Cutaneous small vessel vasculitis

Small vessel vasculitides with cutaneous involvement
Most cases are idiopathic
Types
- Immune complex mediated vasculitides
  - Cryoglobulinaemic vasculitis
  - IgA vasculitis = Henoch Schönlein purpura
  - Urticarial vasculitis
- ANCA-associated vasculitides
  - Granulomatosis with polyangiitis
  - Eosinophilic granulomatosis with polyangiitis
Common clinical features
- Palpable purpuras
- Erythematous papules
- Urticaria
- Systemic symptoms
  - Fever
  - Myalgia
  - Arthralgia
  - Renal disease
Prognosis
- 90% spontaneously resolve within months
- 10% become chronic or recurrent

Cryoglobulinaemic vasculitis

Cryoglobulins = immunoglobulins that precipitate in the cold
- They precipitate within the walls of small vessels
Etiology
- Viral infections
- Autoimmune connective tissue diseases
- Haematological malignancies
Clinical features
- Palpable purpura (in 90%)
- Myalgia
- Arthralgia
- Peripheral neuropathy
- Glomerulonephritis
Diagnosis
- Examination of cryoglobulins in blood during attack
Treatment
- Treat underlying disease
- If severe
  - Steroids
  - Immunosuppressants
  - Biological therapy

IgA deposit in the vessels
Typically affect children after a respiratory tract infection
Clinical features (typical tetrad)
- Palpable purpura (in 100%)
- Arthritis
- Abdominal pain
- Haematuria
Treatment
- Self-limiting in most cases – no treatment needed
- NSAIDs
- Steroids if severe

Persistent urticaria
Associated with autoimmune connective tissue diseases
Can be due to hypocomplementemia (deficiency of complement factors)
- In which case there is also systemic involvement
Clinical features
- Recurrent episodes of painful, persistent urticarial lesions that last > 24 hours
- Angioedema can occur
Treatment
- Antihistamines
- Steroids
- NSAIDs
- Dapsone