Arteritis

Arteritis is a vascular disorder characterized by inflammation of the walls of arteries,<ref>Template:DorlandsDict</ref> usually as a result of infection or autoimmune responses. Arteritis, a complex disorder, is still not entirely understood.<ref name="Hollier 1–8">Template:Cite journal</ref> Arteritis may be distinguished by its different types, based on the organ systems affected by the disease.<ref name="Hollier 1–8"/> A complication of arteritis is thrombosis, which can be fatal. Arteritis and phlebitis are forms of vasculitis.

Signs and Symptoms

Symptoms of general arteritis may include:<ref name="pmid7909656"/>

• Inflammation
• Fever
• Increased production of red blood cells (erythrocytes)
• Limping
• Reduced pulse

Diagnosis

Diagnosis of arteritis is based on unusual medical symptoms.<ref name="Wen 462–473">Template:Cite journal</ref> Similar symptoms may be caused by a number of other conditions, such as Ehlers-Danlos syndrome and Marfan syndrome (both heritable disorders of connective tissue), tuberculosis, syphilis, spondyloarthropathies, Cogans' syndrome, Buerger's, Behcet's, and Kawasaki disease.<ref name="Wen 462–473"/> Various imaging techniques may be used to diagnose and monitor disease progression. Imaging modalities may include direct angiography, magnetic resonance angiography, and ultrasonography.<ref name="Wen 462–473"/>

Angiography is commonly used in the diagnosis of Takayasu arteritis,<ref name="Wen 462–473"/> especially in the advanced stages of the disease, when arterial stenosis, occlusion, and aneurysms may be observed.<ref name="Wen 462–473"/> However, angiography is a relatively invasive investigation, exposing patients to large doses of radiation,<ref name="Wen 462–473"/> so is not recommended for routine, long-term monitoring of disease progression in patients with Takayasu arteritis.<ref name="Wen 462–473"/>

Computed tomography angiography can determine the size of the aorta and its surrounding branches, and can identify vessel wall lesions in middle to late stages of arteritis.<ref name="Wen 462–473"/> CTA can also show the blood flow within the blood vessels.<ref name="Wen 462–473"/> Like angiography, CTA exposes patients to high dosages of radiation.<ref name="Wen 462–473"/>

Magnetic resonance angiography is used to diagnose Takayasu arteritis in the early stages, showing changes such as the thickening of the vessel wall.<ref name="Wen 462–473"/> Even small changes may be measured, making MRA a useful tool for monitoring disease progression without exposing patients to the radiation of direct angiography or CTA.<ref name="Wen 462–473"/> MRA is an expensive investigation, and shows calcification of the aorta and distal branches less clearly than other imaging methods.<ref name="Wen 462–473"/>

Ultrasonography is an ideal method of diagnosing patients in early stages of arteritis when inflammation in the vessel walls occurs.<ref name="Wen 462–473"/> It can also show the blood flow within the blood vessels.<ref name="Wen 462–473"/> Ultrasonography is a popular first-line investigation for diagnosis because it is relatively quick, cheap, noninvasive, and does not expose patients to radiation.<ref name="Wen 462–473"/> It is also used for long-term monitoring of disease progression in Takayasu arteritis. Not all vascular lesions are visible on ultrasound, and the accuracy of the scan depends, to some extent, on the person reading the scan, as the results are observed in real time.<ref name="Wen 462–473"/>

Types

Arteritis may be primary or secondary to some other disease process. The primary types are:

Comparison of major types of arteritis
Arteritis	Affected organs	Histopathology
Takayasu arteritis	Large vessels,<ref name="pmid7909656">Template:Cite journal</ref> including aorta and arch branches<ref name=Fleshandbones>Stevens & Lowe: Pathology. At Fleshandbones.com</ref>	Histiocytes, giant cells<ref name=Fleshandbones/>
Giant cell arteritis, also often called temporal arteritis (although they differ slightly)	Superficial temporal artery, other medium- and large-sized vessels,<ref name=emedicine>eMedicine Specialties > Temporal Arteritis Author: Christopher H Lee, MD. Coauthor(s): Jean Marie Hammel, MD. Updated: Sep 8, 2009</ref> e.g. those supplying the head, eyes and optic nerves	Lymphocytes, macrophages, and multinucleated giant cells<ref name=emedicine/>
Polyarteritis nodosa	Medium-sized vessels, CNS, PNS damage, kidneys, gastrointestinal tract, skeletal muscle, heart<ref name=Fleshandbones/>	Neutrophils, fibrinoid necrosis<ref name=Fleshandbones/>

An example of a secondary arteritis is arteritis caused by infection with the fungal pathogen Candida albicans.<ref>Template:Cite journal</ref>

Giant cell arteritis

{{#invoke:Labelled list hatnote|labelledList|Main article|Main articles|Main page|Main pages}}

Giant cell arteritis contains two different types of arteritides that are almost indistinguishable from one another.<ref name="Hollier 1–8"/> It includes two types, temporal arteritis and Takayasu arteritis. Both types contain an occupancy of medium- and larger-sized arteries which are categorized based on the infiltration of the giant cells.<ref name="Hollier 1–8"/>

Takayasu arteritis

This type of arteritis is most common in females, with a median age of 25 years.<ref name="pmid7909656"/> Takayasu arteritis is more common in women of Asian descent who are in their reproductive years.<ref name="pmid7909656"/> However, over the past decades, its incidence in Africa, Europe, and North America has been increasing.<ref name="pmid7909656"/> Takayasu arteritis is an inflammatory disease that mainly affects the larger vessels such as the aorta and its surrounding branches.<ref name="pmid7909656"/> Research focused on Takayasu arteritis in the western parts of the world remains limited. An estimation suggests that, each year, the number of cases per million people is 2.6.<ref name="pmid7909656"/>

Temporal arteritis

Temporal arteritis, the second type of giant cell arteritis, is also a chronic, inflammatory disease involving mid- to large-sized arteries.<ref name="Chen 333–335">Template:Cite journal</ref> Temporal arteritis has a higher incidence in people of Scandinavian descent.<ref name="Chen 333–335"/> However, the incidence rate differs based on population, region and races.<ref name="Chen 333–335"/> Temporal arteritis is not uncommon in North America.<ref name="Chen 333–335"/> The incidence rate is around 0.017% for individuals over 50 years of age.<ref name="Chen 333–335"/>

Symptoms of temporal arteritis are classified as specific and nonspecific.<ref name="Chen 333–335"/>

Nonspecific symptoms:<ref name="Chen 333–335"/>

• Headache
• Low grade fever
• Sweating
• Anorexia (loss of appetite)
• Weight loss
• General malaise

Specific symptoms:<ref name="Chen 333–335"/>

• Claudication of the jaw
• Engorged, tender vessels

Specific symptoms usually develop in the advanced stages of temporal arteritis.<ref name="Chen 333–335"/> These symptoms can include damage to eyesight and sudden blindness in one or both eyes.<ref>Template:Cite journal</ref>

Polyarteritis nodosa of unknown mechanism can cause testicular pain. It is often associated with aneurysms and Hepatitis B.

Treatment

Medications

The first-line treatment for arteritis is oral glucocorticoid (steroid) medication, such as prednisone, taken daily for a period of three months.<ref name="pmid7909656"/> After this initial phase, the medication may be reduced in dose or frequency, e.g. every other day, if possible.<ref name="pmid7909656"/> If the disease worsens with the new treatment schedule, a cytotoxic medication may be given, in addition to the glucocorticoid.<ref name="pmid7909656"/> Commonly used cytotoxic agents include azathioprine, methotrexate, or cyclophosphamide.<ref name="pmid7909656"/> The dose of glucocorticoid medication may be decreased if response to treatment is good.<ref name="pmid7909656"/> This medication may be reduced gradually once the disease becomes inactive, slowly tapering the dose (to allow the body time to adjust) until the medication may be stopped completely.<ref name="pmid7909656"/> Conversely, if the disease remains active, the medication will need to be increased.<ref name="pmid7909656"/> After six months, if the medication cannot be reduced in frequency to alternate days, or if in 12 months the medications cannot be stopped completely, then treatment is deemed to have failed.<ref name="pmid7909656"/>

Pulsed therapy is an alternative method of administering the medications above, using much higher doses over a short period of time (a pulse), to reduce the inflammation within the arteries. Methylprednisolone, a glucocorticoid, is often used for pulse therapy; cyclophosphamide is an alternative. This method has been shown to be successful for some patients.<ref>Template:Cite journal</ref> Immunosuppressive pulse therapy, such as with cyclophosphamide, has also demonstrated relief of symptoms associated with arteritis.<ref>Template:Cite journal</ref>