Vasculitis

Vasculitis (plural: vasculitides)^[1] refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels.^[2] Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis.^[3] Vasculitis is primarily due to leukocyte migration and resultant damage.

Although both occur in vasculitis, inflammation of veins (phlebitis) or arteries (arteritis) on their own are separate entities.

Classification

There are many ways to classify vasculitis.

• It can be classified by the underlying cause. For example, the cause of syphilitic aortitis is infectious (aortitis simply refers to arteritis of the aorta, which is an artery.) However, the cause of many forms of vasculitis are poorly understood. There is usually an immune component, but the trigger is often not identified. In these cases, the antibody found is sometimes used in classification, as in ANCA-associated vasculitides.
• It can be classified by the location of the affected vessels. For example, ICD-10 classifies "vasculitis limited to skin" with skin conditions (under "L"), and "necrotizing vasculopathies" with musculoskeletal system and connective tissue conditions (under "M"). Arteritis/phlebitis on their own are classified with circulatory conditions (under "I").
• Vasculitides can be classified by the type or size of the blood vessels that they predominantly affect.^[4] Apart from the arteritis/phlebitis distinction mentioned above, vasculitis is often classified by the caliber of the vessel affected. However, there can be some variation in the size of the vessels affected.

Conditions

Some disorders have vasculitis as their main feature. The major types are given in the table below:

Takayasu's arteritis, polyarteritis nodosa and giant cell arteritis are sometimes classified as vasculitis as well, but rather belong to arteritis since they mainly involve arteries.

Furthermore, there are many conditions that have vasculitis as an accompanying or atypical symptom, including:

• Rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and dermatomyositis
• Cancer, such as lymphomas
• Infections, such as hepatitis C
• Exposure to chemicals and drugs, such as amphetamines, cocaine, and anthrax vaccines which contain the Anthrax Protective Antigen as the primary ingredient.

Symptoms

Possible symptoms include:^[6]

• General symptoms: Fever, weight loss
• Skin: Palpable purpura, livedo reticularis
• Muscles and joints: Myalgia or myositis, arthralgia or arthritis
• Nervous system: Mononeuritis multiplex, headache, stroke, tinnitus, reduced visual acuity, acute visual loss
• Heart and arteries: Myocardial infarction, hypertension, gangrene
• Respiratory tract: Nose bleeds, bloody cough, lung infiltrates
• GI tract: Abdominal pain, bloody stool, perforations
• Kidneys: Glomerulonephritis

Diagnosis

• Laboratory tests of blood or body fluids are performed for patients with active vasculitis. Their results will generally show signs of inflammation in the body, such as increased erythrocyte sedimentation rate (ESR), elevated C-reactive protein (CRP), anemia, increased white blood cell count and eosinophilia. Other possible findings are elevated antineutrophil cytoplasmic antibody (ANCA) levels and hematuria.
• Other organ functional tests may be abnormal. Specific abnormalities depend on the degree of various organs involvement.
• The definite diagnosis of vasculitis is established after a biopsy of involved organ or tissue, such as skin, sinuses, lung, nerve, and kidney. The biopsy elucidates the pattern of blood vessel inflammation.
• An alternative to biopsy can be an angiogram (x-ray test of the blood vessels). It can demonstrate characteristic patterns of inflammation in affected blood vessels.

Treatment

Treatments are generally directed toward stopping the inflammation and suppressing the immune system. Typically, cortisone-related medications, such as prednisone, are used. Additionally, other immune suppression drugs, such as cyclophosphamide and others, are considered. In case of an infection, antimicrobial agents including cephalexin may be prescribed. Affected organs (such as the heart or lungs) may require specific medical treatment intended to improve their function during the active phase of the disease.

References