Assessment and management of leukocytoclastic vasculitis

Leukocytoclastic vasculitis (LCV) typically presents as palpable purpura (nonblanching palpable rash) on the lower legs. If the patient has a widespread or rapidly spreading vasculitic rash, significant blistering and ulceration (causing pain or discomfort), and is febrile and unwell, urgently refer to the nearest hospital emergency department.

Nonurgent cases should be referred to a specialist. The presence and extent of systemic involvement, and whether the patient is clinically unwell, determine the urgency of specialist referral.

Assess for systemic involvement and, if possible, identify the cause by taking a thorough history, performing a physical examination and ordering investigations. Investigations for patients with suspected LCV are listed in Investigations for patients with suspected leukocytoclastic vasculitis to determine urgency of specialist referral. Liaise with a specialist for advice on biopsy technique (if required) and initial investigations as appropriate.

Note: Mild leukocytoclastic vasculitis is usually self-limiting, with lesions lasting about 3 weeks.

Mild LCV (ie no systemic involvement and patient is not unwell) is usually self-limiting, with lesions lasting about 3 weeks. Mild LCV may not require urgent specialist referral or biopsy; however, monitor closely because the condition can progress rapidly. Address the cause if it is identified (eg treat any infection, stop causative drugs). Evidence for using topical corticosteroids in treatment of mild LCV is lacking. Measures to reduce peripheral oedema (eg below–knee support stockings, bed rest) are useful. If a nonsteroidal anti-inflammatory drug (NSAID) is not the cause of LCV, an NSAID can be used to relieve discomfort.

If no clear cause is identified, or the LCV progresses or is persistent, urgently refer for specialist assessment. Specialist treatments may include oral corticosteroids, and steroid-sparing agents such as hydroxychloroquine, colchicine, dapsone or immunosuppressive agents.

Figure 1. Investigations for patients with suspected leukocytoclastic vasculitis to determine urgency of specialist referral.

[NB1]

Standard investigations (to confirm diagnosis and determine severity of systemic involvement)

skin biopsy [NB2]

full blood count

kidney function and liver biochemistry

urine microscopy, protein and culture [NB3]

CRP and ESR

blood cultures (if febrile or unwell)

streptococcal serology (particularly in children)

Additional investigations (depending on clinical presentation, to investigate for causes)

ANA

ENA

dsDNA

ANCA

rheumatoid factor

anti–CCP antibodies

complement level (C3 and C4)

hepatitis B and C serology

HIV serology

cryoglobulins [NB4]

serum protein electrophoresis

24-hour urinary protein excretion and creatinine clearance

Note:

ANA = antinuclear antibodies; ANCA = antineutrophil cytoplasmic antibodies; anti–CCP = anti–cyclic citrullinated peptide; CRP = C-reactive protein; dsDNA = double stranded DNA; ENA = extractable nuclear antigen; ESR = erythrocyte sedimentation rate; HIV = human immunodeficiency virus

NB1: Liaise with a specialist for advice on appropriate initial investigations.

NB2: Skin biopsy is required to confirm diagnosis of leukocytoclastic vasculitis; liaise with a specialist for advice on appropriate biopsy technique (eg for histology and direct immunofluorescence). Skin biopsy should ideally be performed before starting oral or systemic corticosteroid therapy because systemic corticosteroids can affect skin biopsy results.

NB3: To investigate for kidney involvement—for example, urine microscopy for glomerular haematuria and cellular casts (specify phase-contrast microscopy), and detection and measurement of proteinuria (eg urine dipstick, spot protein to creatinine ratio)

NB4: Not all pathology laboratories perform cryoglobulin testing.