Hypersensitivity vasculitis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [2] Luke Rusowicz-Orazem, B.S.

Synonyms and keywords: Hypersensitivity angiitis, leukocytoclastic vasculitis, LCV, leucocytoclastic venulitis, small-vessel vasculitis, cutaneous leukocytoclastic angiitis

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.

Causes

Causes by Organ System

Cardiovascular	Vasculitis
Chemical/Poisoning	No underlying causes
Dental	No underlying causes
Dermatologic	Erythema elevatum diutinum, Granuloma faciale, Henoch-schönlein purpura
Drug Side Effect	Allopurinol, Amoxicillin, Azficel-t, Coumarin, Letrozole, Nsaids, Orlistat, Penicillin, Phenytoin, Sulfonamide, Thiazide diuretics, Thiouracil, Warfarin
Ear Nose Throat	Sjögren’s syndrome
Endocrine	No underlying causes
Environmental	No underlying causes
Gastroenterologic	Inflammatory bowel disease
Genetic	No underlying causes
Hematologic	Acute infantile hemorrhagic edema, Cryoglobulinemia, Erythema elevatum diutinum, Henoch-schönlein purpura
Iatrogenic	No underlying causes
Infectious Disease	Hepatitis b, Hepatitis c
Musculoskeletal/Orthopedic	No underlying causes
Neurologic	No underlying causes
Nutritional/Metabolic	No underlying causes
Obstetric/Gynecologic	No underlying causes
Oncologic	Cancer, Granuloma faciale
Ophthalmologic	No underlying causes
Overdose/Toxicity	No underlying causes
Psychiatric	No underlying causes
Pulmonary	No underlying causes
Renal/Electrolyte	No underlying causes
Rheumatology/Immunology/Allergy	Rheumatoid arthritis, Serum sickness, Sjögren’s syndrome, Systemic lupus erythematosus
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Miscellaneous	No underlying causes

Causes in Alphabetical Order

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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.

References

Template:Diseases of the musculoskeletal system and connective tissue

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