Vasculitis — Causes, Symptoms, Diagnosis & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Vasculitis is a group of disorders characterized by inflammation of blood vessel walls (arteries, veins, or capillaries), leading to vessel wall thickening, narrowing, occlusion, or aneurysm formation. This disrupts blood flow and causes ischemic damage to tissues and organs supplied by the affected vessels. Vasculitis is classified by the size of vessels predominantly affected: large-vessel (giant cell arteritis, Takayasu arteritis), medium-vessel (polyarteritis nodosa, Kawasaki disease), and small-vessel (ANCA-associated vasculitides including granulomatosis with polyangiitis/GPA, microscopic polyangiitis/MPA, eosinophilic granulomatosis with polyangiitis/EGPA; immune complex vasculitides including IgA vasculitis and cryoglobulinemic vasculitis). Although individually rare, vasculitis can cause life-threatening organ failure if untreated and requires specialist rheumatological management. The clinical heterogeneity of vasculitis — ranging from self-limiting cutaneous disease to rapidly progressive organ-threatening disease causing renal failure and blindness — makes it one of the most diagnostically challenging conditions in rheumatology and demands specialist multidisciplinary assessment without delay.

Most vasculitides are autoimmune — the immune system attacks vessel walls, though the exact trigger is often unknown. ANCA-associated vasculitis (AAV) involves antineutrophil cytoplasmic antibodies (PR3-ANCA in GPA; MPO-ANCA in MPA) activating neutrophils to damage small vessel walls. Drug-induced vasculitis can be triggered by propylthiouracil, hydralazine, minocycline, cocaine contaminated with levamisole, and biologic agents. Infection-associated vasculitis: hepatitis B (polyarteritis nodosa), hepatitis C (cryoglobulinemic vasculitis), HIV. Giant cell arteritis (GCA) affects only individuals over 50 years of age and is strongly associated with HLA-DRB1 alleles and polymyalgia rheumatica (present in 50% of GCA cases). IgA vasculitis (Henoch-Schonlein purpura) is the most common vasculitis in children, often triggered by preceding upper respiratory infection.

Symptoms depend on the vessel size affected and organ involved. Constitutional symptoms common to most vasculitides: fever, fatigue, weight loss, night sweats, and malaise — often the initial presentation. Granulomatosis with polyangiitis (GPA): chronic sinusitis and nasal crusting, epistaxis, saddle-nose deformity, hemoptysis (pulmonary hemorrhage), and rapidly progressive glomerulonephritis causing hematuria and renal failure. Giant cell arteritis: severe temporal headache, scalp tenderness, jaw claudication (pain when chewing), visual loss or diplopia (ophthalmic emergency), and elevated inflammatory markers (ESR often above 100 mm/hr). Polyarteritis nodosa: skin livedo reticularis, peripheral neuropathy (mononeuritis multiplex), abdominal angina, hypertension, and orchitis. IgA vasculitis: palpable purpuric rash on lower limbs and buttocks, arthralgia, abdominal pain, and haematuria in children.

Diagnosis requires clinical assessment, laboratory testing, imaging, and often tissue biopsy to confirm vasculitic inflammation. Blood tests: ANCA (PR3/MPO specificity distinguishes GPA from MPA); anti-GBM antibodies (Goodpasture's); complement levels (C3/C4 — low in lupus, cryoglobulinemia); hepatitis B/C serology; cryoglobulins; ESR and CRP (markedly elevated in GCA, PAN); renal function, urinalysis, and urine protein:creatinine ratio (renal involvement). Imaging: CT chest/sinuses (upper and lower airway involvement in GPA); CT/MRI angiography for large vessel vasculitis; PET-CT for GCA/Takayasu. Tissue biopsy remains the gold standard: temporal artery biopsy for GCA; renal biopsy for pauci-immune crescentic GN in AAV; skin biopsy for cutaneous vasculitis with IgA immunofluorescence. Nerve conduction studies for mononeuritis multiplex.

Treatment depends on vasculitis type, severity, and organ involvement. Induction therapy for severe ANCA-associated vasculitis: high-dose prednisolone (1 mg/kg/day, tapering) combined with either cyclophosphamide (CYCLOPS regimen — monthly IV pulses) or rituximab (anti-CD20 biologic — preferred in relapsing disease or cyclophosphamide toxicity concern). Avacopan (complement C5a receptor antagonist) enables steroid-sparing in AAV. Maintenance therapy: rituximab 500 mg every 6 months or azathioprine/methotrexate for 18-24 months after remission. Giant cell arteritis: high-dose prednisolone 40-60 mg/day immediately (do not delay awaiting biopsy if visual symptoms present); tocilizumab (IL-6 inhibitor) enables steroid tapering and reduces relapse. Kawasaki disease: aspirin and IVIG within 10 days. IgA vasculitis: most self-limiting; corticosteroids for severe abdominal or renal involvement. Treatment intensity must be carefully matched to organ involvement severity; over-treatment causes significant immunosuppression-related harm including infection and malignancy, while under-treatment risks irreversible organ damage and death.

Untreated vasculitis can be rapidly fatal or cause irreversible organ damage. Giant cell arteritis without immediate high-dose corticosteroids causes permanent visual loss in 15-20% of untreated patients — ischaemic optic neuropathy from posterior ciliary artery occlusion produces sudden, often bilateral blindness that is irreversible even with subsequent treatment. ANCA-associated vasculitis (GPA, MPA) untreated progresses to dialysis-dependent renal failure within weeks to months from rapidly progressive crescentic glomerulonephritis; pulmonary haemorrhage from capillaritis causes massive haemoptysis and acute respiratory failure with mortality of 25-50% without immediate immunosuppression. Granulomatosis with polyangiitis causes saddle-nose deformity from septal perforation and subglottic stenosis requiring tracheal dilatation. Takayasu arteritis causes subclavian stenosis with arm claudication, hypertension from renal artery stenosis, aortic aneurysm formation, and stroke from carotid stenosis. Polyarteritis nodosa causes mesenteric artery ischaemia and bowel infarction — a surgical emergency — and renal artery microaneurysms with spontaneous rupture. IgA vasculitis (HSP) nephritis progresses to chronic kidney disease in approximately 2-5% of adult cases if untreated. Long-term immunosuppressive treatment itself causes significant complications: cyclophosphamide causes haemorrhagic cystitis (cumulative bladder toxicity), infertility, and secondary malignancy; high-dose corticosteroids cause osteoporosis, diabetes, cataracts, and adrenal suppression.

There is no established prevention for most vasculitides as they are autoimmune in nature. Hepatitis B vaccination prevents HBV-associated polyarteritis nodosa. For drug-induced vasculitis, cessation of the causative drug leads to resolution. Long-term immunosuppression requires monitoring: regular blood counts (cyclophosphamide-induced myelosuppression), renal function, bone density (corticosteroid-induced osteoporosis — prescribe calcium, vitamin D, and bisphosphonate), blood pressure, and urine for haematuria (bladder toxicity with cyclophosphamide). Pneumocystis pneumonia prophylaxis (co-trimoxazole) during active immunosuppression. Regular ESR/CRP and ANCA monitoring detects relapse. Patients with GCA require regular ophthalmological monitoring. Pneumococcal and influenza vaccination is recommended in all immunosuppressed vasculitis patients.

Vasculitis is a potential medical emergency — seek urgent care if you experience sudden visual loss or double vision (GCA emergency — delay risks permanent blindness), large-volume hemoptysis (pulmonary hemorrhage in AAV), rapidly declining kidney function or blood in urine, severe headache with scalp tenderness in someone over 50, or neurological symptoms such as foot or wrist drop (mononeuritis multiplex). Any new unexplained purpuric rash (non-blanching spots), fever with joint pain and weight loss, or persistently elevated inflammatory markers should prompt early rheumatological referral. Do not wait for a diagnosis — start urgent investigation in the same week. All patients with suspected vasculitis should be referred urgently to a specialist rheumatologist, nephrologist, or ophthalmologist depending on the predominant organ system involved, as early diagnosis and prompt treatment significantly reduces long-term irreversible organ damage and mortality.