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Cutaneous vasculitis

Cutaneous vasculitis

The classical clinical lesion of vasculitis is palpable purpura, most commonly of the legs. Urticaria, erythematous swellings, vesicles, pustules, bullae, erythematous macules, papules and plaques can, however, be seen in the cutaneous eruption. Vasculitis is usually defined histologically as a process that involves the destruction of blood vessels, most often with cellular infiltrate of the vessel walls, proliferation of the intima, fibrinoid change in the vessel walls and narrowing or occlusion of the vessel lumen. Clinical manifestations vary with the site, size and depth of the vessel involved.

Cutaneous vasculitis may be confined to the skin but may be a feature of a more systemic process with involvement of organs including joints, eyes, kidney, heart, gastrointestinal tract, lungs and central nervous system. The aetiology is most often attributed to deposition of immune complexes in the vessel walls with antigen excess but can be due to nonimmunological mechanisms in which inflammation destroys the vessel wall. The clinical appearance will be critically affected by coexistent infection, drugs being taken, circulatory function, platelet numbers and function, heat, cold and local pressure.

Management of cutaneous vasculitis

Diagnosis should be confirmed by biopsy with immunofluorescence. Diseases to be excluded include Sweets syndrome, erythema nodosum, urticaria and pyoderma gangrenosum.

Drugs are frequent causes of cutaneous vasculitis. Sometimes the addition of a new drug to a variety of other drugs may tip the balance in favour of immune complex deposition although the new drug is not the primary cause, eg addition of a nonsteroidal anti-inflammatory drug (NSAID). Therefore, more than one drug may need to be stopped. Antibiotics are most frequently implicated. Other inflammatory factors induced by infection may predispose to development of vasculitis and every effort should be made to avoid using the suspect drug again. Although drugs are a frequent cause of vasculitis, vasculitis is a relatively uncommon manifestation of cutaneous adverse reactions to drugs. Many drugs have been reported as causes but those most commonly implicated are allopurinol, aminosalicylic acid, amiodarone, ampicillin, captopril, cimetidine, erythromycin, fluoroquinolones, frusemide, griseofulvin, hydralazine, iodides, methotrexate, penicillin, phenacetin, phenylbutazone, propylthiouracil, quinidine, sulfonamides, tetracyclines, thiazides and warfarin. Other exogenous chemical factors include food additives, radiocontrast media and vaccination.

Streptococcal infections, tuberculosis and leprosy can cause cutaneous vasculitis. The classical association is that of poststreptococcal involvement in Henoch-Schönlein purpura. Viral causes include hepatitis B, hepatitis C and human immunodeficiency virus.

Cutaneous vasculitis may be a manifestation of an associated disease such as rheumatoid arthritis, Sjögren’s syndrome, systemic lupus erythematosus (SLE), hypergammaglobulinaemia, cryoglobulinaemia and associated connective tissue disease, as well as hepatitis B and C. Cutaneous vasculitis has also been reported in association with lymphoma, leukemia, Hodgkin’s disease and myelodysplasias.

As cutaneous involvement is most often due to damage to capillaries and venules, small vessel involvement in other organs should be excluded. Assessing organ involvement should include a search for lymphadenopathy, hepatosplenomegaly, arthritis, conjunctivitis, episcleritis, uveitis and involvement of renal, gastrointestinal, upper and lower respiratory, and central nervous systems. A reasonable diagnostic screen includes full blood count, erythrocyte sedimentation rate, C-reactive protein, microurine, renal and liver function tests, total complement levels and antinuclear factor. If indicated, rheumatoid factor, cryoglobulins, immunoglobulins and C4 and C2 levels should be assessed. By definition, the diagnosis will have been confirmed by biopsy with immunofluorescence.

Patients should be treated with bed rest and will frequently need hospitalisation. Blistering, weeping or ulcerated areas should be treated with wet dressings, see Specific treatments of dermatitis, until the disease is stable. Painful lesions may require relief with paracetamol and codeine unless they are contraindicated. When the condition has stabilised, ulcers may be treated with an occlusive hydrocolloid dressing, see Table 4.34. Below-knee compression stockings, see Compression bandages, may hasten healing of chronic ulcerative lesions and allow for early ambulation.

Systemic therapy may not be necessary after the above measures have been followed, as there is often a tendency for gradual remission. It is difficult to generalise, as individual entities may require specific therapies. If a clear removable cause has not been established and the distribution and number of lesions continues to extend, or if there is involvement of other organ systems such as the kidney, lung or joints then the usual treatment is with systemic corticosteroids. Use

prednisolone 1mg/kg orally, daily.

Tapered reduction of the prednisolone can be commenced once new lesions cease to appear. If control is not achieved with corticosteroids then additional corticosteroid-sparing agents such as azathioprine or cyclophosphamide may be added. Other drugs used in cutaneous vasculitis, depending on the course and severity of the disease, include

dapsone 50 to 100mg OR colchicine 1.5 to 3mg OR hydroxychloroquine 200mg orally, daily.

These drugs are effective against the neutrophilic forms of cutaneous vasculitis. Colchicine inhibits neutrophil chemotaxis.

If cutaneous involvement or arthralgia are the only features and the disease is stable, use

an NSAID (see Table 1.3 for recommended regimens).

Less frequently used options include oxpentifylline or a combination of aspirin and dipyridamole where there is an element of small vessel occlusion. Antihistamines, eg cetirizine, may have a place in early symptomatic treatment where itch is prominent or where there is an urticarial component.

Specific clinical entities of cutaneous vasculitis

This cutaneous necrotising vasculitis is diagnosed on the basis of immunofluorescent findings of IgA antibodies deposited in and around cutaneous blood vessels. Similar appearances are evident in kidney biopsies. The disease was formerly described predominantly in children following upper respiratory tract infection and associated with joint, gastrointestinal tract and renal involvement as well as skin rash. However, the diagnosis is frequently made in adults solely on the basis of the immunofluorescence findings and compatible skin lesions. Management is similar to that described for other forms of cutaneous vasculitis with systemic involvement and also includes adequate follow up to detect sequelae (see Management of cutaneous vasculitis).

Livedo is common in minor forms in otherwise normal women. The finding of an accentuated, broad, net-like pattern of cyanotic discolouration is seen particularly on the skin of extremities and is associated with small to medium vessel arterial disease or where sluggish skin blood flow is caused by increased viscosity, eg in antiphospholipid antibody (APL) syndrome. Livedo may be associated with cerebral ischaemic episodes in APL syndrome. When associated with nodular vasculitis it is known as cutaneous polyarteritis nodosa. Livedo that does not disappear with vasodilatation due to high ambient temperature, or is patchy or broken, is more likely to be of pathological significance.

This is a form of nodular vasculitis confined to the skin where erythematous nodules, usually on the lower legs, are associated with livedo reticularis. This form of polyarteritis nodosa is not life threatening but may have significant morbidity. Treatment is with bed rest, NSAIDs and exclusion of precipitating factors.

When urticaria-like lesions persist for 24 to 48 hours and particularly if they fade with bruising, the possibility of urticarial vasculitis would be entertained. There is usually an association with low levels of complement and biopsy confirms vasculitis. Management is by excluding associated conditions such as SLE or possible drug causes and exclusion of involvement of other organs such as the kidney, joints and lungs. If systemic therapy is indicated (see When should systemic therapy be used?) and the patient is unresponsive to antihistamines, use

prednisolone 25 to 50mg orally, daily for 1 week then taper the dose over 2 to 3 weeks.

If there is no response, try indomethacin, colchicine, dapsone or hydroxychloroquine as shown in When should systemic therapy be used? Plasmapheresis has been used for severe, refractory disease.

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