Hypersensitivity vasculitis
| Hypersensitivity vasculitis | ||
| ICD-10 | M31.0 | |
|---|---|---|
| ICD-9 | 446.2 | |
| DiseasesDB | 7423 | |
| eMedicine | med/2930 | |
| MeSH | C14.907.940.910 | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Synonyms and keywords: 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:
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 over 16 years
- Use of possible triggering drug in relation to symptoms
- Palpable painful purpura (the three P's)
- Maculopapular rash
- Skin biopsy showing neutrophil infiltration around vessels
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
References
Template:Diseases of the musculoskeletal system and connective tissue