View source for Hypersensitivity vasculitis

{{Infobox_Disease |
  Name           = {{PAGENAME}} |
  Image          = |
  Caption        = |
  DiseasesDB     = 7423 |
  ICD10          = {{ICD10|M|31|0|m|30}} |
  ICD9           = {{ICD9|446.2}} |
  ICDO           = |
  OMIM           = |
  MedlinePlus    = |
  eMedicineSubj  = med |
  eMedicineTopic = 2930 |
  MeshName       = Hypersensitivity+Vasculitis |
  MeshNumber     = C14.907.940.910 |
}}
{{SI}}
{{CMG}}; '''Associate Editor-In-Chief:''' {{CZ}}

{{SK}} Hypersensitivity angiitis, leukocytoclastic vasculitis

==Overview==
Hypersensitivity vasculitis is inflammation of the vessel wall which is usually due to a [[hypersensitivity reaction]] to a known drug, auto-antigens or infectious agents such as bacteria.

==Pathophysiology==
[[Immune complexes]] lodge in the vessel wall, attracting [[polymorphonuclear leukocytes]] who in turn release tissue-degrading substances leading to an inflammatory process.  This disorder may affect the skin only, but sometimes affect nerves, the kidneys, joints and the heart. Renal involvement is common.

== Diagnosis ==

==History==
A detailed history should be obtained regarding medications and potential exposure to infectious agents.

===Physical Examination===
====Skin====
*Palpable, normally painful, [[petechiae]] or [[purpura]] (skin vasculitis).
*The lesions normally arise in crops, with common localizations being the forearms and legs.
*[[Necrosis]] of skin tissue can yield lesions with black or brown centres.

===Laboratory Studies===
The following studies are routinely obtained:
*[[Hepatitis serologies]]
*[[Antinuclear antibodies]]
*[[Rheumatoid factor]]
*[[Cryoglobulins]]

===Skin Biopsy===
Skin biopsy of the lesions reveal inflammation of the small vessels, termed leukocytoclastic vasculitis, which is most prominent in postcapillary venules.

== Diagnostic Criteria ==
At least '''3 out of 5 criteria''' yields a sensitivity of 71% and a specificity of 84%:

* Age >16.
* Use of possible triggering drug in relation to symptoms.
* Palpable painful purpura (the three P's).
* Maculopapular rash.
* Skin biopsy showing neutrophil infiltration around vessel.

==Treatment==

The most important part of the treatment is to eliminate the cause of the vasculitis, if at all possible. Antihistamines prove helpful to some patients. If the vasculitis is damaging organ systems such as the kidneys, immunosuppressive agents are indicated.

==See also==
* [[Vasculitis]]
* [[Goodpasture's syndrome]]
* [[Henoch-Schönlein purpura]]


==References==
{{Reflist|2}}

{{Diseases of the musculoskeletal system and connective tissue}}


[[Category:Dermatology]]
[[Category:Inflammations]]

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