Vasculitis

Vasculitis describes a condition in which there is inflammation of the blood vessels. They may be damaged by the inflammatory process.

Vasculitis can be primary, or secondary (as a result of infection, or in association with some chronic diseases including rheumatoid arthritis).

Vasculitis is rare. Around 3,000 people in the UK develop one of its various forms every year.¹

• Idiopathic (45-55%).
• Infection (15-20%) e.g. Henoch-Schonlein purpura, septic vasculitis, upper respiratory tract flares of Wegener's granulomatosis, polyarteritis nodosa ( PAN).
• Inflammatory disease (15-20%) e.g. Systemic lupus erythematosus, rheumatoid arthritis, Crohn's disease and ulcerative colitis.
• Drug induced ( 10-15%) e.g. sulfonamides, Beta-lactams, quinolones, NSAID's, oral contraceptives, thiazides, anti-influenza vaccines. Chemicals such as insecticides and petroleum products.
• Neoplastic (<5%) e.g. as a result of a paraproteinaemia or lymphoproliferative disorder.

Many attempts have been made to classify this group of diseases and several classifications are in existence. One of the simplest being that which classifies them according to the size of the vessel involved.

Vasculitis can affect any system producing an almost infinite range of symptoms. Frequently however, the initial presentation of a vasculitis will be as a skin lesion.

Diagnosis of the skin lesion can provide information as to what calibre of vessel may be involved, potential diagnosis, and where else in the body evidence of vasculitis should be sought (see below).^2,3

Full history should be taken particularly with respect to:

• Length of symptoms/signs
• Recent illness
• Recent exposure to drugs, vaccines and chemicals
• Other symptoms e.g. arthralgia, cough, ENT symptoms, numbness and paraesthesia
• Detailed review of all systems

In view of the systemic nature of many vasculitic diseases, a complete physical examination should be carried out including central nervous system and ENT examination.

All patients suspected of having a vasculitic lesion should have the following investigations performed:

• FBC and differential cell count
• U&Es
• Liver function tests
• Urine culture, microscopy
• Urine dip test for glucose, protein and blood
• Hepatitis serology (Types B and C are associated with PAN and mixed cryoglobulinaemia respectively)
• Cryoglobulins
• Compliment levels
• Rheumatoid factor
• CXR

Also consider:

• Cardiac echo and blood cultures if cardiac murmur present.
• Anti nuclear antibodies (ANA) if medium sized vessel involvement and any suggestion of connective tissue disease.
• Skin biopsy taken during the acute stage.

There are several other conditions which may mimic cutaneous vasculitis and these must be considered when arriving at a diagnosis. Some of the more common ones include:

• Insect bites
• Trauma
• Pigmented lesions
• Purpura e.g. due to low platelet count
• Disseminated intravascular coagulopathy
• Pityriasis lichenoides

Approximately 50% of patients presenting with cutaneous vasculitis will have a treatable cause. The treatment will vary considerably according to the underlying cause:

• Avoiding the precipitating factor, such as drugs or chemicals.
• Treatment with corticosteroids, methotrexate, cyclophosphamide, azathioprine and other chemotherapeutic agents.⁴ Treatment is based on the organs affected and the overall condition of the patient.
• In general, corticosteroids are administered to control acute symptoms and laboratory evidence of systemic inflammation. After control is achieved, attempts may be made to taper dosing over a month.
• For patients with renal or CNS involvement, immunosuppression with cyclophosphamide, azathioprine, methotrexate or tumour necrosis factor blockade⁵ is used.⁶ Use of immunosuppressants and biological agents also enables reduction in steroid dose.
• Morbidity due to cumulative corticosteroid dose (as well as toxicity from immunosuppression) must be weighed in the long-term plan of care.

Surgical

Stenting of stenotic vessels is increasingly used. Balloon dilatation has also been used to improve renovascular flow.
Patients with Wegeners granulomatosis may develop subglottic stenosis, which is amenable to balloon dilatation.

• ESR may be used as a marker of disease activity.
• Patients with elevated c-ANCA titres may have normal levels during periods of disease control and increasing ones with disease activity.

This is related to the degree of end-organ involvement.

• Renal insufficiency
• Digital gangrene
• Pulmonary haemorrhage
• Central nervous system infarction
• Arterial or venous thrombosis
• Subglottic stenosis