A rare multiorgan disease caused by systemic vasculitis of veins and arteries of all sizes, hypercoagulability and neutrophil hyperfunction; cause is unknown

Aetiology

• The disease is more common in people from Turkey, the Mediterranean and Japan
• It affects is more common in people with HLA-B51 positivity

Clinical features

• Recurrent oral ulceration
• Recurrent genital ulceration
• Uveitis (anterior or posterior)
• Erythema nodosum
• Vasculitis including retinal vasculitis
• Acneiform lesions
• Superficial thrombophlebitis at venepuncture sites
• Pathergy (i.e. pustules at sites of puncture or minor trauma)
• Arthralgias and arthritis in 50%

Investigations

• Bloods:
  • Rheumatoid factor
  • ANA
  • ANCA
  • Angiotensin-converting enzyme levels
  • HLA B51
• The pathergy test can be used in certain scenarios but can be unreliable
  • This is characterised by exaggerated skin injury after minor trauma (skin prick using a sterile needle) when reassessed at 48 hours to see if a papule/ pustule has formed
• Imaging and biopsy:
  • Central nervous system imaging +/– lumbar puncture may be appropriate for neurological symptoms
  • Endoscopy may be required to investigate GI symptoms to rule out inflammatory bowel disease
  • High-resolution CT may be required for patients presenting with haemoptysis
  • An ophthalmologist should review patients with eye symptoms
  • Biopsies may show vasculitis with neutrophilic infiltration of small- and medium-sized blood vessels

Management

• Some patients only require treatment to cover a flare, whereas others require immunosuppressive treatment with biologic drugs