Editing Vasculitis

Vasculitis - a group of inflammatory disorders that result in inflammation and necrosis of blood vessels with subsequent impairment of blood flow resulting in ischaemia and infarction of distal tissues.

== Presentation ==

* Large-vessel vasculitis: limb claudication, vascular bruits, asymmetric blood pressures, or absence of pulses
* Medium-vessel vasculitis: cutaneous nodules and ulcers, livedo reticularis, digital gangrene, mononeuritis multiplex, and renovascular hypertension
* Small-vessel vasculitis: palpable purpura, pulmonary-renal syndromes, urticarial skin rashes, and scleritis


== Histologic findings: ==

* Characteristic - infiltration of vessel wall by neutrophils/mononuclear cells/giant cells; fibrinoid necrosis with pan-mural destruction of the vessel wall; leukocytoclasis
* Peri-vascular infiltration alone is quite non-specific and not necessarily reflective of vasculitis

== '''Large-vessel vasculitis:''' ==

* '''Takayasu arteritis'''
* '''GCA/Temporal arteritis'''
** Epidemiology
*** Primarily >50yo, and increasing with age
*** Mostly caucasians
*** F:M 2:1
** Pathophysiology
*** Exact cause unknown
*** Probably in response to immunologic injury, the artery induces myofibroblasts which leads to new vessel formation and marked thickening of intima
*** This leads to vessel occlusion leading to symptoms of ischaemia
** Clinical
*** New-onset headache
*** Scalp tenderness
*** Reduced pulse and tenderness along temporal artery
*** Jaw and tongue claudication (specific)
*** Diplopia (specific)
*** Blindness
*** Systemic inflammation
*** PMR (although only 10-20% of patients with PMR develop GCA)
*** Check for bilateral pulses and BPs - 20% have large-vessel vasculitis
*** ICA and vertebral arteries can be involved, leading to stroke/seizure/acute hearing loss/vertigo/cerebral dysfunction and depression
** Diagnosis
***
*** Gold standard test if temporal artery biopsies
**** Up to 50% of biopsies show diffuse lymphocytic infiltrate without evidence of granulomatous inflammation or giant cells
**** Fraying of the internal elastic lamina is a non-specific finding of normal aging, and should be ignored in the absence of inflammation
** Medical treatment
*** Corticosteroid therapy - 40-60mg daily, maintaining the dose until inflammatory markers normalise
**** Reduce prednisolone by 5mg every 1-2 weeks down to 30mg/day, then 2.5mg every 1-2 weeks until 15mg per day, then 2.5mg every 4 weeks until 10mg, then 1mg every 4 weeks until the patient is off prednisolone
*** IV methylpred if visual loss is present for 3 days
*** Start on low-dose aspirin to reduce risk of cardiovascular events and blindness
** Surgical treatment
*** Revascularisation is rare required
* '''Idiopathic aortitis'''
** '''Idiopathic retroperitoneal fibrosis'''
*** Presents 40-60yo
*** Pain in lower back, abdomen, flank and scrotum
*** Some have systemic symptoms
*** Most have elevated inflammatory markers
*** CT - homogenous mass around the aorta following the iliac bifurcation, with medialisation of ureters and associated hydronephrosis. Usually, lymphadenopathy is absent.
*** Pathophysiology unknown
*** Treat with high-dose prednisolone
** '''IgG4-related systemic disease'''
** '''Erdheim-Chester disease'''
*** Periaortic fibrosis ('coated aorta')
*** Hairy kidney
*** Main distinguishing factor from RPF/IgG4 is that bones are involved

== '''Medium-vessel vasculitis''' ==

* Polyarteritis nodosa
** Pathophysiology
*** Necrotising vasculitis or small and medium arteries
*** Characterised by the absence of glomerulonephritis and absence of ANCA antibodies
*** Can be idiopathic or secondary to HBV infection or other viral infections
*** Also seen as a paraneoplastic manifestation of haematology malignancy
** Diagnosis
***
** Presentation
*** Constitutional symptoms and organ dysfunction - see above
* '''Thromboangitis obliterans (Buerger disease)'''
** See separate topic)
* '''Kawasaki disease'''
** Acute vasculitis
** Typically seen in children
** Involvement of small/medium arteries, especially coronary arteries
** Main cause of death is MI
** Treat with high-dose aspirin and IVIg

== '''Small-vessel vasculitis''' ==

* '''Antineutrophil cytoplasmic antibody-associated vasculitis'''
* '''Granulomatosis with polyangiitis'''
** Previously Wegener granulomatosis
** Granulomatous vasculitis of the upper and lower respiratory tract
** Also causes pauci-immune focal, segmental, crescentic glomerulonephritis
** Clinical presentation
*** Chronic sinusitis
*** Epistaxis
*** Chronic purulent nasal drainage
*** Chronic inflammation of the auditory canal - acute suppurative otitis media and chronic serous otitis media
*** Hoarseness, subglottic stenosis
** Investigations
*** 90% ANVA positive
** Treatment - steroids
* '''Microscopic polyangiitis'''
** Systemic necrotising vasculitis of small vessels
** Associated with ANCA formation
** No granulomas
* '''Eosinophilic granulomatosis with polyangiitis'''
** Previously known as Churg-Strauss syndrome
** Associated with eosinophilia - 70% of patients have a history of some sort of atopic disease

== '''Vasculitis secondary to connective tissue disease''' ==

* Behcet disease
** Systemic vasculitis of unknown aetiology 
** Classically presents with oral and genital ulcers, uveitis, skin lesions, vascular manifestations
** Vascular manifestations - aneurysms at unusual locations (especially pulmonary arteries), arterial and venous thrombosis including Budd-Chiari syndrome
* SLE
** Chronic multisystem autoimmune disease characterised by autoantibodies to various nuclear antigens
** Vasculitis occurs in 30% of SLE patients - most commonly affects small vessels of the skin
** Tender punctate lesions on fingertips and palms
** Inflammatory vasculitis in SLE merits escalation of therapy with steroids and DMARDs
** Ischaemic events related to the antiphospholipid syndrome may mimic vasculitis in SLE, and should be considered when SLE patients present with digital and skin ulcerations
* Rheumatoid vasculitis
* Relapsing polychondritis
* Cogan syndrome
* Pseudoxanthoma elasticum
* Exercise-related external iliac arteriopathy

== Vascular mimics ==

* Fibromuscular dysplasia
** Non-inflammatory vascular disease, most commonly affecting the carotid and renal arteries, but can affect any vascular bed
* Radiation arteritis
** Particularly common in carotid arteries
** Reasonable results from stenting
* Neurofibromatosis type 1
** Autosomal dominant disorder that results in a loss-of-function mutation of the tumour suppressor gene NF-1
** Neurofibromas, schwannomas, phaechromocytomas
** Vascular lesions are rare but can resemble FMD
* Drug-induced vasculitis
** Chemotherapeutic agents, growth factors, interferons, antithyroid drugs, hydrochlorothiazide, hydralazine, minocycline, penicillamine, vaccines

== Vasculitis affecting GIT ==

* Presentation
** Mesenteric ischaemia
** Ischaemic colitis
** NOMI
** Strictures
** Ischaemic hepatitis
* When to suspect
** Patients with symptoms of bowel ischaemia, but no risk factors for macrovascular disease
* Diagnosis
** Specific serologic testing
** CT angiogram will usually pick something up

== '''Aortitis''' - ==
'inflammatory aortic conditions that cannot be attributed to atherosclerosis alone.'

'''Periaortitis''' - 'inflammatory process arising from the adventitia of the aortic wall and extending into the surrounding periaortic space'. Mostly affects lower abdominal aorta and CIAs. Consider idiopathic retroperitoneal fibrosis.

* Clinically - usually back or flank pain, which is usually persistent, not exacerbated by movement or palpation. It transiently responds to NSAIDs. Ureteral symptoms can ensue.

Pathophysiology

* Involves the media and/or intima, and sometimes the adventitia too

Aetiology

* Infectious
** Septic emboli (typically infective endocarditis)
** As a complication of bacteraemia
** Most commonly Salmonella, Staphylococci and Pneumococci
** Can be bacterial, viral or fungal
* Non-infectious (far more common)
** Large-vessel vasculidites
*** GCA
*** Takayasu arteritis
** Complication of many rheumatological diseases
*** ANCA-associated vasculitis
*** SLE
*** RA
*** Ankylosing spondylitis
*** Behcet disease




Retroperitoneal fibrosis:
[[Category:Vascular]]