Clinical features of vasculitis on the basis of size of the affected blood vessel
| Size of blood vessel | Blood vessel involved | Clinical features |
| Small vessel vasculitis (vessels smaller than arteries such as capillaries and venules) | Cutaneous post‐capillary venules | Palpable purpura |
| Glomerular capillaries | Haematuria, red cell casts in urine, proteinuria, and decline in renal function | |
| Pulmonary capillaries | Lung haemorrhage manifesting as breathlessness, haemoptysis and widespread alveolar shadowing on chest radiograph | |
| Medium vessel vasculitis (small and medium sized arteries) | Small cutaneous arteries | Necrotic lesions and ulcers, nail fold infarcts |
| Epineural arteries | Mononeuritis multiplex | |
| Mesenteric artery | Abdominal pain, gastrointestinal bleeding and perforation because of gut infarction | |
| Branches of coeliac artery | Infarction of liver, spleen, or pancreas | |
| Renal artery | Renal infarction | |
| Coronary arteries | Myocardial infarction or angina, coronary artery aneurysm, ischaemic cardiomyopathy | |
| Small pulmonary arteries | Necrotic lesions leading to cavitating lung shadows on chest radiograph | |
| Small arteries in ear, nose and throat region | Nasal crusting, epistaxis, sinusitis, deafness, stridor because of sub‐glottic stenosis | |
| Large vessel vasculitis (aorta and its branches) | Extracranial branches of carotid artery | Temporal headache (temporal artery), blindness (ophthalmic artery), jaw claudication (vessels supplying muscles of mastication) |
| Thoracic aorta and its branches | Limb claudication, absent pulses and unequal blood pressure, bruits, thoracic aortic aneurysms |
Classification of vasculitis on the basis of size of affected blood vessel
- Large vessel vasculitis
- Giant cell arteritis
- Takayasu’s arteritis
- Medium vessel vasculitis
- Polyarteritis nodosa
- Kawasaki’s disease
- Small vessel vasculitis
- ANCA associated vasculitis
- Wegener’s granulomatosis
- Churg‐Strauss syndrome
- microscopic polyangiitis
- Henoch‐Schonlein purpura
- Cutaneous leucocytoclastic angiitis
- Cryoglobulinaemic vasculitis
- General diagnostic approach
- ANCA associated vasculitis
There are five important questions to ask when faced with a patient with possible vasculitis (depending on clinical presentation):
- Is this a condition that could mimic the presentation of vasculitis?
- Is there a secondary underlying cause?
- Secondary causes of vasculitis
- Inflammatory diseases of unknown aetiology:
- rheumatoid vasculitis
- vasculitis associated with systemic lupus erythematosus and Sjogren’s syndrome
- inflammatory bowel disease
- sarcoidosis
- Infectious diseases:
- hepatitis B and C
- human immunodeficiency virus
- mycobacteria
- syphilis
- Neoplasia:
- haematological malignancies such as myeloproliferative and lymphoproliferative disorders
- solid tumours
- Drugs (almost any drug)
- Inflammatory diseases of unknown aetiology:
- Secondary causes of vasculitis
- What is the extent of vasculitis?
- How do I confirm the diagnosis of vasculitis?
- Important investigations to consider during initial evaluation of patients with suspected vasculitis
- To exclude vasculitis “mimics” and secondary causes
- Blood cultures
- Echocardiogram
- Hepatitis screen (B and C)
- HIV test
- Antiglomerular basement membrane antibody
- Antiphospholipid antibodies
- Antinuclear antibody
- To assess extent of vasculitis
- Urine dipstick and microscopy (all patients)
- Chest radiography (all patients)
- Nerve conduction studies/electromyography/CK
- To confirm diagnosis of vasculitis
- Biopsy and/or angiogram
- To identify the specific type of vasculitis
- ANCA
- c‐ANCA =
- Wegener’s granulomatosis (Very Strongly associated)
- Crescentic Glomerulonephritis (moderately associated)
- Polyarteritis Nodosa (Weakly associated)
- p‐ANCA =
- Crescentic Glomerulonephritis (Strongly associated)
- Polyarteritis Nodosa (Moderately associated)
- Churg-StraussVasculitis (Moderately associated)
- Granulomatosis with Polyangiitis (Weakly associated)
- Henoch-Schonlein Purpura (Possibly associated)
- Temporal Arteritis (Possibly associated)
- c‐ANCA =
- Cryoglobulin, Complement levels, Eosinophil counts/IgE levels
- Specific findings on biopsy (necrotising granulomatous inflammation, presence of IgA deposits, evidence of immune complex formation (or its absence))
- ANCA
- To exclude vasculitis “mimics” and secondary causes