Urticarial vasculitis

What is urticarial vasculitis?

Urticarial vasculitis is a variant of cutaneous vasculitis. It is characterised by inflamed and reddened patches or weals on the skin that appear to resemble urticaria, but when the skin is examined closely under a microscope, vasculitis is found (inflamed blood vessels).

Urticarial vasculitis is generally classified as two types, normocomplementaemic and hypocomplementaemic (normal or lowered levels of complement proteins found on blood testing). Although both types may be associated with systemic symptoms such as angioedema, abdominal or chest pain, fever, and joint pain, this is more apparent in the hypocomplementaemic form. This form has also been linked to the connective tissue disease systemic lupus erythematosus (SLE).

What causes urticarial vasculitis?

The cause of urticarial vasculitis is unknown but it has been associated with the following conditions:

• Inflammatory connective disorders such as SLE and Sjögren syndrome.
• Immunoglobulin disorders such as immunoglobulin A and immunoglobulin M monoclonal gammopathies
• Leukaemia and internal cancers
• Viral diseases such as hepatitis B, hepatitis C and infectious mononucleosis (glandular fever)
• Drug-induced conditions from ACE inhibitors, penicillin, sulfonamides, fluoxetine and thiazides.

However, the majority of cases of urticarial vasculitis are idiopathic (arise from no known cause).

What are the features of urticarial vasculitis?

The first symptom of urticarial vasculitis is an urticarial eruption that is often painful or has a burning sensation. In some cases there may be pruritus (itching). Lesions are red patches that may have a white centre and petechiae (small spots of bleeding under the skin) may appear. Lesions usually last for more than 24 hours in a fixed location after which they will slowly resolve spontaneously. Ecchymoses (bruise-like patches) or hyperpigmentation (darkening of the skin) may occur in the healing process.

Urticarial vasculitis

More images of urticarial vasculitis ...

In addition to the skin lesions, patients may also develop systemic symptoms including photosensitivity, swollen lymph nodes, joint pain (50%), fever, abdominal pain (20%), difficulty breathing, and lung and kidney problems.

How is the diagnosis made?

Skin biopsy may be performed to confirm the diagnosis. Microscopic findings are those of neutrophil ‘leukocytoclastic vasculitis’, in which there is damage to small vessels in the middle layers of the skin (dermis). In some cases, a lymphocytic vasculitis is present.

Further investigation may find associated diseases. Laboratory studies may include renal function and immunological status. Chest x-ray should be performed in patients with hypocomplementaemia and breathing problems.

What is the treatment for urticarial vasculitis?

Patients with normocomplementaemic urticarial vasculitis usually have minimal or no systemic involvement and lesions often resolve on their own over time.

Treatment is based on systemic effects of the disease and extent of cutaneous involvement. To relieve cutaneous symptoms, antihistamines or non-steroidal anti-inflammatory drugs (NSAIDs) may be used.

Treatments that may be used in the long-term control of severe urticarial vasculitis that may be associated with systemic symptoms include:

• Dapsone
• Colchicine
• Hydroxychloroquine
• Indometacin/indomethacin (non-steroidal anti-inflammatory)
• Corticosteroids, e.g. oral prednisone

For cases of urticarial vasculitis that are resistant to treatment with corticosteroids other immunosuppressive agents such as azathioprine, cyclophosphamide or ciclosporin may be considered.