14. Autoimmune MSK

Question 1

What is sarcoidosis?

Answer 1

Chronic granulomatous disorder of unknown cause. Characterised by T lymphocytes and macrophages driving non-caseating granuloma formation (no necrosis in granulomas).

Question 2

How does sarcoidosis present?

Answer 2

Fever
Erythema nodosum
Polyarthralgia
Bilateral hilar lymphadenopathy
Pulmonary - dry cough and progressive dypnoea
Extra pulm - organomegaly, uveitis, LUPUS PERNIO, subcut nodules, arrhythmia, symptoms of hypercalcaemia

Question 3

Investigations for sarcoidsosis?

Answer 3

Increased ESR
Lymphopenia
Hypercalcaemia from high neutrophils
Raised ACE!! Very specific as lung damage

CXR -
Stage 1 - bihilar lymphadenopathy
2 - BHL and infiltrates
3. infiltrates alone
4. extensive fibrosis

Biopsy diagnostic

Question 4

How to treat sarcoidosis?

Answer 4

Conservative

High dose corticosteroids

Question 5

What is SLE?

Answer 5

Wrongful response to host that causes immune complex formation with poor clearance. Type III hypersensitivity reaction.
Related to HLA-DR3

Question 6

How does SLE present?

Answer 6

Malar or discoid rash
Photosensitive rash
Oral ulcers
Arthritis
Serositis (pleuritis or pericarditis)
Renal disorders
Neuro disorder
Haem

Question 7

SLE Investigations?

Answer 7

Anaemia, lymphopenia, thrombocytopenia
Raised ESR but normal CRP
ANA, anti-dsDNA and antihistone

C3 and C4 depletion

Question 8

SLE Treatment?

Answer 8

Maintain with NSAIDS and hydroxychloroquine

Mild - low dose steroids
Moderate - DMARDS
Severe - high dose steroids

Question 9

What is sjorgren’s syndrome?

Answer 9

Chronic inflammatory disorder characterised by lymphocytic infiltration and destruction of exocrine glands

Question 10

How does sjorgren’s present?

Answer 10

Keratoconjunctivitis sicca - dry eye
Xerostomia - dry mouth
Parotid swelling
Polyarthritis
Raynaud's
Vasculitis

Question 11

Investigations for Sjogren’s?

Answer 11

Schirmer’s test
Autoantibodies - anti-ro and anti-la but not specific
Salivary gland biopsy diagnostic

Question 12

Treatment for Sjogren’s?

Answer 12

Dry eye - eye drops
Dry mouth - salivary substitutes
Severe disease - immunosuppressants e.g. steroids

Question 13

What is systemic sclerosis?

Answer 13

Multisystemic autoimmune disease by abnormalities in non-inflammatory bloods vessels, fibrosis of skin and internal organs.

Question 14

What are the types of systemic sclerosis?

Answer 14

Limited - hands, face and feet

Diffuse - wide spread organ involvement

Question 15

How does systemic sclerosis present?

Answer 15

Puffy, taut skin with no wrinkles
Renal scleroderma
Pulmonary fibrosis
GI reflux, dysmotility

Question 16

Investigations for systemic sclerosis

Answer 16

Anti-centromere in limited

Anti-scl-70 and anti-rna polymerase for diffuse

Question 17

How to manage systemic sclerosis?

Answer 17

Suppress immune system and treat symptoms

Question 18

What is poly/dermatomyositis?

Answer 18

Rare condition characterised by onset of progressive, symmetrical proximal muscle weakness. Often associated with paraneoplastic phenomena e.g. ovarian cancer

Question 19

Polymyositis pathology?

Answer 19

Endomysial inflammation with CD8+ T cells

Question 20

Dermatomyositis pathology?

Answer 20

Perimysial inflammation with CD4+ T cells

Question 21

How does polymyositis present?

Answer 21

Progressive symmetrical muscle weakness

Question 22

How does dermatomyositis present?

Answer 22

Gottron’s papules
Facial erythema
Shawl rash
Mechanics hands - dark, thick, irregular patches

Question 23

How do we investigate poly/dermatomyositis?

Answer 23

Muscle enzymes - CK and aldolase
EMG
Muscle biopsy - inflammation
Autoantibodies - anti-srp, anti-mi2 and anti-jo1

Question 24

What is giant cell arteritis/temporal arteritis?

Answer 24

Large vessel granulomatous vasculitis of external carotid artery branches
Usually comes hand in hand with PMR

Question 25

What is polymyalgia rheumatica?

Answer 25

Inflammatory condition manifesting as pain and morning stiffness of neck, shoulder and hip girdle

Question 26

How does GCA present?

Answer 26

``` Unilateral headache Scalp tenderness Tongue/jaw claudication Amaurosis fugax Unilateral blindness ```

Question 27

How does PMR present?

Answer 27

Subacute onset of bilateral aching, tenderness and morning stiffness Fever Weight loss Anorexia

Question 28

How do we investigate GCA?

Answer 28

ESR, CRP FBC - normocytic anaemia Biopsy after managed to confirm

Question 29

How do we investigate PMR?

Answer 29

ESR | CRP (sensitive)

Question 30

How do we treat GCA?

Answer 30

High dose methylprednisolone if blindness starting | Normal pred if before blindness

Question 31

How do we treat PMR?

Answer 31

Rapid response to steroids within a week | Bone protection if steroids needed for 2+ years

Question 32

What is Behcet's disease?

Answer 32

Systemic inflammatory vasculitis associated with HLA-B51

Question 33

How does behcet's present?

Answer 33

Recurrent aphthous ulcers Genital ulcerations Erythema nodosum

Question 34

How do we investigate behcet's disease?

Answer 34

Usually clinical diagnosis | Can do pathergy testing (needle in forearm, papule forms in 48 hours)

Question 35

How do we manage behcet's?

Answer 35

Orogenital ulceration - topical steroids | Organ involvement - steroids plus immunosuppressant (azathioprine)

Question 36

What is polyarteritis nodosa?

Answer 36

Necrotising inflammation of medium sized arteries without vasculitis in arterioles, venules or capillaries.

Question 37

How does polyarteritis nodosa present?

Answer 37

``` Systemic features Skin - rash, ulcers, nodules Renal - stenosis, ischaemia, HTN Cardio GI - pain, melaena Livedo reticularis ```

Question 38

How do we investigate polyarteritis nodosa?

Answer 38

``` FBC - elevated WCC HBV - positive HbsAg potentially ESR, CRP MRA - string of pearls appearance Renal biopsy ```

Question 39

How do we treat polyarteritis nodosa?

Answer 39

Prednisolone