Vasculitis can be classified based on the size of the blood vessels affected:
Large Vessel Vasculitis:
- Examples:
- Giant Cell Arteritis (Temporal Arteritis): Affects large and medium-sized arteries, particularly the temporal arteries.
- Takayasu’s Arteritis: Affects the aorta and its main branches.
Medium Vessel Vasculitis:
- Examples:
- Polyarteritis Nodosa (PAN): Affects medium-sized arteries, typically involving kidneys, nerves, and muscles.
- Kawasaki Disease: Affects medium-sized arteries, particularly coronary arteries.
Small Vessel Vasculitis:
- Examples:
- Granulomatosis with Polyangiitis (GPA; Wegener’s): Affects small vessels in the respiratory tract and kidneys.
- Eosinophilic Granulomatosis with Polyangiitis (EGPA; Churg-Strauss): Affects small vessels and is often associated with asthma.
- Microscopic Polyangiitis: Affects small vessels in the lungs, kidneys, and skin.
Takayasu’s Arteritis
- Etiology: The exact cause is unknown, but it is believed to be an autoimmune disease. It is more common in young women and individuals of Asian descent. Genetic predisposition and environmental factors (such as infections) are thought to play a role.
- Clinical Features:
- Early stage: Often asymptomatic with nonspecific symptoms like fever, fatigue, weight loss, and muscle pain.
- Pulseless disease: Reduced or absent pulses in the upper extremities, commonly in the arms and neck.
- Vascular bruits: Heard over affected arteries.
- Symptoms related to ischemia: Can affect organs supplied by involved arteries, such as heart (angina, myocardial infarction), brain (TIA, stroke), kidneys (hypertension, renal failure), and extremities (claudication, cold sensitivity).
- Ocular involvement: Visual disturbances, diplopia, and blindness in severe cases.
- Management:
- Immunosuppressive therapy: Corticosteroids are the mainstay of treatment. High doses are often required initially, followed by tapering as inflammation decreases.
- Other immunosuppressive agents: Methotrexate, azathioprine, or cyclophosphamide may be used in severe cases.
- Disease monitoring: Regular imaging (angiography, MRI) to monitor disease progression and response to treatment.
- Management of complications: Address complications such as hypertension, renal dysfunction, and heart disease with appropriate medications.
Treatment aims to control inflammation, prevent complications, and preserve function in affected organs.