Cutaneous vasculitis refers to vasculitis affecting small- or medium-sized vessels in the skin and subcutaneous tissue but not the internal organs. Purpura, petechiae, or ulcers may develop. Diagnosis requires biopsy. Treatment depends on etiology and extent of disease.

Vasculitis can affect the small- or medium-sized vessels of the skin. Vasculitis affecting the small vessels of the skin (eg, arterioles, capillaries, postcapillary venules) tends to cause lesions such as purpura, petechiae, and possibly shallow ulcers. Livedo reticularis, nodules, and deep ulcers are usually caused by vasculitis of deeper, medium or large vessels. Any primary or secondary vasculitis can affect the skin, including that due to serum sickness, infections (eg, hepatitis C), cancers, rheumatologic or other autoimmune disorders, and hypersensitivity to drugs.

Terms used to describe cutaneous vasculitis can overlap and may be used inconsistently:

• Cutaneous vasculitis: This term describes vasculitis that affects the skin but not the internal organs.
• Cutaneous small-vessel vasculitis (CSVV): This term describes vasculitis that affects the small vessels of the skin but not the internal organs. CSVV sometimes refers to small-vessel vasculitis of unknown cause (also called idiopathic cutaneous small-vessel vasculitis).
• Leukocytoclastic vasculitis: This term describes a common type of CSVV, so-called because inflammation consists initially of neutrophils, which after degranulation result in deposition of nuclear debris (leukocytoclasis) in the vessel wall.
• Hypersensitivity vasculitis: This term previously used to mean CSVV but is now usually not used because the cause of CSVV is usually not hypersensitivity. However, hypersensitivity vasculitis is sometimes used to refer to CSVV caused by a known drug or infection.

Symptoms and Signs

Patients may present with skin symptoms such as lesions, including palpable purpura, petechiae, urticaria, ulcers, livedo reticularis, and nodules. If skin involvement is secondary to a systemic vasculitis, symptoms may also include fever, arthralgias, other organ involvement, or a combination.

Diagnosis

• Exclusion of clinically evident causes of systemic vasculitis
• Routine tests (eg, CBC, ESR, urinalysis, serum creatinine, chest x-ray)
• Biopsy
• Tests to identify the type and etiology of vasculitis (eg, cryoglobulins, antineutrophil cytoplasmic antibodies [ANCA], hepatitis B and C antibodies, complement levels, rheumatoid factor, blood cultures, protein electrophoresis)

A diagnosis of vasculitis limited to the skin requires a complete history and physical examination. History is focused at identifying causes, such as new drugs or infections. Evaluation is also focused on excluding manifestations of inflammation or vasculitis in other organs, such as

• Lungs: Shortness of breath, cough, hemoptysis, and signs of consolidation
• Kidneys: New-onset hypertension or edema
• Nerves: New-onset asymmetric weakness or paresthesias
• Intestine: New-onset abdominal pain, diarrhea, and bloody stools

Urinalysis should exclude blood, protein, and RBC casts. A chest x-ray is needed to check for infiltrates (suggesting alveolar hemorrhage). CBC and other blood tests are needed to check for anemia, to determine platelet count and serum creatinine level, and to check for elevated levels of acute-phase reactants (eg, ESR, C-reactive protein).

Skin biopsy should be done, optimally within 24 to 48 h after vasculitic lesions appear. Diagnostic yield depends on the depth of the biopsy. Generally, deep punch biopsy or excision biopsy into the subcutis is preferred; these biopsies can sample small- and medium-sized vessels. Shave biopsy is usually inadequate.

If histologic examination detects the following, cutaneous vasculitis is confirmed:

• Infiltration of the vessel wall by inflammatory cells, resulting in disruption and destruction of the vessel wall
• Intramural and intraluminal fibrin deposition (fibrinoid necrosis)
• Extravasation of RBCs
• Nuclear debris (leukocytoclasis)

Direct immunofluorescence staining is needed to check for IgA, IgM, and IgG and complement deposition in and around the vessel wall, which suggests an immune complex–mediated process, a lymphoproliferative disorder, or other neoplastic disorder, especially in adults. Direct immunofluorescence staining may help diagnose cryoglobulinemic vasculitis, RA, immunoglobulin A–associated vasculitis, or leukocytoclastic vasculitis. Tests done to identify the cause of vasculitis include cryoglobulins, antineutrophil cytoplasmic antibodies [ANCA], hepatitis B and C antibodies, complement levels, rheumatoid factor, blood cultures, and serum and urine protein electrophoresis. Other tests are done as needed to identify clinically suspected causes of vasculitis.

Treatment

• Treatment of the cause
• Drugs, beginning with antihistamines and progressing to colchicine, hydroxychloroquine or dapsone, or a short course of low-dose corticosteroids as needed

Treatment is first directed at any identified cause. If no cause is identified and vasculitis is limited to the skin, treatment is minimal and conservative. Support hose and antihistamines may be sufficient. If this treatment is ineffective, colchicine, hydroxychloroquine or dapsone, or a short course of low-dose corticosteroids can be tried.

Rarely, stronger immunosuppressants (eg, azathioprine, methotrexate) are used, particularly if lesions ulcerate or if corticosteroids must be taken indefinitely to control symptoms.

Key Points

• Cutaneous vasculitis affects small- and medium-sized vessels and can be primary or secondary.
• Manifestations can include palpable purpura, petechiae, urticaria, ulcers, livedo reticularis, and nodules.
• Exclude other causes of vasculitis.
• Do routine laboratory tests and biopsy.
• Treat the cause when possible.

Last full review/revision April 2013 by Carmen E. Gota, MD