loss, depression.
Symptoms of polymyalgia rhuematica (PMR): Early morning pain and stiffness of the muscles of the shoulder and pelvic girdle (40– 60% of cases are associated with PMR).
Recognise the signs of giant cell arteritis on physical examination
Swelling and erythema overlying the temporal artery.
Scalp and temporal tenderness.
Thickened non-pulsatile temporal artery.
Reduced Visual acuity.
Identify appropriate investigations for giant cell arteritis and interpret the results
ACR criteria (3 of 5 required):
- Age AT ONSET >50
- Headaches
- Abnormalities of temporal arteyr
- Elevated ESR (>50mm/h)
- Histopathaological abnormalities of temporal artery
Blood : raised ESR, FBC (normocytic anaemia of chronic disease).
Temporal artery biopsy : Within 48h of starting corticosteroids. Note that a negative biopsy does not exclude the diagnosis, because skip lesions occur.
Generate a management plan for giant cell arteritis
High dose oral prednisolone (40-60mg/day) to prevent VISUAL LOSS. Begin treatment as soon as temporal arteritis is suspected. Do not wait for a biopsy.
Reduce pred dose gradally according to symptoms adn ESR. Can require for 1-2 years
Low dose aspirin (+PPIs) to prevent ischaemic complications e.g. reduce risk of visual loss, TIAs or stroke.
Osteoporosis prevention (adequate dietary calcium and vitamin D intake, bisphosphonates).
If GCA is complicated by visual loss: IV pulse methylprednisolone (1 g for 3 days) followed by oral prednisolone (60 mg/day, as above).
Annual CXR for up to 10 years to identify thoracic aortic aneurysms. If detected, monitor with CT every 6– 12 months.
Identify the possible complications of giant cell arteritis and its management
Permanent vision loss: ∼ 20–30% if giant cell arteritis is left untreated
Cerebral ischemia (e.g., transient ischemic attack and stroke): < 2% of cases
Aortic aneurysm and/or dissection: ∼ 10–20% of patients
Summarise the prognosis for patients with giant cell arteritis
In most cases the condition lasts for ~2 years before complete remission.
Define sarcoidosis
Multisystem granulomatous inflammatory disorder
an immunologic disorder that results in lots of small nodules forming throughout the body.
Explain the aetiology / risk factors of sarcoidosis
Unknown.
PATHOLOGY/PATHOGENESIS The unknown antigen is presented on the MHC Class II complex of dendritic cells to CD4 (Th1) lymphocytes, which accumulate and release cytokines (e.g. IL-1/IL-2).
This results in formation of non-caseating granulomas in a variety of organs.
RISK FACTORS:
- Environmental risk factors include a prior infection with Mycobacterium tuberculosis and Borrelia burgdorferi (which causes lyme disease), but to be specific, these pathogens are long gone when the autoimmune problem sets in.
- Genetic: African American/family member with sarcoidosis
Summarise the epidemiology of sarcoidosis
Uncommon. More common in 20– 40 year olds, Africans and females. The prevalence is variable worldwide. Prevalence in UK is 16 in 100 000 (highest in Irish women).
Recognise the presenting symptoms of sarcoidosis
Where does it most commonly involve?
Sarcoidosis can involve nearly every organ, but they most often involves hilar lymph nodes which are lymph nodes that are near the point where the bronchi meets the lung.
General: fever, malaise, weight loss, bilateral parotid swelling, lymphadenopathy, hepatosplenomegaly
Lungs: breathlessness, cough (usually unproductive) , chest discomfort. Fine inspiratory crepitations
MSK: Bone cysts (e.g. dactylitis in phalanges), polyarthralgia, myopathy
Eyes: keratoconjuctivitis sicca (dry eyes), uveitis, papilloedema
Skin : Lupus pernio (red– blue infiltrations of nose, cheek, ears, terminal phalanges), erythema nodosum, maculopapular eruptions.
Neurological : Lymphocytic meningitis, space-occupying lesions, pituitary infiltration, cerebellar ataxia, cranial nerve palsies (e.g. bilateral facial nerve palsy), peripheral neuropathy.
Heart : Arrhythmia, bundle branch block, percarditis, cardiomyopathy, congestive cardiac failure.
Recognise the signs of sarcoidosis on physical examination
General: fever, malaise, weight loss, bilateral parotid swelling, lymphadenopathy, hepatosplenomegaly
Lungs: breathlessness, cough (usually unproductive) , chest discomfort. Fine inspiratory crepitations
MSK: Bone cysts (e.g. dactylitis in phalanges), polyarthralgia, myopathy
Eyes: keratoconjuctivitis sicca (dry eyes), uveitis, papilloedema
Skin : Lupus pernio (red– blue infiltrations of nose, cheek, ears, terminal phalanges), erythema nodosum, maculopapular eruptions.
Neurological : Lymphocytic meningitis, space-occupying lesions, pituitary infiltration, cerebellar ataxia, cranial nerve palsies (e.g. bilateral facial nerve palsy), peripheral neuropathy.
Identify appropriate investigations for sarcoidosis and interpret the results
Why would you do a 24-hr urine collection for sarcoidosis?
Stage 0, 1, 2 and 3 on CXR?
What happens to CD4:CD8 ratio on broncheoalveiolar lavage
Blood: SERUM ACE (is a measure of granuloma burden in tissues, product of macrophages), Ca2+ (elevated)
ESR, FBC (WCC may be reduced because of lymphocyte sequestration in the lungs), immunoglobulins (polycloncal hyperglobulinaemia), LFT (raised alkaline phosphatase and GGT)
24hr urine collection for: hypercalcuria
CXR: Stage 0 : May be clear. Stage 1 : Bilateral hilar lymphadenopathy. Stage 2 : Stage 1 with pulmonary infiltration and paratracheal node enlargement. Stage 3 : Pulmonary infiltration and fibrosis.
High-resolution CT scan: For diffuse lung involvement.
67 Gallium scan: Shows areas of inflammation (classically parotids and around eyes).
Pulmonary function tests: # FEV 1 , FVC and gas transfer (showing restrictive picture).
Bronchoscopy and bronchoalveolar lavage: increased lymphocytes with increased CD4: CD8 ratio.
Transbronchial lung biopsy (or lymph node biopsy): Non-caseating granulomas composed of epithelioid cells (activated macrophages), multinucleate Langhans cells and mononuclear cells (lymphocytes).
What happens to WCC in sarcoidosis
WCC may be reduced because of lymphocyte sequestration in the lungs
What are the normal components of synovial fluid analysis
Colour
Leukocytes
%PMNs
Total protein
Glucose
Crystals
Culture
What would you expect to see in a gouty arthritis synovial fluid analysis
Colour- yellow
Leukocytes- raised
%PMNs: raised
Total protein: slightly raised
Glucose: reduced
Crystals: -vely birefringent needle-shaped crysals
Culture: negative
Interpret this synovial fluid analysis:
Color: Yellow/opaque Leukocytes: 100,000 mm3 %PMNs: 75 Total Protein: 4g/dL Glucose: 20g/dL Crystals: None Culture: Gram+ cocci in clusters
This is a typical synovial fluid analysis for septic arthritis or septic bursitis.
Where are the common sites of bursitis
Common sites of bursitis include trochanteric (as in the vignette above) subacromial, olecranon, prepatellar, and infrapatellar bursae.
Outline what happens to the bursa in bursitis
Trauma or repetitive use can irritate the bursa, leading to inflammation and proliferation of the mesothelial cells lining the sac.
Inflammation of the bursa results in the effusion of a clear fluid within the bursal sac.
With prolonged inflammation, the sac gets thickened and may cause erosion on the adjacent bone due to the pressure exerted by the sac.
What might radiographs of bursitis around the greater trochanter show
Radiographs may show some calcification arising from the apex of the greater trochanter.
What is the current vignette typical for
Gradual, dull, and nocturnal pain with poor response to salicylates. Radiograph shows a well-circumscribed, lytic lesion (> 2 cm) with a rim of reactive sclerosis.
Is this benign or malignant?
Osteoblastoma
Benign
This type of tumor is usually a solitary lesion and tends to affect the axial skeleton (m.c., posterior column of the cervical spine). Osteoblastoma is more common in males between 20 to 30 years. Patients present with gradual, dull, and nocturnal pain with poor response to salicylates. In the physical exam, findings may include decreased range of motion and tender and swollen affected area. Patients may also progress to develop a neurological deficit as a result of cord compression.
Differentiate osteoblastoma with an osteoid osteoma
Osteoid osteoma is basically same as osteoblastoma, but >1cm
Well defined bone tunour that is usually located on epiphysis of long bones.
Pt presents with limited range of motion.
Tumour doesn’t have reactive sclerotic rim.
Giant cell tumour (osteoclastoma)
Signs of osteosarcoma on imaging
ill-defined lesion, aggressive periosteal reaction, and cortical destruction
Give 3 extra-articular manifestations of rheumatoid arthritis
Subcut nodules, pulmonary fibrosis and episcleritis
Deformities typically shown in rheum arthritis?
Ulnar deviation of the fingers
Z shaped thumb
Swan neck and boutonniere deformity
Trigger finger
Radial deviation of the wrist
(NOTE THAT THE DIPs ARE SPARED)
Triad for reactive arthritis?
Extra articular features
Uveitis, arthritis and urethritis
(days or weeks after GI/urogenital infection)
Other extra-articular features of reactive arthritis include circinate balanitis and keratoderma blennorrhagicum (BROWN, commonly found on palms and soles)
Define carpal tunnel syndrome
(briefly, what makes up the carpal tunnel)
Mononeuropathy brought on by compression of median nerve in the carpal tunnel.
Flexor retinaculum superiorly, and carpal bones inferiorly
Explain the aetiology / risk factors of carpal tunnel syndrome
Idiopathic (most common)
or
Secondary to:
- Tenosynovitis: overuse, rheumatoid arthritis, other inflammatory rheumatic disease
- Infaltrive disease of the canal/increased soft tissue: Amyloidosis, Myxoedema, myeloma, acromegaly
- Bone involvement in wrist: osteoarthritis, fracture, tumour
- Fluid retention states: pregnancy, nephrotic syndrome
- Other: obesity, menopause, diabetes, end-stage renal disease, gout
Recognise the presenting symptoms of carpal tunnel syndrome
Tingling and pain in the hand and fingers (may be woken up at night)
Weakness and clumsiness or hand
Recognise the signs of carpal tunnel syndrome on physical examination
Sensory impairment to median nerve distribution (first 3.5 fingers)
Weakness and wasting of thenar eminence (abductor pollicis brevis and opponens)
Tinnels sign: tapping carpal tunnel triggers symptoms (think “tapping tinnel”)
Phalen’s test: maximal flexion of the wrist for 1 minute may cause symptoms (think “phalens flexing”
Signs of the underlying cause: hypothyroidism (myxoedema) or acromegaly
Identify appropriate investigations for carpal tunnel syndrome and interpret the results
Diagnostic test of choice:
EMG
USS and MRI (space occupying lesion)
Bloods:
TFTs, ESR.
Nerve conduction stidues not always necessary. Shows impaired median nerve conduction across the carpal tunnel in the context of normal conduction elsewhere
Management of carpal tunnel
Mild- moderate:
Nocturnal wrist splinting in the neutral position. If there is inadequate response: a single injection of methylprednisolone into the carpal tunnel.
Referral to an occupational therapist/carpal bone mobilization.
Moderate to severe CTS refractory to conservative measures: Surgical decompression
Define rheumatoid arthritis
A chronic autoimmune inflammatory condition characterised by symmetrical deforming polyarthritis and extra-articular manifestations
Affects synovial joints
Explain the aetiology / risk factors of rheumatoid arthritis
Gene assocaitions
What causes extra-articular symptoms
Autoimmune condition of unknown cause
HLA DR-1 and HLA DR-4 associations
Ass with Raynaud’s and Sjorgens
During flares, synovial and immune cells increase and granulations from in the synovial membrane, forming a pannus.
The pannus can damage cartilage and soft tissue and erode bone
Cytokines cause extra-articular symptoms
Summarise the epidemiology of rheumatoid arthritis
3x more likely in females.
Peak incidence 30-50 years
Recognise the presenting symptoms of rheumatoid arthritis
Gradual (occasionally rapid) onset.
Usually affects peripheral joints symmetrically (occasionally monoarticular involvement, e.g. knee).
Pain, swelling and loss of mobility at affected joints
-Fever, fatigue, loss of appetite (–> weight loss)
Morning stiffness that improves as the day goes on
Recognise the signs of rheumatoid arthritis on physical examination
Which joints affected. Which joint is late to be affected
SEE EXTRA-ARTICULAR MANIFESTATIONS BELOW
Articular manifestations:
HAND: MCPs and PIPs usually affected, DIPs SPARED (not much synovium there)*. These lead to reduced grip strength
FEET: Metatarsophalangeal joints affected. Causes people to bear less weight on their toes, and more on their heal. So when they walk they hyperextend their toes.
Elbows, shoulders, knees, ankles can be affected.
Hip can be affected leading to groin, thigh and lower back pain. This is usually a late joint to be affected.
- Ulnar deviation of the fingers at MCP joints (due to subluxation)
- Swann neck deformities and boutonnieres deformity
- Z thumb
- Radial deviation at the wrist
- Trigger finger
- Wasting of the small muscles of the hand, palmar erythema
Identify appropriate investigations for rheumatoid arthritis and interpret the results
What is shown on xray of joints? DENS
What is needed for diagnosis?
What exactly is rheumatoid factor?
Which is the most specific biomarker?
FBC: Hb (reduced), platelets (increased), mild high WCC
ESR&CRP
Autoantibodies: rheumatoid factor (monoclonal IgM against Fc portion of IgG) present in 70% of people with rheumatoid, and 5% of normal population
and anti-CCP, possible anti-nuclear antibodies too
* Anti-citrullinated peptide (anti-CCP) antibodies (C) levels are the most
specific investigation for rheumatoid arthritis.*
However, rheumatoid factor should be tested for, and then anti-CCP is subsequently sent if rheumatic factor is negative, or to infrom decision making about starting therapy
Joint aspiration (acutely) to exclude septic arthritis
Bilateral plain radiographs of hand, wrist and feet (to minor disease progression): DENS
- reduced bone Density
- bone Erosions
- Narrowing of joint space
- Soft tissue swelling
DIAGNOSIS:
- At least 6 weeks
- At least 3 joints
- Positive rheumatoid factor or anti-CCP
- Raised CRP or ESR.
There is also a classification for diagnosis which you need to score above 6 on.
What is the primary cause of mortality associated with rheumatoid arthritis
Cardiovascular disease. Vasculitis and atheromatous plaques (–> MI and strokes)
What is the primary cause of mortality associated with rheumatoid arthritis
Cardiovascular disease. Vasculitis and atheromatous plaques (–> MI and strokes)
What are the extra-articular features of rheumatoid
EXTRA-ARTICULAR
-Fever, fatigue, loss of appetite (–> weight loss)
- Vasculitis and atheromatous plaques (–> MI and strokes)
- Vasculitis of skin: nail fold infarct, digital gangrene, ulcers, purpuric rash
- Heart: pericarditis, pericardial rib, myocarditis, valvular regurg
- Rheumatoid nodules (collections of macrophages and lymphocytes that have a central area of necrosis) on elbows, palms, over extensor tendons
- Low serum iron (increased hepcidin production)
- Pulmonary fibrosis and pleural effusions
- Eyes: scleritis, epislceritis
- Neuro: peripheral neuropathy, carpal tunnel, spinal cord compression
What is felty’s syndrome
Combo of:
- Rheumatoid
- Splenomegaly
- Neutropenia
- Lower limb pigmentation
Define gout
Monoarticular inflammatory arthritis characterised by deposition of monosodium urate crystals in joints, soft tissues and kidneys
Explain the aetiology / risk factors of gout
Purines (from nucleic acids) are usually broken down to uric acid using an enzyme cause xanthine oxidase.
In gout, the plasma becomes saturated with uric acid molecules. These bind to sodium to form monosodium urate, particularly in areas with slow blood flow (joints and kidneys)
RISK FACTOR:
- HYPERURICAEMIA
- Obesity
- Diabetes
- Male
- HTN
- Dyslipidaemia
- Alcohol use
- Drugs
Causes of hyperuricaemia:
1) Impaired excretion from the kidneys
- idiopathic
- renal failure
- medication (CANT LEAP- ciclosporin, aspirin, nicotinic acid, thiazides, loop diuretics, ethambutol, alcohol, pyrizinamide)) - think TB meds!
2) Overproduction of purines
- increased consumption of purine rich foods (shellfish, anchovies and red meat)
- genetic predisposition
- chemo/radiation treatment
3) Rare causes:
- Von gierke disease
- Lesch-nyhan syndrome
Summarise the epidemiology of crystal arthropathy (gout, pseudogout)
Male to female 10:1.
More common in higher social classes
Recognise the presenting symptoms of crystal arthropathy (gout, pseudogout)
ACUTE:
Sudden excruciating monoarticular pain, usually the metatarsophalangeal joint of the great toe
- Crystals cause tissue damage, resulting in a self-limited acute inflammatory episode= GOUT ATTACK.
- A gout attack resolves spontaneously within 10 days
CHRONIC
Persistent low-grade fever, polyarticular pain with painful tophi (urate deposits), best seen on tendons and the pinna of the ear.
- Repeated gout attacks can lead to chronic gout
- This is a type of arthritis in which there is joint tissue destruction and permanent joint deformity
- Permanent deposits of urate crystals= TOPHI
- These tophi can be surrounded by protein which do not therefore trigger inflammatory response, but sometimes the crystals can get out of the protein wall and trigger new gout attacks
Recognise the signs of crystal arthropathy (gout, pseudogout) on physical examination
What is podagra?
What are the 2 main complications
Acute gout: Sudden excruciating monoarticular pain in MTP of big toe, usually symmetrical.
Joints of ankle, knees, wrist and elbow can be involved.
Joint swollen, warm and red.
WHEN IT INVOLVES BIG TOE=PODAGRA. Can wake them up from sleep.
Chronic gout: low grade fever
COMPLICATIONS:
- Urate nephropathy
- Uric acid renal calculi
Identify appropriate investigations for crystal arthropathy (gout, pseudogout) and interpret the results
Synovial fluid analysis:
- Diagnosis depends on presence of monosodium urate crystals:
- Needle shaped, negatively birefrigent under polarised light.
(this means they are yellow under parallel light and blue under perpendicular light)
Gram stain and culture to exclude infection
Blood: FBC (raised WCC), U&E, increased urate (but may be normal in acute gout), raised ESR
AXR/KUB film: uric acid renal stones often radiolucent
Outline how chemo/radiation therapy can cause gout
Lots of tumour cells die due to these therapies, leading to tumour lysis syndrome
Dead cells release their contents into the bloodstream including uric acid (as well as phosphate and potassium)
How does von girke disease cause gout
Glucose 6 phosphatase deficiency means that pyruvate accumulates, preventing conversion of lactate –> pyruvate. Lactate and urate are excreted in the kidneys by the same transporter, so the excess lactate causes reduced urate excretion)
How does lesch-nyhan syndrome lead to gout
It causes deficiency of HGPRT, an enzyme used in the recycling of uric acid (to convert it back into purine)
What are the precipitants of a gout attack
Big meal with purine rich foods (meat, shellfish, anchovies)
Alcohol (as it competes with uric acid for excretion in the kidneys)
Infection
Define pseudogout
What crystals
Inflammatory condition causing pain in the
Calcium pyrophosphate
Explain the aetiology / risk factors of pseudogout.
What are the associations
Provoking factors
Increased pyrophosphate production by CARTILAGE, leading to LOCAL pyrophosphate supersaturation and deposition of calcium pyrophospahte crystals.
SHEDDING of crystals into joint cavity precipitates acute arthritis.
Accumulate in the joints and soft tisuse where they can cause tissue damage.
Idiopathic. Cause not well understood like in gout
Most causes of joint damage predispose to pseudogout (e.g. osteoarthritis, trauma)
Associated with:
- Trauma to joint
- Hyperparathyroidism
- Hypermagnesaemia
- Hypothyroidism
- Hypophosphataemia
- Haemochromatosis
Provoking factors:
-Intercurrent illness, surgery, local trauma
Summarise the epidemiology of pseudogout
Associated with those over >50
Female to male is 2:1.
Recognise the presenting symptoms of pseudogout
Affected joints?
ACUTE ATTACK:
-Painful, swollen, warm and red (indistinguishable from acute gout)
But CPPD tends to affect >1 joint. Knee, shoulder, elbow and wrist.
CHRONIC DEGENERATION:
Joint destruction and limited joint mobility. Pain stuffness, functional impairment
Uncommon: tendonitis, tenosynovitis, bursitis
Recognise the signs of pseudogout
Acute arthritis: Red, hot, tender, restricted range of movement, fever.
Chronic arthropathy (similar to osteoarthritis): Bonyswelling, crepitus, deformity, e.g. varus in knees, restriction of movement.
It is associated with chondrocalcinosis
Identify appropriate investigations for pseudogout
What can you see on x ray
Synovial fluid analysis
CPPD not as evident as monosodium urate:
-Weakly positively birefringent under polarised light
(blue under parallel light, yellow under perpendicular light)
-Rhomboid/rod shaped appearance
-Seen in or outside the cell
Imaging can help:
- CHONDROCALCINOSIS on x ray. This can be occur even if the disease is not clinically active at the time of presentation
- Loss of joint space, osteophytes, subchondral cysts, sclerosis
Blood: FBC (may show increased WCC in acute attack), ESR (may be raised), blood culture (exclude infective arthritis)
Screen for:
- Hyperparathyroidism
- Hypermagnesaemia
- Hypothyroidism
- Hypophosphataemia
- Haemochromatosis
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Reiter’s disease is also known as reactive arthritis. What is the clinical triad
A sterile synovitis
that typically follows an infection and involves the classical triad of
urethritis, arthritis and conjunctivitis.
Which MSK condition affects the DIP more than the PIP
Primary nodal osteoarthritis
Pain is characteristically worse at the end of the day.
In what age group does polymyalgia rheumatica
It’s rare under 60s
T/F paget’s disease does not affect serum Ca2+ levels
T
Ankylosing spondylitis is associated with which HLA
sacroiliac pain that is worst in the morning and better with activity. It also
causes
Schobers test in ank spond?
Schober’s test will reveal reduced spinal flexion.
What is the straight leg raise. When is it positive
The straight
leg raise is a clinical test that elicits pain in patients with lumbar disc herniation.
Osteoarthritis bony swellings?
(Heberden’s and Bouchard’s
nodes).
What % of patients with psoriasis develop arthritis
5%
What is the presentation of psoriasic arthritis
The pattern of arthritis is variable but most commonly affects the distal
interphalangeal joints and is asymmetrical.
Nail or skin changes of
psoriasis are usually present, but may develop after the arthritis.
It is also
important to note that psoriatic arthritis may present as a symmetrical
polyarthritis, resembling rheumatoid arthritis.
What is it called if the psoriatic arthritis turns into marked joint deformity
A small number of patients
with psoriatic arthritis may develop arthritis mutilans, where peri-articular
osteolysis and bone shortening occur, producing marked deformity.
Define sarcoidosis
Immunological disorder that results in lots of nodules forming over the body
Multisystem, granulomatous inflammaotry disorder
Explain the aetiology / risk factors of sarcoidosis
T cell proliferation without a pathogen
Forms nodules which contain granulomas. They have macrophages at the centre and T cells around the pathology, which are NON-CASEATING. The macrophages in the centre can merge together to form a Langerhans giant cell.
Trigger not known
Genetic:
- African American
- Family members with sarcoidosis
Environmental
-Prior infection with Mycobacterium tuberculosis and Borrelia burgdorferi
(these pathogens are long gone when the autoimmune system sets in)
Can involve nearly any organ.
Most commonly involves:
-Hilar lymph nodes, which can cause hilar lymphadenopathy
Can also form in:
- Skin (erythema nodosum, commonly on the front of the shins). Red, hard and painful
- Uveitis (inflammation in the pigmented layer in the eye)
- Heart (can lead to arrhythmia)
Summarise the epidemiology of sarcoidosis
African american females
Uncommon.
More common in 20-40 year olds
Recognise the presenting symptoms of sarcoidosis
GENERALISED:
-Fever, weight loss, fatigue, lymphadenopathy, bilateral parotid swelling, hepatosplenomegaly
SPECIFIC:
- LUNG: SoB/coughing (unproductive), fine inspiratory creps
- MSK: bone cysts (dactylitis in phalanges), polyarthralgia, myopathy
- EYES: Keratoconjunctivitis sicca (dry eyes), uveitis, papilloedema.
- SKIN: Erythema nodosum, maculopapular eruptions, Lupus pernio (red–blue infiltrations of nose, cheek, ears, terminal phalanges)
- NEURO: Lymphocytic meningitis, space-occupying lesions, pituitary infiltration, cerebellar ataxia, cranial nerve palsies (e.g.. bilateral facial nerve palsy) , peripheral neuropathy
- HEART: arrhythmias, BBB, pericarditis, cardiomyopathy, congestive cardiac failure
Recognise the signs of sarcoidosis on physical examination
..
Identify appropriate investigations for sarcoidosis and interpret the results
CHEST X-RAY or CT scan of chest. BILATERAL, HILAR LYMPHADENOPATHY
Blood test:
- Raised calcium (due to excess vit D produced by macrophages)
- Increased ACE (produced by T cells)
- Increased ESR
- WCC may be low due to lymphocyte sequestration in the lungs
- immunoglobulins (polyclonal hyperglobulinaemia),
- LFT (raised alkaline phosphatase and GGT).
Bronchoalveolar lavage:
-Increased T cells in the lung (increased CD4:CD8 ratio)
-Langerhans giant cell forms from fused marcrophages, and contain SCHAUMANN BODIES (calcium and protein deposits) and
ASTEROID BODIES
67 gallium scan: areas of inflammation around parotids and eyes
GOLD STANDARD: BIOPSY AND HISTOLOGY:
-Non-caseating granulomas with T cells peripherally and macrophages in the middle. Mutinucleate langerhans cell.
Outline chest x ray staging of sarcoidosis
Stage 0: may be clear
Stage 1: Bilateral hilar lymphadenopathy
Stage 2: Stage 1 with pulmonary infiltration
Stage 3: Pulmonary infiltration and fibrosis.
T/F rheum arthritis is associated with erythema nodosum
F.
It is associated with infection (strep infections, TB), inflammatory disorders (sarcoid, IBD), drugs (oral contraceptive pill).
See derm.
Not rheum arthritis though
Define Sjögren’s syndrome
Inflammation and destruction of exocrine glands (usually salivary and lacrimal).
Can be “secondary” to other autoimmune diseases
Sicca syndrome is aka primary sjorgens syndrome
Explain the aetiology / risk factors of Sjögren’s syndrome
What are the HLA associations
What conditions is is associated with
Gen: HLA-B8, DR3
Enrivon: Recent exocrine gland infection
Ass with:
- Rheumatoid arthritis,
- scleroderma,
- SLE,
- polymyositits and
- organ specific diseases like: PBC, autoimmune hepatitis, autoimmune thyroid disease and MG
Summarise the epidemiology of Sjögren’s syndrome
Male to female around 1:9!!!!
Onset between 15-65 years old
