Urticarial vasculitis

Question 1

What is the gender prevalence of urticarial vasculitis?

Answer 1

More common in women

Urticarial vasculitis is rare, occurring in approximately 0.025% of the population.

Question 2

What percentage of patients with chronic urticarial illness have urticarial vasculitis?

Answer 2

1-20%

Most cases are normocomplementaemic, which is considered benign.

Question 3

What is the average duration of urticarial vasculitis?

Answer 3

3 years

Question 4

During which decade of life does urticarial vasculitis peak?

Answer 4

4th decade

Question 5

What type of hypersensitivity reaction is involved in the pathogenesis of urticarial vasculitis?

Answer 5

Type III mediated hypersensitivity reaction

Question 6

What is the primary vascular structure affected in urticarial vasculitis?

Answer 6

Postcapillary venules in the superficial dermis

Question 7

What is a common feature of the vascular endothelial damage in urticarial vasculitis?

Answer 7

Deposition of IgG, IgM, and C3 within and around the vessel wall

Question 8

What is the most common cause of hypocomplementaemia in urticarial vasculitis?

Answer 8

Complement activation via the classical complement pathway

Question 9

What are common associations with urticarial vasculitis?

Answer 9

• Idiopathic
• AICD (e.g., SLE, Sjogren)
• Cryoglobulinaemia
• Drugs (e.g., NSAIDs)
• Viral infections (e.g., chronic hepatitis B, C)
• Haematological malignancies
• Serum sickness

Question 10

What are the clinical features of urticarial vasculitis?

Answer 10

• Erythematous, indurated wheals
• Lesions persist >24 hours
• Associated with burning pain
• Resolve with post-inflammatory hyperpigmentation

Question 11

What criteria are used to diagnose Hypocomplementaemic Urticarial Vasculitis Syndrome (HUVS)?

Answer 11

2 major criteria and 2 minor criteria

Major: Urticaria for 6 months, hypocomplementaemia. Minor: Vasculitis on biopsy, arthritis, uveitis, glomerulonephritis, recurrent abdominal pain, positive C1q precipitin test.

Question 12

What is the most common extracutaneous manifestation of Hypocomplementaemic Urticarial Vasculitis (HUV)?

Answer 12

Musculoskeletal symptoms

Question 13

Which lab levels are commonly abnormal in urticarial vasculitis?

Answer 13

• Raised ESR
• Low C3
• Low C4
• ANA

Question 14

What should be included in the initial workup for urticarial vasculitis?

Answer 14

Initial work up:
* Lesional skin biopsy (diagnostic), over 12hrs old, may need several bx
* Full blood count
* C-reactive protein, erythrocyte
* sedimentation rate
* Biochemical profile
* Complement profile: C3, C4 , C1q and anti-C1q antibodies (serial testing)
○ differentiating between normocomplementaemic
and hypocomplementaemic disease
* Antinuclear antibodies
* Anti-extractable nuclear antigens
* Circulating immune complexes
* Urinalysis, liver function tests - systemic Involvement
If abnormal urinalysis - ideally 24hr protein and creatinine clearance

Depending on clinical presentation:
· Direct immunofluorescence studies of skin -if suspect HUV/HUVS, must be <3hr lesion
· biopsy
· C1q anti-C1q antibodies
· Cryoglobulins
· Hepatitis B and C serology
· Thyroid function and autoantibodies
· 24-h urine protein and creatinine clearance
· Serum protein electrophoresis
· Chest X-ray, lung function tests
Assessment of visual acuity and slit lamp examination

Question 15

What are key histopathological findings in urticarial vasculitis?

Answer 15

• Leukocytoclasis
• Wall necrosis
• Perivascular inflammation
• Fibrinoid deposition
  ○ Deposition of IgG and IgM and C3 within and around the vessel wall and at the dermoepidermal junction granular pattern is a comm on feature

Question 16

What is a key differential diagnosis for urticarial vasculitis?

Answer 16

• Other urticarias, particularly delayed pressure urticaria.
• ○ Adult onset Still disease
  ○ Schnitzler syndrome
  ○ Cryopyrin associated periodic syndrome (chap 45)
• Other diseases with urticaria-type lesions
  ○ EM (atypical)
  ○ Urticaria multiforme
  ○ SLE
  ○ Early BP
  ○ Sweets
  ○ Tumid lupus

Question 17

What is the first-line treatment for urticarial vasculitis?

Answer 17

• Non-sedating antihistamines
• Short trial of corticosteroids

Question 18

What are the second-line treatments for urticarial vasculitis?

Answer 18

• Dapsone 75-100 mg/day
• Colchicine 1-1.5 mg/day
• Hydroxychloroquine 200-400 mg/day

Question 19

What treatments are considered for severe refractory cases of HUV or HUVS?

Answer 19

• Azathioprine
• Ciclosporin
• MMF
• Methotrexate
• IVIG
• Cyclophosphamide
• Omalizumab
• Rituximab
• TNF antagonists

Question 20

Ix for HUVS

Answer 20

○ HUVS - low complement level, presence of anti-C1q precipitin, low c1q