Vasculitis

The term vasculitis literally means inflammation of the walls of blood vessels. Vasculitides include a spectrum of diseases with variable causative factors and features which are classified on the basis of site and type of blood vessels involved. However, there is no standard classification of vasculitis because the causes and process of disease development are only superficially understood and the clinical presentations tend to overlap. It may occur in association with other systemic diseases or it may occur as a primary disease process, in which case, it is termed primary systemic vasculitides. Secondary vasculitis may occur as a complication of other systemic autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis.

The common complaints of patients who report early in the clinics include fever, muscle and joint pains, malaise, and night sweats. Common investigations will reveal a rise in erythrocyte sedimentation rate, C-reactive protein, and plasma viscosity on examination of a blood specimen in active disease.

The human vascular system is endowed with a multitude of blood vessels, responsible for providing oxygen and nutrients to the deepest and farthest cells. Integrity of the vascular system keeps the body alive and warm. These vessels, namely the arteries (red), veins (blue), and capillaries, vary in size from an inch in diameter (aorta) to smaller, thinner vessels, barely visible to the human eye. Thence, the vasculitides are divided on the basis of size of vessels into large, medium, and small vessel vasculitis.

Large vessel vasculitis has two types: giant cell arteritis and Takayasu's arteritis. Giant cell or temporal arteritis usually victimizes patients older than 50 years. It is the most common type of primary systemic vasculitis affecting 200 per 1,000,000 population per year. It presents itself with throbbing headache of one side, facial pain, and claudicating of jaw when eating. It may affect the aorta, the largest vessel emerging from the heart, and its major branches, often it affects the temporal artery supplying the side of head. The inflammation is chronic and is characterized by the presence of giant cells and granulomas (any small aggregation of mononuclear inflammatory cells) in tissue sections, attributing the disease its name. Later in its course, the inflammation can be so intense that it may lead to loss of vision, usually sudden and painless, affecting part or the entire visual field. Double vision may also occur.

The therapeutic strategy is that of high-dose corticosteroids (antiinflammatory agents) until the disease goes into remission. The patient is kept on a low-maintenance dose for two years to avoid relapse and visual loss. Biopsy is the confirmatory test. The disease is monitored by analyzing serum CRP, ESR, and plasma viscosity.

Takayasu's arteritis is also an inflammation (fibrous thickening) of the aorta and its main branches, but it occurs in younger patients below 50 years of age. It is most common in Asia and the Far East, affecting primarily women younger than 40. It is characterized by involvement of eyes and weakening of pulses in arms (pulseless disease).

If the disease affects the vascular supply to the arms, head, neck, and heart, it is called aortic arch syndrome and it presents as claudication of the arms, loss of arm pulses, variation in blood pressure if recorded from both arms of more than 10 mm Hg, arterial bruits, angina, back flow of blood into the left ventricle of the heart, dizziness and syncope (temporary loss of consciousness), stroke, and visual disturbances. If the disease affects the descending branches of aorta, it is termed descending aortic syndrome, affecting the intestines, urinary system, and hypertension secondary to renal ischemia. ESR and CRP are markers but magnetic resonance imaging (MRI) and angiography are diagnostic tests. Treatment is with steroids or other cytotoxic adjuvant drugs such as cyclophosphamide.

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