PEDBASE.org - The Pediatric Database - Detailed information of HENOCH-SCHOENLEIN PURPURA

HENOCH-SCHOENLEIN PURPURA

DEFINITION:

A vasculitic syndrome of small vessels classically characterized by a purpuric rash, abdominal pain, arthritis, and nephritis.

EPIDEMIOLOGY:

incidence: most common form of systemic vasculitis in children
age of onset:
- 75% of cases between 2-11 years of age; mean of 5.5 years
- milder disease in those <2 years
risk factors:
- M > F (1.5-2.0:1)
- spring and autumn
- whites > blacks

PATHOGENESIS:

1. Background

antigenic stimulant -> elevated IgA levels -> IgA-mediated vasculitis in small vessels of involved organs -> necrotizing vasculitis

2. Antigenic Stimulants

1. Allergens

drugs (ampicillin, erythromycin, penicillin, quinidine, quinine)
exposure to cold
foods
horse serum
insect bites

2. Post-Infectious

bacterial - Hemophillus Parainfluenzae, Mycoplasma, Legionella, Yersinia
viral - adenovirus, EBV, parvovirus, varicella

3. Post-Vaccination

cholera
measles
paratyphoid A & B
typhoid
yellow fever

PATHOLOGY:

1. Mechanism of Vasculitis

deposition of IgA-containing immune complexes with subsequent activation of complement leads to a vasculitis
biopsy of an acute skin lesion reveals an aseptic vasculitis with fibrinoid necrosis of vessel walls and perivascular cuffing of vessels with PMN's

CLINICAL FEATURES:

1. Classical Features

100% - rash (nonthrombocytopenic purpura)
68% - arthritis
53% - abdominal pain
38% - nephritis

2. Cutaneous Manifestations

1. Classic Rash (100%)

presenting feature in 50% of cases

1. Classic Lesion

urticarial wheals, erythematous maculopapules and/or larger palpable ecchymotic-looking lesions
appear on lower extremities and buttocks
may involve upper extremities, face, and trunk

2. Petechiae or Purpura Lesions

evolve from red to purple -> rust-coloured with brownish hue -> fade
as new crops arise may give a polymorphic appearance
may be pruritic

3. Erythema Multiforme

various forms - central hemorrhage or ulceration with bullae formation

4. Angioedema

of extremities (46%) and scalp (20%)
nonpitting involving eyelids, lips, dorsa of hands and feet, back, perineum

5. Others

vesicular eruptions
swelling and tenderness of an entire limb

3. Rheumatologic Manifestations

1. Arthritis/Arthralgia (68-75%)

presenting feature in 25% of cases
tends to be periarticular
no bleeding or effusion into joints
joints swollen, tender, and painful
ankles and knees most commonly affected
rarely fingers and wrists involved
transient but may recur during active disease
no permanent deformation

4. Gastrointestinal Manifestations

1. Abdominal Pain (35-85%)

3rd most common presenting complaint
severe colicky pain with vomiting
usually follows onset of rash and joint pain

2. Bloody Stool

gross or occult with hematemesis

3. Intussusception (2-3%)

lead point a submucosal hematoma
ileoileal in 65% of cases
best diagnosed by ultrasound as barium enema may miss

4. Others

bowel infarction +/- perforation
hepatomegaly
hydrops of the gallbladder
ileal stricture
ileus
massive GI bleed
pancreatitis

5. Renal Manifestations

occur in 20-50% of cases
develop within 3 months of the onset of rash but in 3% of cases may precede rash
renal involvement more likely with:
- gastrointestinal involvement
- persistence of rash for 2-3 months
- episodic purpura
no relationship between the severity of nephritis and severity of extrarenal manifestations
complications:
- persistent nephropathy in 1%
- end-stage renal disease in <1%

1. Range of Renal Manifestations

1. Hematuria

microscopic with proteinuria <2g/d
preserved renal function
a mild form of renal disease which does not evolve into end-stage renal disease

2. Nephritic Syndrome

hematuria with hypertension, azotemia, and oliguria
proteinuria
15% develop end-stage renal disease (ESRD)

3. Nephrotic Syndrome

urinary protein excretion >40 mg/m2/hr
50% of patients with both nephrotic and nephritic syndromes develop ESRD within 10 years of onset

2. Other GU Manifestations

1. Extrarenal

1. Scrotal Swelling (2-35%)

associated with inflammation and hemorrhage of testes, appendix testes, spermatic cord, epi-didymis or scrotal wall
true torsion develops rarely

2. Renal

bladder wall hematoma
calcified ureter
hydronephrosis
urethritis

6. Neurological Manifestations

1. Central Nervous System (uncommon)

1. Headaches

most common CNS symptom

2. Altered Mental Status

apathy, hyperactivity, irritability, mood lability, somnolence

3. Seizures

partial, complex partial, generalized, status

4. Focal Deficits

aphasia, ataxia, chorea, cortical blindness, hemiparesis, paraparesis, quadriparesis

2. Peripheral Nervous System (rare)

1. Polyradiculoneuropathies

brachial plexus neuropathy, Guillian-Barre syndrome

2. Mononeuropathies

facial nerve, femoral nerve, peroneal nerve, sciatic nerve, ulnar nerve

7. Hematologic Manifestations

1. Hemorrhagic Diathesis

associated with a coagulopathy
Factor VIII and/or vitamin K deficiencies
hypoprothrombinemia
pulmonary hemorrhage -> hemoptysis
hemorrhage into large muscle groups -> pain

INVESTIGATIONS:

1. Serum

CBC - thrombocytosis in 67% of cases, leukocytosis with L shift
lytes, BUN, creatinine, albumin, amylase, liver function tests
ESR mildly elevated in 75% of cases
PT, PTT - hypoprothrombinemia
Factors VIII and XIII - decreased
serum IgA levels - elevated in 50% of cases
ASO titre - elevated in 30% of cases
CH50 - decreased in 30% of cases
C3, C4 - occasionally low
CIC (IgG & IgA) - increased

2. Urinalysis

hematuria, proteinuria
microscope - glomerular pattern - damaged RBC's and RBC casts
perform monthly x 3

3. Imaging Studies

abdominal x-ray, ultrasound, CT
barium enema
chest x-ray - pulmonary hemorrhage
testicular ultrasound

4. Biopsies

1. Skin

of purpuric lesions show leukocytoclastic vasculitis with
IgA deposits

2. Renal

LM - diffuse hypercellularity
- focal and segmental proliferation
- mesangial proliferation
minimal change to severe cresentric GN
segmental sclerosis, fibrosis, mononuclear cell infiltration
EM - mesangial, subendothelial, & subepithelial deposits
IFM - diffuse glomerular deposits of IgA, C3, fibrin, IgG, properdin and IgM
IgA deposits in the mesangium:

% of Glomeruli with Cresents (Frequency of Renal Failure)
<50 (4%)
50-75 (25%)
>75 (67%)
100 (100%)

MANAGEMENT:

Renal Failure

1. Supportive

1. Acute

adequate hydration
discontinue any exposure to antigenic stimulants, i.e., drugs

2. Long Term

weekly follow-up for first month, every 2nd week for the second month, and at the end of the 3rd month monitering

1. Clinical

cutaneous, rheumatoid, gastrointestinal, renal, and neurological manifestations

2. Investigations

CBC, electrolytes, BUN, creatinine, albumin, amylase, urinalysis, stool for occult blood

seek immediate medical attention for
- sudden onset of severe abdominal pain, distension, or bleeding
- hemoptysis (breathing up blood)
- seizures, personality changes, focal deficits, peripheral neuropathies

2. Medications

1. NSAID's

for joint and soft tissue pain

2. Corticosteroids

1. Prednisone

1-2 mg/kg/day for 5-7 days
indications:
- greater than 50% cresents on renal biopsy
- abdominal colic or GI hemorrhage
- soft tissue swelling
- scrotal swelling
- neurologic manifestations
- intrapulmonary hemorrhage
not recommended for:
- rash
- joint pain

3. Nephropathy

1. Supportive

fluid & electrolyte balance, moniter salt intake
antihypertensives

2. Experimental

immunosuppressive drugs, i.e., azathioprine (Imuran)
plasmaphoresis

4. Prognosis

1. Excellent

if no renal or neurologic manifestations or microscopic hematuria
lasts 4-6 weeks in a majority of cases
recurrences in 50% within 6 weeks but as late as 7 years
children <3 years have a shorter, milder course with fewer recurrences

2. Poor

associated with renal manifestations
progression to ESRF may not occur for years
end-stage renal failure associated with:
- HSP nephritis in children >6 yrs of age
- development of nephrotic syndrome
- crescent formation in >50% of glomeruli

Pediatric Database - HENOCH-SCHOENLEIN PURPURA

Pediatric Organization - Pedbase [at] Gmail.com