HSP

o	small-vessel leukocytoclastic vasculitis 
o	tissue deposition of Ig-A containing immune complexes in affected organs
o	Classic tetrad
o	Rash
o	Abdominal pain
o	Arthritis/arthralgia
o	Glomerulonephritis
o	Unknown aetiology 
o	Immune mediated
o	Infectious triggers proposed
o	Genetic factors implicated
o	Can be drug related
o	All of these correlations are unproven/unclear
o	Epidemiology
o	Mainly children
o	3-15 yrs
o	50% of cases < 5
o	Incidence in America 13.5 in 100, 000
o	More in whites
o	Males > females 2:1
o	History/Examination
o	Male, 3-15 yrs, prior URTI (more common in colder months)
o	Arthralgias
	Often assoc. with oedema
	Ankles/knees most common
	Present in ~80% of patients
o	Abdo pain
	In 50% pts. + nausea/vomiting
o	Rash
	Palpable purpure, typically non-blanching
	Can occur anywhere, usually in lower extremeties
	Occurs in ALL patients
o	Renal symptoms
	Half patients
	Haematuria/proteinuria/rbc casts
o	Uncommon historical features
o	Certain medications may be assoc.
	Antibiotics/phenytoin
o	13% can have scrotal pain/swelling
o	Extremely rare
	Headache/seizures/pulmonary haemorrhage
o	Investigation
o	1st tests
	Urinalyis
•	Rbcs/proteinuria/casts
	24 hour urine for protein
•	Looking for renal involvement
o	Tests you can consider
	Serum IgA
	Serum Creatinine/EUC
	Coagulation studies (should be normal in HSP)
	Skin biopsy
o	DDx
o	ITP
	Low platelets in ITP, normal in HSP
o	Hypersensitivity vasculitis
	Usually doesn’t have renal involvement
	Skin biopsy to prove otherwise
o	Wegeners uncommon in kids
o	SLE uncommon in kids
o	RA
	Different age/different rash
o	Meningococcal septicaemia
	Abnormal coagulation / low platelet
o	Treatment (cortico are 1mg/kg/day for 3 months)
o	Depends on severity
o	Without nephritic-range proteinuria/GFR decline
	Just joint pain
•	Analgesics
	With severe oedema/scrotal involvement/abdo pain
•	Oral corticosteroids
•	Rest hydration elevation
o	Nephritic range protein uria
	Corticosteroids 
	If rapidly progressive nephritis
•	Add immunosuppressants (cyclophosphamide for 12 weeks)
	Adjuncts
•	Plasmapheresis
o	Efficacy unknown as usually given with other treatments
•	Renal dialysis/transplant
o	Follow up
o	For at least 6 months with periodic urinalysis and BP monitoring
o	Usually excellent prognosis
o	Complete recovery in 94% kids and 89% adults
o	One third of patients have a recurrence within 4 months, but next episode is milder→