Definition:
A condition characterized by a reaction that results in the inflammation of the blood vessels, hypersensitivity vasculitis happens when immune complexes lodge in the vessel wall, attracting polymorphonuclear leukocytes that in turn release tissue-degrading substances leading to an inflammatory process.
Diagnosis:
Henoch-Schonlein purpura is an important differential in diagnosing hypersensitivity vasculitis. Among the criteria are ages 16 above, use of possible triggering drugs, palpable painful purpura, maculopapular rash, and skin biopsy showing neutrophil infiltration.
Treatment:
Eliminating the cause of vasculitis is the most important part of the treatment. Some patients find taking antihistamines useful. Immunosuppressive agents are suggested if the vasculitis is damaging systems such as the kidneys.
Symptoms and Signs:
Normally painful and palpable petechiae or purpura is the common symptom of the condition. The purpura or skin vasculitis normally arise on crops, with common localizations on the forearms and legs. Lesions with black or brown centres usually result from necrosis of skin. The disorder sometimes affects nerves, the kidneys, joints and the heart. Also common is renal involvement.
Causes:
The disorder is usually due to a hypersensitivity reaction to a known drug, auto-antigens or infectious agents such as bacteria.
