Henoch-Schonlein Purpura Flashcards
What is Henoch-Schonlein Puprura (HSP)?
A small vessel vasculitis with particular characteristics
What are the characteristics of HSP?
- Skin rash on extensor surface
- Arthralgia
- Periarticular oedema
- Abdominal pain
- Glomerulonephritis
What age range is HSP most common in?
3-10 years
When does the incidence of HSP peak?
In winter months
How does HSP begin?
Genetic predisposition and antigen exposure increases circulating IgA levels and disrupts IgG synthesis
What happens to IgA and IgG in HSP?
They interact to form complexes that activate complement and are deposited in affected organs precipitating an inflammatory response with vasculitis
What are the risk factors for HSP?
- Male
- White
- Asian
What are the symptoms of HSP?
- Fever
- Rash
- Joint pain
- Colicky abdominal pain
If there is GI involvement in HSP how can this present?
Haematemesis and melena
Describe the rash in HSP
Initially urticarial then maculopapular, purpuric and palpable
Where does the rash in HSP typically affect?
Buttocks and extensor surfaces
What is normally spared by the HSP rash?
The trunk
How many patients with HSP are affected by arthralgia?
2/3
What joints are particularly affected by arthralgia in HSP?
Knees and ankles
What is diagnosis based on?
Combination of symptoms with supportive tests
Why can diagnosis be made on symptoms alone?
Very few conditions present in the same way
What supportive tests can be used in diagnosing HSP?
- Bloods
- Urine dipstick
- Renal biopsy
- Skin biopsy
- Abdominal investigations
What may be elevated in bloods in HSP?
- Creatinine
- Urea
- CRP
What are the urine dipstick findings in HSP?
Microscopic or macroscopic haematuria or mild proteinuria in 80% of patients
When may renal biopsy be indicated?
To establish diagnosis or assess severity of suspected kidney disease
What are the main findings on renal biopsy?
Increased cells and Ig deposition in the mesangium
Is skin biopsy necessary?
Only rarely
What might skin biopsy show?
Leucocytoclastic vasculitis
What may atypical HSP be confused for?
- Papular urticaria
- SLE
- Meningococcemia
Does HSP usually require treatment?
No - most have a benign course that resolve in 6 weeks
What medication may be needed whilst HSP resolves?
NSAIDs to treat arthritis
What can be used to manage severe abdominal pain in HSP?
Steroids
What should occur after HSP has resolved in children with persistent renal symptoms and that required treatment?
Long-term follow-up
What is long-term follow-up to look for?
CKD and hypertension
When may hypertension and CKD develop after HSP?
After several years
What are the potential complications of HSP?
- Intussusception
- Ileua
- Protein-losing enteropathy
- CNS invovlement
- Progressive CKD
What are the risk factors for developing CKD after HSP?
- Heavy proteinuria
- Oedema
- Hypertension
- Deteriorating renal function
