Vasculitis - Small Vessels

Vasculitides are characterized by blood vessel inflammation with possible necrosis, ischemia, and organ damage. The vessels and organs affected vary by the specific vasculitic disorder – the ones we'll address in this tutorial affect the small arteries, veins, and capillaries. General symptoms are due to systemic inflammation, and include fever, arthritis, arthralgia, fatigue, and weight loss. Cutaneous manifestations can occur in isolation. Treatments include corticosteroids and immunosuppressants. Granulomatosis with polyangiitis Note that this was formerly called Wegener's granulomatosis, but this nomenclature is being phased out due to Wegener's associations with the Nazi party. Characterized by necrotic granulomatous inflammation; granulomas comprise giant cells, plasma cells, lymphocytes, neutrophils, and eosinophils. The respiratory tract is typically involved, which can lead to sinusitis, otitis media, rhinorrhea, and epistaxis; the mucosa can become granular and crusted. – Erosion and destruction of the nasal septum can case the nasal bridge to collapse. – Destruction of the tracheobronchial tree can lead to stenosis and airway obstruction. – When the lungs are involved, patients can develop a cough, difficulty breathing, hemoptysis, and hemorrhaging. The kidneys are also commonly affected, leading to necrotizing crescent focal glomerulonephritis and thrombosis. Cutaneous manifestations vary, and include palpable purpura, livedo reticularis, ulcers, and the formation of deep, tender nodules. The eyes, nervous system, heart, and musculoskeletal system can also be involved. Granulomatosis with polyangiitis most commonly occurs in Caucasians; the average age of onset is 40 years. Eosinophilic granulomatosis with polyangiitis Aka, Churg-Strauss ANCA-associated disorder characterized by necrotizing granulomatous inflammation. Manifests as both vascular and extravascular necrotizing granulomas with eosinophil blood and tissue infiltrations. Three stages of eosinophilc granulomatosis with polyangiitis: The allergic stage is often marked by adult-onset asthma, which can develop years before full presentation of the disorder. Patients may also develop sinusitis, hemoptysis, and pulmonary infiltrates as part of the allergic stage. The eosinophilic stage is characterized by blood and tissue infiltration of eosinophils. The vasculitic stage can affect multiple organ systems: – Nervous system involvement is associated with multiple mononeuropathy. – Cutaneous involvement manifests as nodules or papules on the extensor surfaces, especially around the elbows. – GI involvement can produce pain, diarrhea, and bleeding. – Cardiac involvement often leads to inflammation and/or cardiomyopathies. Be aware that the kidneys are less commonly affected than in the other ANCA-associated vasculitides. Disease onset is usually during the late 40s. Microscopic polyangiitis Characterized by necrotizing pauci-immune inflammation without granulomas. Renal involvement is associated with glomerulonephritis and rapid progression to renal failure. Purpuric rash is common. The lungs are less commonly affected, but, when they are, alveolar hemorrhage and fibrosis can be serious. Microscopic polyangiitis usually develops in patients 50-60 years old. Immunoglobulin A-associated vasculitis Aka, Henoch-Schonlein purpura Occurs when IgA immune complexes are deposited in the small vessels. Patients develop palpable purpura, especially on the lower extremities, arthralgias, abdominal pain, dark stools, and focal glomerulonephritis. It's common and self-limited in children; in adults, it often becomes chronic. Cryoglobulinemia Occurs when cryoglobulins in the blood clump at cold temperatures. Patients experience notable fatigue, palpable purpura in the legs, arthralgias in the knees and hands, glomerulonephritis, and PNS disturbances. Type I cryoglobulinemia is associated with B-cell lymphoproliferative disorder. Types II and III (aka, mixed cryoglobulinemia) is assoc. with Hepatitis C virus. Autoimmune Disorders The autoimmune disorders systemic lupus erythematosus and rheumatoid arthritis are also associated with small-vessel vasculitis.