Early manifestations include cold-induced Raynaud phenomenon (see later), instep foot pain induced by exercise (instep claudication), and superficial nodular phlebitis (venousinflammation).ThevascularinsufficiencyofBuerger disease tends to be accompanied by severe pain—even at rest—undoubtedly from the neural involvement. Chronic extremity ulcerations may develop, progressing over time (occasionally precipitously) to frank gangrene. Smoking abstinence in the early stages of the disease often ameliorates further attacks; however, once established, the vascular lesions do not respond to smoking abstinence.
Vasculitis resembling hypersensitivity angiitis or classic PAN may be seen in association with many other diseases, including malignancies and immunologic disorders such as rheumatoid arthritis, systemic lupus erythematosus, anti-phospholipid antibody syndrome, and Henoch-Schönlein purpura. Rheumatoid vasculitis may occur in patients with severe, long-standing rheumatoid arthritis; it can cause a clinically significant aortitis but more typically affects small-and medium-sized arteries, leading to visceral infarction. Linking vasculitis to specific disorders may have important therapeutic implications. For example, although classic immune complex lupus vasculitis and antiphospholipid antibody syndrome share certain morphologic features, the former requires anti-inflammatory therapy while anticoagulation is indicated in the latter.
Localized arteritis may be caused by the direct invasion of arteries by infectious agents, usually bacteria or fungi, and in particular Aspergillus and Mucor spp. Vascular invasion may be part of a nearby local tissue infection (e.g., bacterial pneumonia or an adjacent abscesses), or—less commonly— may arise from hematogenous spread of bacteria or embolization from infective endocarditis.
Vascular infections may weaken arterial walls and culminate in mycotic aneurysms described earlier, or may induce thrombosis and infarction. Thus, inflammation of vessels in bacterial meningitis can cause thrombosis and infarction, leading ultimately to extension of a subarachnoid infection into the brain parenchyma.
http://ebooksmedicine.net
Vasculitisisdefinedasinflammationofvesselwalls;itfrequentlyisassociatedwithsystemicmanifestations(includingfever,malaise,myalgias,andarthralgias)andorgandysfunctionthatdependsonthepatternofvascularinvolvement.
Vasculitiscanresultfrominfectionsbutmorecommonlyhasanimmunologicbasissuchasimmunecomplexdeposition,anti-neutrophilantibodies(ANCAs),oranti-ECantibodies.
Fig.10.22
Table10.4
Several disorders are characterized by inappropriate or exaggerated vasoconstriction of blood vessels.
Raynaud phenomenon results from vasoconstriction of arteries and arterioles in the extremities, particularly the fingers and toes, but also sometimes the nose, earlobes, or lips. The restricted blood flow induces paroxysmal pallor or cyanosis; involved digits characteristically show “red-white-andblue” color changes from most proximal to most distal, reflecting proximal vasodilation, central vasoconstriction, and more distal cyanosis, respectively. Raynaud phenomenon can be a primary entity or may be secondary to other disorders.
Primary Raynaud phenomenon (previously called Raynaud disease) is caused by exaggerated central and local vasomotor responses to cold or emotion; it affects 3% to 5% of the general population and has a predilection for young women. Structural changes in the arterial walls are absent except late in the course, when intimal thickening may appear. The course usually is benign, but in chronic cases, atrophy of the skin, subcutaneous tissues, and muscles may occur. Ulceration and ischemic gangrene are rare.