Cutaneous small-vessel vasculitis

Skin lesions Initially red to pink, flat spots (formally, "macules") and raised bumps (formally, "papules") may be seen on the skin. This appears as deep red to purple spots that feel raised to the touch. Purpura refers to the red-purple discolored spots, while palpable implies that these spots can be felt as raised from the surrounding skin. Additionally, when gently pressed, the color does not fade to a lighter color ("non-blanching"). The red-purple color of the lesions is due to the inflammation in the blood vessels, causing red blood cells to escape into the dermis skin layer. With treatment, the lesions typically resolve in weeks to months and leave behind flat spots that are darker than the surrounding skin (see "Postinflammatory hyperpigmentation" on "Hyperpigmentation"). A portion of cases may be persistent or recurrent. This tends to occur when the vasculitis is associated with chronic conditions such as connective tissue diseases. Associated symptoms In most cases, skin lesions do not cause symptoms; however, itching, burning, or pain may occur. Frequently reported symptoms include mild fever, muscle pain, joint pain, or an overall feeling of discomfort. Additional symptoms depend on the cause of the vasculitis and if other organ systems are involved. For example, if the vasculitis is a manifestation of Henoch–Schönlein purpura, individuals may also experience abdominal pain or blood in the urine. ==Cause==

Cutaneous vasculitis can have various causes, including but not limited to medications, bacterial and viral infections, or allergens. It is estimated that 45–55% of cases are idiopathic, meaning the cause is unknown. In cases where a cause can be determined, medications and infectious pathogens are most common in adults, while IgA vasculitis (Henoch–Schönlein purpura) frequently affects children. Other etiologies include autoimmune conditions and malignancies, usually hematologic (related to the blood). Once activated, neutrophils then release preformed substances, including enzymes, causing damage to vessel tissue. The immune system senses these altered proteins as foreign and produces antibodies in efforts to eliminate them from the body. A similar process occurs with infectious agents, such as bacteria, in which antibodies target microbial components. ==Diagnosis==

The diagnostic testing for vasculitis should be guided by the patient's history and physical exam. The clinician should ask about the duration, onset, and presence of any associated symptoms such as weight loss or fatigue (that would indicate a systemic cause). Skin biopsy (punch or excisional) is the most definitive diagnostic test and should be performed with 48 hours of appearance of the vasculitis. Classification Subtypes of small-vessel vasculitis include: :* Acute hemorrhagic edema of infancy :* Urticarial vasculitis :* Cryoglobulinemic vasculitis :* Erythema elevatum diutinum :* Granuloma faciale :* ANCA-associated vasculitis :* Arthropod bites :* Platelet dysfunction or deficiency :* Cholesterol emboli :* Septic emboli :* Livedoid vasculopathy ==Treatment==

Treatment should be directed towards the specific underlying cause of the vasculitis. If no underlying cause is found and the vasculitis is truly limited to the skin, then treatment is primarily supportive. Oral colchicine or dapsone are often used for this purpose. If rapid control of symptoms is needed, a short course of high-dose oral steroids may be given. Immunosuppressive agents such as methotrexate and azathioprine may be used in truly refractory cases not responsive to colchicine or dapsone. ==Additional images==

Image:LV1,2010.JPG| Image:LV22010.JPG| Image:Leukocytoclastic vasculitis caused by reaction to minocycline.jpg| Image:LV4.JPG == See also ==