PBL #3 Flashcards
1
Q
What is the incidence of HSP?
A
20-27/100,000 children
and
1-2/100,000 adults
***Peaks from December to March
2
Q
What are the risk factors for HSP?
A
- Infections
- Streptococcus, Parvo B19, Hep B/C, HIV, Bartonella, Salmonella, Shigella, Staph aureus
- Toxins
- Drugs: ACE-I, ARBs, ABx, NSAIDs
- Genetics
- HLA-B35 and HLA-DQA1
- family members with HSP
- Associated conditions
- Familial Mediterranean Fever
- Inflammatory Bowel Disease
3
Q
What populations are affected by HSP?
A
- Most affected:
- 90% of cases reported in children <10 yoa
- males more likely
- Can affect all ages!
4
Q
What are the histopathologic signs of IgA vasculitis?
A
- leukocytoclastic vasculitis
- with or without fibrinoid necrosis
- immunofluorescence
- perivascular IgA deposition
- renal histology:
- diffuse hypercellularity
- focal and segmental proliferation
- mesangial proliferation
- segmental sclerosis fibrosis
- mononuclear cell infiltration
- diffuse glomerular deposits of IgA/C3/fibrin/IgG
- IgA deposits in mesangium
- severe cases → circumferential crescents in glomeruli
5
Q
What is a nephrotic syndrome?
A
- massive proteinura
- hypoalbuminemia (peeing out albumin)
- edema
- hyperlipidemia/hyperlipiduria
6
Q
What is a nephritic syndrome?
A
- hematuria
- oliguria (small urine output)
- azotemia (elevated BUN and serum creatinine)
- hypertension
- less severe than nephrotic syndrome
7
Q
How should physician interact with a 9 year old needing intrusive procedures?
A
- developmentally appropriate
- give children the sense of industry and competence
- offer them the opportunity to control as much as is reasonable
- NEVER ask parents to restrain their children
- staff should restrain child
- Do ask parents to comfort child during procedure
8
Q
What is the quick & dirty pathophysiology of HSP?
A
- IgA complex formation
- IgA complex deposition systemically
- Type III Hypersensitivity
- Leukocytoclastic vasculitis
- destruction of white blood cells causing inflammation in blood vessels
- Blood vessel necrosis: “stuff” leaks out
- Skin → palpable purpura
- GI → pain, bleeding
- Kidney → damage to GBM → leaking
- proteinuria
- hematuria
9
Q
What are common physical examination findings associated with HSP and HSPN?
A
- Skin rash:
- painless palpable purpuric rash
- GI:
- abdominal pain →colicky, usually periumbilical or epigastric
- vomiting, hematemesis, blood in stool
- Joint pain:
- usually involves large joints of lower extremities
- Renal:
- hematuria
- oliguria, anuria
- Nonspecific:
- fever, malaise, fatigue
- recent URI
10
Q
What is an appropriate differential diagnosis list for this patient’s presenting symptoms and exam findings?
A
- granulomatosis with polyangiitis (Wegener’s)
- polyarteritis nodosa
- Takayasu arteritis
- Systemic lupus erythematosus (SLE)
- Idiopathic thrombocytopenic purpura (ITP)
- Hypersensitivity vasculitis
- Juvenile rheumatoid arthritis (JRA)
- Hemolytic uremic syndrome (HUS)
- IgA Nephropathy (Berger’s)
- Rocky Mountain Spotted Fever (RMSF)
11
Q
What are the pharmacological treatments of HSP?
A
-
Supportive
- unless crescents found on renal biopsy → indicates crescentic glomerulonephritis
- Tx if crescentic glomerulonephritis (biopsy):
- high dose steroids combined with cyclophosphamide or daily mycophenolate mofetil
- Tx of HTN:
- ACE inhibitor, diuretic
- Corticosteroids - Prednisone
- Azathioprine
- Mycophenolate Mofetil
- Acetaminophen
12
Q
What areas of the nephron affected by HSP?
A
- Glomerular tuft
- capillaries
- Mesangium/mesangial cells
- Endothelial cells of glomeruli
- Podocytes
- Glomerular basement membrane
13
Q
What is the developmental impact of illness and care on school aged children and their families?
A
- assist children to manage changes in their health states in a manner which enhances growth
- concrete operations stage of cognitive development
- where cause and effect are highlighted, and thinking into the future is not a strength
- Rely on their task-orientation and be specific about what you need them to do
14
Q
What are two reasons blood pressure may be increased in persons with renal injury?
A
- Inability to remove wastes or excess salt
- excess fluid → volume expansion
- Tubuloglomerular Feedback
- Decreased GFR (Mesangial proliferation in our case) → decreased tubular flow rate → increased fractional absorption of NaCl (increased time for tubules to reabsorb NaCl) → decreased concentration of NaCl in Macula Densa → PG release onto Juxtaglomerular Cells → RAAS Release → Vasoconstriciton and Sodium Reabsorption
15
Q
How does creatinine represent GFR?
A
- Creatinine is completely filtered
- filtered load of creatinine = excretion rate
- not secreted (tiny bit), reabsorbed, destroyed or produced
- GFR = (Urine Filtration Rate x [Crurine]) / [Crplasma]
- GFR = 186.3 x (serum creatinine-1.154)
- x (age-0.203)
- x 1.212 if African American
- x 0.742 if female
