Vasculitis

The clinical presentation of the various vasculitides on the skin and internal organs is mostly determined by the diameter or size of the vessels mainly affected. Non-specific symptoms are common and include fever, headache, fatigue, myalgia, weight loss, and arthralgia. All forms of vasculitides, even large vessel vasculitides, may cause skin manifestations. The most common skin manifestations include purpura, nodules, livedo reticularis, skin ulcers, and purpuric urticaria. == Causes ==

There are several different etiologies for vasculitides. Although infections usually involve vessels as a component of more extensive tissue damage, they can also directly or indirectly cause vasculitic syndromes through immune-mediated secondary events. Simple vascular thrombosis usually only affects the luminal process, but through the process of thrombus organization, it can also occasionally cause a more chronic vasculitic syndrome. The autoimmune etiologies, a particular family of diseases characterized by dysregulated immune responses that produce particular pathophysiologic signs and symptoms, are more prevalent. == Classification ==

Primary systemic, secondary, and single-organ vasculitides are distinguished using the highest classification level in the 2012 Chapel Hill Consensus Conference nomenclature. Primary systemic vasculitis Primary systemic vasculitis is categorized by the size of the vessels mainly involved. Primary systemic vasculitis includes large-vessel vasculitis, medium-vessel vasculitides, small-vessel vasculitides, and variable-vessel vasculitides. Medium vessel vasculitis Medium vessel vasculitis (MVV) is a type of vasculitis that mostly affects the medium arteries, which are the major arteries that supply the viscera and their branches. Any size artery could be impacted, though. Vasculitis frequently coexists with infections, and several infections, including hepatitis B and C, HIV, infective endocarditis, and tuberculosis, are significant secondary causes of vasculitis. Except for rheumatoid vasculitis, the majority of secondary vasculitis forms are exceedingly rare. Single-organ vasculitis Single-organ vasculitis, formerly known as "localized", "limited", "isolated", or "nonsystemic" vasculitis, refers to vasculitis that is limited to one organ or organ system. Examples of this type of vasculitis include gastrointestinal, cutaneous, and peripheral nerve vasculitides. == Diagnosis ==

showing a vasculitis (eosinophilic granulomatosis with polyangiitis). H&E stain. • 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 organ involvement. A brain SPECT can show decreased blood flow to the brain and brain damage. • The definite diagnosis of vasculitis is established after a biopsy of involved organ or tissue, such as skin, sinuses, lung, nerve, brain, and kidney. The biopsy elucidates the pattern of blood vessel inflammation. :*Some types of vasculitides display leukocytoclasis, which is vascular damage caused by nuclear debris from infiltrating neutrophils. It typically presents as palpable purpura. The combined evaluation of the intensity and the extension of FDG vessel uptake at diagnosis can predict the clinical course of the disease, separating patients with favourable or complicated progress. • Acute onset of vasculitis-like symptoms in small children or babies may instead be the life-threatening purpura fulminans, usually associated with severe infection. In this table: ANA = antinuclear antibodies, CRP = C-reactive protein, ESR = erythrocyte sedimentation rate, dsDNA = double-stranded DNA, ENA = extractable nuclear antigens, RNP = ribonucleoproteins; VDRL = Venereal Disease Research Laboratory == Treatment ==

Treatments are generally directed toward stopping the inflammation and suppressing the immune system. Typically, corticosteroids such as prednisone are used. Additionally, other immune suppression medications, such as cyclophosphamide, 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. == See also ==