Prof David Jayne
Consultant Nephrologist,  Addenbrookes Hospital, Cambridge

August 2021 

Urticaria is the name used to describe a raised itchy rash, also called hives. There are a number of causes but the symptoms are usually short lived and subside within hours. When urticaria occurs for longer periods of time, days or weeks, the blood vessels under the skin can show evidence of vasculitis and the term urticarial vasculitis is used. Patients may experience a burning or painful sensation and there is skin discolouration when the rash subsides. It is a form of skin vasculitis.

Urticarial vasculitis can be seen as a skin manifestation of another form of systemic vasculitis, such as, EGPA (Churg-Strauss) or IgG4 related disease, and like other forms of vasculitis, urticarial vasculitis may be triggered by another disease process, infection or cancer, or a drug. It has particularly been associated with hepatitis virus infection but most cases have no identified cause. It is either limited to the skin or with evidence of systemic disease. The systemic disease is quite rare and not well characterised, but arthritis, glomerulonephritis (kidney involvement), lung and gastro-intestinal disease have been reported. Patients with systemic disease feel unwell, with fevers, muscle and joint pains and the CRP (inflammation) blood test is usually high. 

Some cases of urticarial vasculitis are associated with changes in the blood complement system with falls in the level of complement components C3, C4 or C1q in the blood, or the presence of anti-C1q antibodies. This has been called hypocomplementemic urticarial vasculitis (HUV). These complement abnormalities can also be seen in SLE (lupus), although anti-nuclear antibodies are seen in some cases of HUV, this would further raise suspicion that the correct diagnosis is lupus. HUV has also been called MacDuffie syndrome, with one attempt at defining diagnostic criteria requiring 2 of, biopsy confirmed urticarial vasculitis, arthritis, eye inflammation, glomerulonephritis, abdominal pain and anti-C1q antibodies. Systemic disease is more common than when complement abnormalities are not present and the possible overlap with lupus has encouraged use of drugs effective in lupus such as hydroxychloroquine and rituximab.

Who are affected?

Urticarial vasculitis is most common between the ages of 30-40 and is found in women more than men. Very rare cases of HUV have been familial, more than one case in the family.


As in other types of vasculitis, the diagnostic work up tries to define abnormal clinical, laboratory and X-ray features, identify any associated diseases and then classify the type of vasculitis that is present. A skin biopsy can be helpful as there are characteristic findings in urticarial vasculitis, a search for disease in other organs should be undertaken.

Key blood tests would include inflammation markers, CRP and ESR, testing for C1q, anti-C1q, C3 and C4 complement components and autoantibodies, ANA and ANCA. The occurrence of a rash and complement abnormalities would also raise suspicion for cryoglobulinemia. Chronic virus infections, other infections and inflammatory diseases and cancer should be looked for and excluded.


There is no high quality evidence from clinical trials to help guide treatment in urticarial vasculitis. The skin manifestations of Urticarial Vasculitis may simply be treated with antihistamines and NSAIDs such as Ibuprofen. Hydroxychloroquine, an anti-malarial, dapsone and colchine can be tried especially for relapsing disease. Corticosteroids work well but relapse can occur on withdrawal and they are more toxic. The presence of systemic disease usually demands the combination of higher dose steroids with an immune suppressant such as such as azathioprine, cyclophosphamide, mycophenolate mofetil or methotrexate. Other therapies that have been effective include high dose intravenous immunoglobulin, omalizumab (used in asthma), plasma exchange, anti-interlueukin 1 biologics and rituximab.

A logical approach to treatment is required trying to avoid steroids as far as possible for skin limited disease. Without good data to help select drugs a sequence of treatments may be required until one is found that works well for that patient.

Patient monitoring to detect the emergence of systemic disease or another underlying diagnosis is important, although after 1-2 years patients often settle into a pattern of quiet periods and flares, that may be triggered by intercurrent infection, and treatment strategies for prompt flare management are worked out.

Drugs and Side Effects

For information on the main drugs prescribed for Urticarial Vasculitis see our Glossary of Drugs.


Procedures: Plasma exchange or plasmapheresis

This treatment is sometimes used in patients with severe vasculitis where antibodies in the blood are thought to be important in causing the disease. The treatment involves removing antibodies from the blood using a machine and returning the “cleaned” blood back to the patient. The treatment may necessitate giving blood products to the patient including plasma, albumin or immunoglobulin. It may also involve giving drugs to thin the blood and prevent it clotting in the machine.

For information on plasma exchange:


Key Points

·       Uritcarial vasculitis can be a feature of another disease or a disease on its own.

·       It can be limited to the skin or have systemic manifestations

·       There may be complement abnormalities in the blood, in which case the term hypocomplementemic urticarial vasculitis is used. 

·       Treatment follows similar principles and drugs to other forms of vasculitis. 

Related Vasculitis Articles

Sent from my iPad